Sewage treatment comprehensive energy utilization system and method

Abstract

The invention belongs to the technical field of sewage treatment and resource recovery, and relates to a sewage treatment comprehensive energy utilization system and method.The sewage treatment comprehensive energy utilization system is characterized in that a sewage treatment module water outlet area communicates with a reclaimed water recycling module, and the reclaimed water recycling module communicates with a pumped storage module and a water source heat pump module; a sludge outlet area of the sewage treatment module and the kitchen garbage are communicated with the biogas combined heat and power generation module through the sludge treatment module; the sludge treatment module is externally connected with a biogas purification device and a nutrient soil manufacturing device; the biogas combined heat and power generation module, the pumped storage module and the water source heat pump module are externally connected with a power pipe network and a heat pipe network. According to the invention, sewage treatment, reclaimed water reuse, biogas combined heat and power generation, nutrient soil manufacturing and other modules are organically combined, potential values of sewage, sludge and kitchen waste are fully excavated, efficient utilization of resources is realized, and waste of resources in a traditional treatment mode is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment and resource recovery, and in particular to a sewage treatment integrated energy utilization system and method. Background Art

[0002] As environmental protection policies continue to advance, the wastewater treatment industry is undergoing profound changes. Traditional wastewater treatment plants focus on treating pollutants in wastewater to meet discharge standards. However, as society continues to demand more efficient resource utilization and environmental protection, traditional wastewater treatment models have gradually revealed their limitations, making them unable to meet the demands of sustainable development in the new era.

[0003] Traditional sewage treatment plants have the sole objective of achieving pollutant discharge standards. This single-minded operating model has led to numerous problems:

[0004] First, in traditional treatment processes, treated effluent is usually discharged directly into natural water bodies, failing to fully tap the potential value of recycled water. At the same time, sludge disposal is mainly done through landfill and incineration, which not only occupies a large amount of land resources but may also cause secondary pollution. Moreover, the methane and organic matter resources contained in the sludge are not effectively recycled, further exacerbating the waste of resources.

[0005] Second, traditional sewage treatment plants lack energy self-sufficiency. Aeration, pumping and other links in the sewage treatment process consume a large amount of electricity, and their energy consumption accounts for more than 70% of the total energy consumption of the entire plant.

[0006] Existing sewage treatment technology mainly focuses on the single function of sewage purification, and fails to coordinate the development and comprehensive utilization of multiple resources such as water, energy, and mud. This single-function treatment model makes it impossible for sewage treatment plants to achieve efficient resource utilization and energy self-sufficiency, limiting their sustainable development capabilities.

[0007] In summary, existing wastewater treatment technologies are unable to meet the environmental protection policy requirements for efficient resource utilization and low carbon emissions. Therefore, it is of great practical significance and urgency to develop a comprehensive wastewater treatment energy utilization system and method that can achieve the coordinated development of water, energy, and mud resources, improve energy self-sufficiency, reduce carbon emissions, and achieve global optimization. Summary of the Invention

[0008] In order to solve the above existing technical problems, the present invention provides a sewage treatment integrated energy utilization system.

[0009] The technical solution of the present invention is realized through the following scheme: A comprehensive sewage treatment and energy utilization system, including sewage, a sewage treatment module that can decompose sewage into treated water and sludge, a reclaimed water reuse module, a kitchen waste conveying pipe, and a sludge treatment module. The water outlet area of the sewage treatment module is connected to the reclaimed water reuse module. The reclaimed water reuse module is respectively connected to a pumped storage module and a water source heat pump module. The sludge outlet area of the sewage treatment module and the kitchen waste are both connected to a biogas cogeneration module through the sludge treatment module. The sludge treatment module is also externally connected to a biogas purification device and a nutrient soil manufacturing device;

[0010] The biogas cogeneration module is externally connected to an electric power grid and a heat pipeline network. The pumped storage module is externally connected to an electric power grid. The water source heat pump module is externally connected to a heat pipeline network.

[0011] Preferably, the pumped storage module includes a reclaimed water pipeline network, a high-level regulating reservoir, and a power station. The reclaimed water pipeline network is connected to the high-level regulating reservoir through a water delivery pipeline. The high-level regulating reservoir is connected to the power station and a water return pipeline through a water outlet pipeline. A first valve is provided between the reclaimed water pipeline network and the water delivery pipeline. A third valve is provided between the water outlet pipeline and the power station. The water return pipeline is connected to the reclaimed water pipeline network. A second valve is provided between the water return pipeline and the reclaimed water pipeline network.

[0012] Preferably, the water outlet end of the power station and the drainage end of the reclaimed water pipeline network are both externally connected to a river.

[0013] Preferably, the reclaimed water reuse module includes a first clear water tank, a second clear water tank, a third clear water tank, and a water distribution pump house. The first clear water tank, the second clear water tank, and the third clear water tank are all connected to a clear water tank inlet channel through an inlet sluice. The first clear water tank, the second clear water tank, and the third clear water tank are all connected to the water distribution pump house through an outlet sluice. The first clear water tank and the second clear water tank are both connected to the water source heat pump module through a heat pump water supply pipe. The water outlet end of the water source heat pump module is connected to the first clear water tank and the second clear water tank through a heat pump water return pipe. The third clear water tank is respectively connected to the water source heat pump module through a heat storage water supply pipe and a heat storage water return pipe.

[0014] Preferably, a first thermometer and a first flowmeter are provided on the heat pump water supply pipe. A second thermometer and a second flowmeter are provided on the heat pump water return pipe.

[0015] Preferably, a liquid level gauge is provided in each of the first clear water tank, the second clear water tank, and the third clear water tank. The clear water tank inlet channel is connected to an overflow drainage system through an overflow weir.[[ID=!9]]

[0016] A utilization method of a comprehensive sewage treatment and energy utilization system includes the following steps:

[0017] Step A: The sewage is introduced into the sewage treatment module, where it reacts to produce treated water and sludge, while the food waste is directly connected to the sludge treatment module;

[0018] Step B: The treated water is introduced into the reclaimed water reuse module for reclamation treatment, while the sludge is introduced into the sludge treatment module for co-treatment with the food waste;

[0019] Step C: After being treated by the reclaimed water reuse module, the reclaimed water is introduced into the pumped-storage module, the water-source heat pump module, and the miscellaneous water pipeline network for the utilization of reclaimed water energy;

[0020] Step D: The sludge and the food waste are co-anaerobically fermented in the sludge treatment module to produce biogas, which is then incorporated into the biogas cogeneration module and the natural gas pipeline network for the utilization of biogas energy;

[0021] Step E: The digested sludge and food waste are dehydrated, dried, and rendered harmless by the nutrient soil manufacturing device to produce organic nutrient soil for use in landscaping or soil remediation.

[0022] Preferably, the specific steps for the utilization of reclaimed water energy in Step C include;

[0023] C1, After being treated by the reclaimed water reuse module and meeting the reclaimed water standard, the treated water is divided into three parts for the utilization of reclaimed water resources;

[0024] C2, One part is supplied through the miscellaneous water pipeline network for municipal miscellaneous uses such as urban greening and road cleaning;

[0025] C3, One part is introduced into the water-source heat pump module, where, in combination with the water-source heat pump, the heat energy in the reclaimed water is extracted and incorporated into the heat pipeline network for heating and cooling;

[0026] C4, One part is used for pumped storage by the pumped-storage module. Through the conversion of high and low potential energy, the reclaimed water is converted into an energy storage medium, and in combination with the grid load demand, the water energy-electric energy interaction regulation is carried out. The generated electric energy is incorporated into the grid system to achieve the cascaded energy utilization of reclaimed water.

[0027] Preferably, in Step C4, the pumped-storage module operates in a peak-shaving mode with low load during the day and high load at night. During the day, the low-load water production of the reclaimed water plant is temporarily stored in the high-level regulating reservoir, and at night, through the linkage of the water distribution pump house, the high-load water production is processed and transported to the pipeline network. Driven by the conversion of high and low potential energy, the water turbine unit generates electricity, and the generated electric energy is regulated and incorporated into the grid in combination with the peak-valley demand of the grid to achieve the cascaded energy utilization of the potential energy-electric energy conversion and peak-shaving energy storage power generation of reclaimed water.

[0028] Preferably, the specific steps for the utilization of biogas energy in Step D include;

[0029] D1, The sludge and the food waste are introduced into the sludge treatment module;

[0030] D2 inputs anaerobic substances and ferments in a co-anaerobic manner to improve the biogas production rate;

[0031] D3 The biogas can be purified by a biogas purification device and then incorporated into the natural gas pipeline network;

[0032] D4 The biogas can also drive a biogas generator to achieve combined heat and power supply, and the waste heat from power generation is used to maintain the anaerobic digestion temperature and provide heating and cooling for the factory area.

[0033] In summary, the present invention has the following beneficial effects:

[0034] 1. By integrating various resource utilization technologies, the present invention organically combines modules such as sewage treatment and reclaimed water reuse, biogas combined heat and power generation, and nutrient soil manufacturing. The treated reclaimed water can be used for municipal miscellaneous uses, water source heat pump energy supply, and pumped storage power generation; the biogas generated by the co-anaerobic fermentation of sludge and food waste can be used for power generation, heating, or incorporated into the natural gas pipeline network; the digested sludge and food waste are processed into organic nutrient soil, fully exploiting the potential value of sewage, sludge, and food waste, achieving efficient resource utilization, and avoiding resource waste in traditional treatment modes.

[0035] 2. Using reclaimed water for pumped storage, the reclaimed water is converted into an energy storage medium through the conversion of high and low potential energy, and the interaction between water energy and electric energy is regulated in combination with the power grid load demand. The generated electric energy is incorporated into the power grid system, realizing the cascaded energy utilization of reclaimed water; on the other hand, the biogas generated by the co-anaerobic fermentation of sludge and food waste can drive a biogas generator to achieve combined heat and power supply, and the waste heat from power generation is used to maintain the anaerobic digestion temperature and provide heating and cooling for the factory area. This not only reduces the dependence on external electric energy, lowers the energy consumption of the sewage treatment plant, but also reduces the consumption of fossil energy by using renewable energy, thereby reducing carbon emissions and contributing to the goal of low carbon emissions.

[0036] 3. The present system adopts the co-anaerobic fermentation treatment method for sludge and food waste. In the sludge treatment module, the sludge and food waste ferment in an anaerobic environment, and the generated biogas is purified for natural gas supply or biogas power generation. The waste heat from power generation can be used to maintain the anaerobic digestion temperature and provide heating and cooling for the factory area. At the same time, the digested sludge and food waste are dehydrated, dried, and harmlessly treated by a nutrient soil manufacturing device to produce organic nutrient soil for landscaping or soil remediation. This not only avoids the environmental problems caused by landfilling and incineration, but also realizes the resource utilization of sludge, reduces environmental pollution, and meets the requirements of sustainable development.

[0037] 4. The system constructs a comprehensive energy utilization system with sewage treatment as the core, synchronously outputting reclaimed water, electric energy, heat energy, cold energy, and organic fertilizers, promoting the transformation of sewage treatment plants from "energy-consuming pollution treatment" to "energy-producing and energy-supplying", and through the collaborative development and comprehensive utilization of multiple resources, sewage treatment plants are no longer simply places for pollutant treatment, but have become producers of energy and resources, not only improving the economic benefits of sewage treatment plants, but also enhancing their sustainable development capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic diagram of the system of the present invention;

[0039] Figure 2 is a schematic diagram of the combined construction of reclaimed water reuse, water source heat pump utilization, and pumped storage in the present invention;

[0040] Figure 3 is a schematic diagram of the reclaimed water reuse module system of the present invention.

[0041] Description of the reference numerals in the drawings: 1. Sewage treatment module;

[0042] 2. Reclaimed water reuse module; 21. First clear water tank; 22. Second clear water tank; 23. Third clear water tank; 24. Water distribution pump house;

[0043] 3. Pumped storage module; 31. Reclaimed water pipe network; 32. High-level regulating reservoir; 33. Power station; 34. First valve; 35. Second valve; 36. Third valve;

[0044] 4. Water source heat pump module;

[0045] 5. Sludge treatment module;

[0046] 6. Biogas combined heat and power generation module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] In order to more clearly understand the above objects, features, and advantages of the present invention, the present invention will be further described below with reference to the drawings and embodiments.

[0048] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the limitations of the specific embodiments disclosed in the following specification. The present invention will be further described in detail below with reference to the drawings.

[0049] Embodiment 1: A comprehensive energy utilization system for sewage treatment, such as Figures 1 - 3As shown in the figure, it includes sewage, a sewage treatment module 1 that can decompose sewage into treated water and sludge, a reclaimed water reuse module 2, a kitchen waste delivery pipe, and a sludge treatment module 5. The water outlet area of the sewage treatment module 1 is connected to the reclaimed water reuse module 2. The reclaimed water reuse module 2 is respectively connected to a pumped-storage module 3 and a water source heat pump module 4. The sludge outlet area of the sewage treatment module 1 and the kitchen waste are both connected to a biogas cogeneration module 6 through the sludge treatment module 5. The sludge treatment module 5 is also externally connected to a biogas purification device and a nutrient soil manufacturing device. An intelligent inlet pump house is provided at the front end of the sewage treatment module 1, with an electric control valve interlocked with a flow meter inside, dynamically adjusting the inlet water flow according to the daytime / nighttime load difference; a sludge-water separation unit is arranged inside the module, and a pneumatic butterfly valve is installed on its sludge discharge pipeline and linked with a sludge concentration sensor to automatically start the sludge discharge mode and transport the sludge to the sludge treatment module 5;

[0050] A water distributor is provided at the outlet of the reclaimed water reuse module 2, equipped with a three-way proportional control valve, and the reclaimed water flow is distributed to path one, path two, and path three according to a set ratio through PLC control. Path one is connected to the miscellaneous water pipeline network through a check valve; path two enters the plate heat exchanger of the water source heat pump module 4 through a constant flow valve, and a temperature difference control valve is installed at the inlet and outlet of the heat exchanger to control the heat extraction efficiency; path three is connected to the pumped-storage module 3 through a liquid-controlled slow-closing check valve to prevent water hammer impact, and the liquid-controlled slow-closing check valve is the first valve 34 arranged between the reclaimed water pipeline network 31 and the water pipeline.

[0051] The biogas cogeneration module 6 is externally connected to the power grid and the heat grid. The pumped-storage module 3 is externally connected to the power grid, and the water source heat pump module 4 is externally connected to the heat grid.

[0052] The sludge treatment module 5 cooperates with the biogas cogeneration and nutrient soil manufacturing devices, and uses the sludge concentration sensor and the pneumatic butterfly valve for interlocked control to accurately discharge sludge and improve the anaerobic fermentation efficiency, so as to improve the methane purity of biogas and the comprehensive efficiency of cogeneration, and simultaneously produce high-value-added organic nutrient soil, forming a "sludge - energy - nutrient soil" closed loop.

[0053] Through the water distributor and three-way proportional control valve of the reclaimed water reuse module 2, the reclaimed water is dynamically distributed to the miscellaneous water pipeline network, the water source heat pump, and the pumped-storage module 3 as needed, achieving a reclaimed water reuse rate of ≥80% while supporting multiple energy conversion scenarios.

[0054] The pumped - storage module 3 includes a reclaimed water pipe network 31, a high - level storage pond 32, and a power station 33. The reclaimed water pipe network 31 is connected to the high - level storage pond 32 through a water conveyance pipeline. The high - level storage pond 32 is connected to the power station 33 and a water return pipeline through a water discharge pipeline. A first valve 34 is provided between the reclaimed water pipe network 31 and the water conveyance pipeline. A third valve 36 is provided between the water discharge pipeline and the power station 33. The water return pipeline is connected to the reclaimed water pipe network 31, and a second valve 35 is provided between the water return pipeline and the reclaimed water pipe network 31. The pumped - storage module 3 adopts a dual - mode switching design of energy storage during the day and power generation at night. During the day for energy storage, the high - level water tank inlet electric gate valve (the first valve 34) is opened, and the power generation branch stop valves (the second valve 35 and the third valve 36) are closed, and the reclaimed water is pressurized and stored. During the night for power generation, the first valve 34 is closed, the second valve 35 and the pressure - balancing valve (the third valve 36) are opened, and the impulse water turbine is driven by the height potential energy difference for power generation.

[0055] The water outlet end of the power station 33 and the water drainage end of the reclaimed water pipe network 31 are both externally connected to the river. The reclaimed water pipe network 31 is connected to the reclaimed water treatment plant, high - and - low storage ponds, the power station 33, users, etc., to meet the needs of reclaimed water users in the basin and the river water replenishment requirements. The water pressure elevation required at the most unfavorable point is denoted as H2, and the total loss from the high - level storage pond 32 to the most unfavorable point is denoted as h. The water volume in the high - level storage pond 32 can meet the total daily output of reclaimed water, and the lowest liquid level elevation is denoted as H1, and H1≥h + H2.

[0056] As Figure 3 As shown in the figure, the reclaimed water reuse module 2 includes a first clear water tank 21, a second clear water tank 22, a third clear water tank 23, and a water distribution pump house 24. The first clear water tank 21, the second clear water tank 22, and the third clear water tank 23 are all connected to the clear water tank inlet channel through inlet gates. The first clear water tank 21, the second clear water tank 22, and the third clear water tank 23 are all connected to the water distribution pump house 24 through outlet gates. The first clear water tank 21 and the second clear water tank 22 are both connected to the water source heat pump module 4 through heat pump water supply pipelines. The water outlet end of the water source heat pump module 4 is connected to the first clear water tank 21 and the second clear water tank 22 through heat pump water return pipelines. The third clear water tank 23 is connected to the water source heat pump module 4 through a heat storage water supply pipeline and a heat storage water return pipeline respectively. Inlet gates are provided for all 3 clear water tanks, denoted as the first inlet gate, the second inlet gate, and the third inlet gate; the same applies to the outlet gates; the water source heat pump module 4 is the heat station.

[0057] A first thermometer and a first flowmeter are provided on the heat pump water supply pipe, a second thermometer and a second flowmeter are provided on the heat pump water return pipe. A fourth valve, a sixth valve, a first flowmeter (with the flow denoted as q1), and a first thermometer (with the temperature denoted as t1) are arranged on the heat pump water supply pipe; a fifth valve, a seventh valve, a second flowmeter (with the flow denoted as q2), and a second thermometer (with the temperature denoted as t2) are arranged on the heat pump water return pipe. An eighth valve and a ninth valve are respectively arranged on the heat storage water supply pipe and the water return pipe. The heat that can be provided for the heat pump system is denoted as Q, and Q = C×ρ×q1×(t1 - t2).

[0058] Level gauges are provided in the first clear water tank 21, the second clear water tank 22, and the third clear water tank 23. The water inlet channel of the clear water tank is connected to the overflow water drainage system through an overflow weir, and the water distribution pump house 24 is connected to the suction well.

[0059] Heating (cooling) season: The volume of the third clear water tank 23 as the heat storage water tank needs to be greater than W4. The first clear water tank 21 and the second clear water tank 22 are respectively the regulating reservoirs for municipal reclaimed water for miscellaneous uses and the reclaimed water for the heat station, and the tank volumes need to be greater than W2 and W3 respectively. If the first clear water tank 21 stores municipal water and the second clear water tank 22 stores the heat pump water supply, the opening and closing conditions of the valves are as follows:

[0060] The first and third inlet gates are closed, and the second inlet gate is open;

[0061] The first outlet gate is open, and the second and third outlet gates are closed;

[0062] The fourth valve and the seventh valve are closed, and the fifth valve and the sixth valve are open;

[0063] The eighth valve and the ninth valve are open.

[0064] At this time, the reclaimed water first enters the second clear water tank 22 to ensure sufficient water intake for the heat pump system; the heat pump return water enters the first clear water tank 21, which can meet the water replenishment requirements of the first clear water tank 21. All the municipal reclaimed water is taken from the first clear water tank 21, which can ensure that the heat pump does not take the return water of the heat pump system; the third clear water tank 23 stores hot water for the heat pump system.

[0065] When the liquid level of the second clear water tank 22 reaches the highest value, the first inlet gate is opened, and the reclaimed water can enter the first clear water tank 21 and the second clear water tank 22 simultaneously. When the water level continues to rise, it can enter the overflow water drainage system through the overflow weir and be discharged.

[0066] Non - heating (cooling) season: When the first inlet gate, the second inlet gate, and the third inlet gate are open, the first outlet gate, the second outlet gate, and the third outlet gate are open, and the fourth, fifth, sixth, seventh, eighth, and ninth valves are all closed, each clear water tank can be used for the regulation of municipal reclaimed water.

[0067] Each pool can operate independently. Therefore, it can also be specifically shut down for maintenance according to the operation needs.

[0068] Example 2: A utilization method of a comprehensive energy utilization system for sewage treatment, as Figures 1 - 3 shown, includes the following steps:

[0069] Step A: The sewage is introduced into the sewage treatment module 1, and it reacts to produce treated water and sludge, while the food waste is directly connected to the sludge treatment module 5;

[0070] Step B: The treated water is introduced into the reclaimed water reuse module 2 for reclamation treatment, while the sludge is introduced into the sludge treatment module 5 for co-treatment with the food waste;

[0071] The food waste is directly connected to the sludge treatment module 5 through a special conveying pipeline, avoiding cross-contamination, and is mixed with the sludge generated by the sewage treatment module 1 to form a co-digestion system with a high organic matter content. The easily degradable characteristics of the food waste (including oils and fats, carbohydrates, etc.) are complementary to the microbial enrichment characteristics of the sludge, significantly improving the anaerobic fermentation gas production efficiency and providing a stable fuel for subsequent combined heat and power generation.

[0072] Step C: After being treated by the reclaimed water reuse module 2, the reclaimed water is introduced into the pumped-storage module 3, the water source heat pump module 4 and the miscellaneous water pipeline network for reclaimed water energy utilization;

[0073] C1, The treated water is treated by the reclaimed water reuse module 2. After reaching the reclaimed water standard, it is divided into three parts for the utilization of reclaimed water resources;

[0074] Maximize the value of reclaimed water.

[0075] C2, One part is supplied to municipal miscellaneous uses such as urban greening and road cleaning through the miscellaneous water pipeline network;

[0076] After being stabilized by the check valve, the reclaimed water is directly connected to low-quality water use scenarios such as urban greening and road cleaning, relieving the municipal water supply pressure, reducing the demand for fresh water resources, and also reducing the urban water treatment cost.

[0077] C3, One part is introduced into the water source heat pump module 4. Combining with the water source heat pump, the heat energy in the reclaimed water is extracted and incorporated into the heat pipe network for heating and cooling;

[0078] C4, One part is pumped and stored through the pumped-storage module 3. The reclaimed water is converted into an energy storage medium through the conversion of high and low potential energy, and combined with the grid load demand for water-energy-electricity interaction regulation. The generated electricity is incorporated into the grid system to achieve the cascade energy utilization of reclaimed water;

[0079] In this module, recycled water is used as an energy storage medium to store energy through the conversion of high and low potential energies. When the grid load is low, the pumped storage module 3 can use electricity to pump water from a low level to a high level for storage; when the grid load is high, it can generate electricity by releasing the water stored at a high level to meet the load requirements of the grid.

[0080] The heat-electricity-water coupling energy supply, the water source heat pump module 4 and the biogas cogeneration module 6 form "heat network complementarity"; the pumped storage module 3 and the biogas power generation are connected to the grid to coordinate and participate in power peak regulation, thereby improving the energy self-sufficiency rate of the entire plant. The energy storage efficiency of the pumped storage module 3 is effectively improved, and it can replace the coal-fired peak-shaving unit.

[0081] In step C4, the pumped storage module 3 operates in a staggered mode with low load during the day and high load at night. During the day, the low-load water produced by the reclaimed water plant is temporarily stored in the highland regulating storage tank 32. At night, the high-load water is processed through the water distribution pump room 24 and transported to the pipeline network. Based on the conversion of high and low potential energy, the turbine unit is driven to generate electricity. The generated electricity is regulated and connected to the grid in combination with the peak and valley demand of the power grid, realizing the cascade energy utilization of recycled water potential energy-electricity conversion and peak-shifting energy storage power generation.

[0082] The maximum capacity of the highland regulating reservoir 32 can be the total daily water volume. The water volume that cannot be absorbed by the recycled water network 31 can be operated in pumping power generation mode. The lowest liquid level of the pool can meet the pressure demand at the most unfavorable point of the recycled water network 31. In addition to the recycled water network 31, the highland regulating reservoir 32 and the power station 33, the pumped storage module 3 also includes a front-of-plant regulating reservoir, a clear water tank and a water distribution pump room 24, and adopts a staggered operation mode with low load during the day and high load at night.

[0083] The regulating reservoir in front of the plant is used to store the daytime peak sewage; the clear water tank is used to store the recycled water produced by the recycled water plant at low load during the day; the water distribution pump room does not operate for 24 days and operates entirely at night, with the lifting capacity to meet the total flow of the whole day; the power plant has the capacity to use all the water for hydropower generation and is connected to the municipal power grid.

[0084] The reclaimed water plant operates at low load during the day, with excess wastewater temporarily stored in the plant's front-of-house regulating and storage tanks, and the produced reclaimed water temporarily stored in the clear water tank. At night, the plant operates at high load, treating all incoming water and wastewater in the regulating and storage tanks. The produced reclaimed water, along with the reclaimed water stored during the day, is then delivered to the water distribution network via the water distribution pumphouse 24. The water distribution network is supplied entirely by the highland regulating and storage tank 32 during the day. At night, the highland regulating and storage tank 32 stores the reclaimed water, which is then supplied to the water distribution network during the day. Excess reclaimed water flows to the power station 33, which supplies power to the municipal power grid, achieving peak-shaving energy storage and power generation.

[0085] Step D: The sludge and food waste are co-anaerobically fermented in the sludge treatment module 5 to produce biogas, which is then incorporated into the biogas combined heat and power generation module 6 and the natural gas pipeline network for biogas energy utilization;

[0086] The specific steps of biogas energy utilization in Step D are as follows;

[0087] D1, The sludge and food waste are introduced into the sludge treatment module 5;

[0088] In this module, the sludge and food waste are evenly mixed to prepare for the subsequent anaerobic fermentation process.

[0089] D2, Input anaerobic conditions and carry out co-anaerobic fermentation to improve the biogas production rate;

[0090] Through the action of anaerobic microorganisms, organic matter is decomposed into biogas and other biological substances. The co-anaerobic fermentation process can improve the biogas production rate because the different components in the sludge and food waste can complement each other and promote the activity of microorganisms.

[0091] D3, The biogas can be purified by a biogas purification device and then incorporated into the natural gas pipeline network;

[0092] The generated biogas can be purified by a biogas purification device to remove impurities and carbon dioxide in it and improve the purity of methane; the purified biogas can be incorporated into the natural gas pipeline network and used as a clean energy source.

[0093] D4, The biogas can also drive a biogas generator to achieve combined heat and power supply, and the waste heat from power generation is used to maintain the anaerobic digestion temperature and provide heating and cooling for the plant area.

[0094] Step E: The digested sludge and food waste are dehydrated, dried, and harmlessly treated by a nutrient soil manufacturing device to produce organic nutrient soil for landscaping or soil remediation.

[0095] The mixture of sludge and food waste after anaerobic fermentation needs to be dehydrated to remove the water in it. The dehydrated material is further dried to reduce its volume and weight for subsequent treatment and transportation. During the drying process, harmless treatment can also be carried out to ensure the safety and environmental protection of the final product, and organic nutrient soil is produced.

[0096] The biogas energy supply drives the operation of the sludge treatment module 5, and the nutrient soil feeds back to ecological restoration, forming a zero-waste mode of "treating waste with waste and energy-fertilizer cycle"; completely solving the problems of high disposal costs and high risk of secondary pollution of sludge and food waste.

[0097] The parts and equipment all adopt conventional models in the existing technology, and the circuit connection adopts the conventional connection method in the existing technology, which will not be elaborated here. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0098] As described above, it is only the preferred embodiment of the present invention, and it does not limit the present invention in other forms. Any person skilled in the art may use the technical content disclosed above to make changes or modifications into equivalent embodiments with equivalent changes and apply them to other fields. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification or equivalent change made to the above embodiments based on the technical essence of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. An integrated energy utilization system for sewage treatment, characterized in that: It includes sewage, a sewage treatment module (1) that can decompose sewage into treated water and sludge, a reclaimed water reuse module (2), a kitchen waste delivery pipe, and a sludge treatment module (5). The water outlet area of the sewage treatment module (1) is connected to the reclaimed water reuse module (2). The reclaimed water reuse module (2) is respectively connected to a pumped-storage energy module (3) and a water source heat pump module (4). The sludge outlet area of the sewage treatment module (1) and the kitchen waste are both connected to a biogas combined heat and power module (6) through the sludge treatment module (5). The sludge treatment module (5) is also externally connected to a biogas purification device and a nutrient soil manufacturing device; The biogas combined heat and power module (6) is externally connected to an electric power grid and a heat pipeline network. The pumped-storage energy module (3) is externally connected to an electric power grid. The water source heat pump module (4) is externally connected to a heat pipeline network.

2. The integrated energy utilization system for sewage treatment according to claim 1, wherein: The pumped-storage energy module (3) includes a reclaimed water pipeline network (31), a high-level storage pool (32), and a power station (33). The reclaimed water pipeline network (31) is connected to the high-level storage pool (32) through a water delivery pipeline. The high-level storage pool (32) is connected to the power station (33) and a water return pipeline through a water outlet pipeline. A first valve (34) is provided between the reclaimed water pipeline network (31) and the water delivery pipeline. A third valve (36) is provided between the water outlet pipeline and the power station (33). The water return pipeline is connected to the reclaimed water pipeline network (31), and a second valve (35) is provided between the water return pipeline and the reclaimed water pipeline network (31).

3. The integrated energy utilization system for sewage treatment according to claim 2, wherein: The water outlet end of the power station (33) and the drainage end of the reclaimed water pipeline network (31) are both externally connected to a river.

4. The integrated energy utilization system for sewage treatment according to claim 1, wherein: The reclaimed water reuse module (2) includes a first clear water tank (21), a second clear water tank (22), a third clear water tank (23), and a water distribution pump house (24). The first clear water tank (21), the second clear water tank (22), and the third clear water tank (23) are all connected to a clear water tank water inlet channel through a water inlet sluice. The first clear water tank (21), the second clear water tank (22), and the third clear water tank (23) are all connected to the water distribution pump house (24) through a water outlet sluice. The first clear water tank (21) and the second clear water tank (22) are both connected to the water source heat pump module (4) through a heat pump water supply pipe. The water outlet end of the water source heat pump module (4) is connected to the first clear water tank (21) and the second clear water tank (22) through a heat pump water return pipe. The third clear water tank (23) is respectively connected to the water source heat pump module (4) through a heat storage water supply pipe and a heat storage water return pipe.

5. The integrated energy utilization system for sewage treatment according to claim 4, wherein: A first thermometer and a first flowmeter are provided on the heat pump water supply pipe. A second thermometer and a second flowmeter are provided on the heat pump water return pipe.

6. The integrated energy utilization system for sewage treatment according to claim 4, characterized in that: Level gauges are provided in the first clear water tank (21), the second clear water tank (22), and the third clear water tank (23). The clear water tank water inlet channel is connected to an overflow drainage system through an overflow weir.

7. A utilization method of a comprehensive energy utilization system for sewage treatment, characterized in that, For energy utilization of the comprehensive sewage treatment energy utilization system described in claim 3, it includes the following steps: Step A: The sewage is introduced into the sewage treatment module (1) and reacted into treated water and sludge, while the kitchen waste is directly connected to the sludge treatment module (5); Step B: The treated water is introduced into the reclaimed water reuse module (2) for reclamation treatment, while the sludge is introduced into the sludge treatment module (5) for co-treatment with food waste. Step C: After being treated by the reclaimed water reuse module (2), the reclaimed water is introduced into the pumped-storage module (3), the water source heat pump module (4), and the miscellaneous water supply pipeline network for reclaimed water energy utilization. Step D: The sludge and food waste are co-anaerobically fermented in the sludge treatment module (5) to produce biogas, which is then incorporated into the biogas combined heat and power module (6) and the natural gas pipeline network for biogas energy utilization. Step E: The digested sludge and food waste are dehydrated, dried, and rendered harmless by the nutrient soil manufacturing device to produce organic nutrient soil for landscaping or soil remediation.

8. The utilization method of an integrated energy utilization system for sewage treatment according to claim 7, characterized in that: The specific steps for reclaimed water energy utilization in Step C are as follows: C1, After the treated water is treated by the reclaimed water reuse module (2) and meets the reclaimed water standard, it is divided into three parts for the utilization of reclaimed water resources. C2, One part is supplied through the miscellaneous water supply pipeline network for municipal miscellaneous uses such as urban greening and road cleaning. C3, One part is introduced into the water source heat pump module (4). Combining with the water source heat pump, the heat energy in the reclaimed water is extracted and incorporated into the heat pipeline network for heating and cooling. C4, One part is used for pumped storage through the pumped-storage module (3). Through the conversion of high and low potential energy, the reclaimed water is converted into an energy storage medium. Combining with the grid load demand, the water energy-electric energy interaction regulation is carried out, and the generated electric energy is incorporated into the grid system to achieve the cascaded energy utilization of reclaimed water.

9. The utilization method of a comprehensive energy utilization system for sewage treatment according to claim 8, characterized in that: In Step C4, the pumped-storage module (3) operates in a peak-shaving mode with low load during the day and high load at night. During the day, the low-load water production of the reclaimed water treatment plant is temporarily stored in the high-level regulating reservoir (32). At night, through the linkage of the water distribution pump house (24), the high-load water production is processed and transported to the pipeline network. Driven by the conversion of high and low potential energy, the water turbine generator sets generate electricity, and the generated electric energy is regulated and incorporated into the grid in combination with the peak-valley demand of the grid, realizing the cascaded energy utilization of the conversion of reclaimed water potential energy-electric energy and peak-shaving energy storage power generation.

10. The utilization method of an integrated energy utilization system for sewage treatment according to claim 6, characterized in that: The specific steps for biogas energy utilization in Step D are as follows: D1, The sludge and food waste are introduced into the sludge treatment module (5). D2, Anaerobic conditions are input, and co-anaerobic fermentation is carried out to improve the biogas production rate. D3, The biogas can be purified by the biogas purification device and then incorporated into the natural gas pipeline network. D4, The biogas can also drive the biogas generator to achieve combined heat and power supply, and the waste heat from power generation is used to maintain the anaerobic digestion temperature and provide heating and cooling for the plant area.

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