System for recycling waste heat of sewage plant and heating aeration air
Through the waste heat recovery system of the sewage plant, heat pump technology is used to heat aeration air, which solves the problem that the low sewage temperature in cold northern areas affects biochemical treatment, and achieves stable temperature increase in sewage temperature and improves microbial metabolic efficiency, achieving stable sewage emissions and standards Carbon reduction goal.
Patent Information
- Application Number
- CN202421060811.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-15
- Publication Date
- 2025-01-17
- Estimated Expiration
- 2034-05-15
AI Technical Summary
In cold northern areas, when the inlet water temperature of the sewage plant is lower than 12℃, the metabolic efficiency of the biochemical treatment system is affected, making it difficult for the sewage temperature to maintain a stable temperature range of discharge standards, affecting the sewage purification effect.
The waste heat recovery system of the sewage plant is adopted to transfer the waste heat of the sewage to the aeration air through heat pump technology, heat the biochemical treatment process, and increase the sewage temperature, including heat pump evaporator, compressor, heat pump condenser and aeration air heating device, forming a circuit to Achieve effective heat transfer.
It effectively increases the sewage temperature in the biochemical treatment system in cold areas, enhances the metabolic effect of microorganisms, ensures stable and standard emissions of sewage, and realizes the alternative utilization of fossil energy and reduces carbon emissions.
Smart Images
Figure CN222362015U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of sewage treatment, and in particular relates to a system for recovering waste heat from a sewage plant for aeration air heating. Background Art
[0002] Urban sewage treatment plants mainly rely on the metabolism of microorganisms to purify sewage, and water temperature has a great impact on the purification effect. When the water temperature is lower than 12°C, the metabolic behavior of nitrifying bacteria, the main functional bacteria for removing ammonia nitrogen in sewage, almost stops. Maintaining the biochemical system at a temperature above 12°C or higher is a necessary condition for the stable discharge of sewage that meets the standards.
[0003] In the cold northern regions, when the temperature drops to -20℃ in winter, the inlet water temperature of the sewage treatment plant will drop to around 7℃, the temperature of the biochemical pool will be even lower, and ice may even form on the surface of the secondary sedimentation tank.
[0004] In the existing technology, sewage treatment plants in cold northern regions set up pretreatment and deep treatment units in workshops other than large tanks such as biochemical tanks and secondary sedimentation tanks to minimize heat loss. However, when the inlet water temperature is very low, simply reducing the heat loss of sewage still cannot ensure that the biochemical tank is within a reasonable temperature range. If effective measures can be taken to solve or alleviate the impact of low sewage temperature in extreme weather, and the sewage temperature in the biochemical treatment process is maintained at above 12°C or higher, it can well ensure that the sewage is discharged stably and meets the standards. Utility Model Content
[0005] The utility model aims to provide a system for recovering waste heat from a sewage plant for aeration air heating, so as to solve or alleviate the influence of too low sewage temperature on the metabolic efficiency of a biochemical treatment system.
[0006] The technical solution adopted by the utility model is a system for recovering waste heat from a sewage plant for aeration air heating, comprising a pretreatment system for sedimentation and filtration of sewage, a biochemical treatment system for decomposing organic matter, a deep treatment system for removing suspended matter and microorganisms, and a sewage source heat pump system and an aeration air heating device arranged between the deep treatment system and the biochemical treatment system.
[0007] The sewage source heat pump system comprises a heat pump evaporator, a compressor, a heat pump condenser, and a heat pump expansion valve which are sequentially connected to form a loop; the heat pump evaporator is connected to the outlet pipe of the deep treatment system;
[0008] The aeration air heating device includes a circulating water pipeline, a heating coil, an air intake pipe, and an aeration fan. One end of the circulating water pipeline is arranged on the heat pump condenser, and the other end is connected to the heating coil. The circulating water pipeline and the heating coil form a closed loop. The air intake pipe and the aeration fan are respectively arranged on both sides of the heating coil. The aeration fan is connected to the biochemical treatment system.
[0009] Preferably, the heat pump evaporator is connected to the outlet pipe of the deep treatment system through a sewage intake pipe and a sewage return pipe, and a sewage intake pump is provided on the sewage intake pipe.
[0010] Preferably, a circulating water pump is provided on the circulating water pipeline.
[0011] Preferably, the pretreatment system includes a coarse screen and a lift pump room, a fine screen and a grit chamber connected in sequence. The coarse screen and the lift pump room are used to intercept larger solid impurities in the water and lift the sewage to a subsequent treatment unit. The fine screen and the grit chamber further remove suspended solids and large particulate matter in the sewage through filtration and sedimentation.
[0012] Preferably, the biochemical treatment system comprises an aeration tank, which is used to decompose organic matter in the sewage.
[0013] Preferably, the deep treatment system comprises a secondary sedimentation tank and a disinfection tank which are connected in sequence, the secondary sedimentation tank is used for separating sludge from sewage, and the disinfection tank is used for disinfecting water quality.
[0014] The beneficial effects of the utility model are:
[0015] The utility model utilizes the waste heat of sewage to heat the aeration air and transfers the heat to the biochemical treatment process, which can effectively increase the sewage temperature of the biochemical treatment system in cold areas, improve the metabolism of microorganisms, complete sewage purification, and ensure that the sewage is stably discharged up to the standard.
[0016] Without using fossil energy, we can achieve the synergistic effect of reducing pollution and carbon emissions by utilizing waste heat and heating sewage. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the system principle for recovering waste heat from a sewage treatment plant for aeration air heating.
[0018] In the figure: 11, coarse screen and lifting pump room; 12, fine screen; 13, grit tank; 14, aeration tank; 15, secondary sedimentation tank; 16, disinfection tank; 20, aeration air heating device; 21, heating coil; 22, aeration fan; 23, air intake duct; 24, air supply duct; 25, circulating water pump; 26, circulating water pipeline; 30, sewage source heat pump system; 31, compressor; 32, heat pump evaporator; 33, heat pump condenser; 34, heat pump expansion valve; 35, sewage intake pipeline; 36, sewage intake pump; 37, sewage return pipeline; 38, valve body. DETAILED DESCRIPTION
[0019] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.
[0020] Example 1
[0021] The waste heat recovery system of a sewage treatment plant for aeration air heating of the utility model comprises a pretreatment system for sedimentation and filtration of sewage, a biochemical treatment system for decomposing organic matter, a deep treatment system for removing suspended matter and microorganisms, and a sewage source heat pump system 30 and an aeration air heating device 20 arranged between the deep treatment system and the biochemical treatment system.
[0022] Example 2
[0023] like Figure 1 As shown, based on Example 1, the pretreatment system of this embodiment includes a coarse screen and a lifting pump room 11, a fine screen 12 and a grit chamber 13 connected in sequence by pipelines. The coarse screen and the lifting pump room 11 are used to intercept larger solid impurities in the water and lift the sewage to the subsequent treatment unit, and the fine screen 12 and the grit chamber 13 further remove suspended solids and large particles in the sewage through filtration and sedimentation.
[0024] The biochemical treatment system includes an aeration tank 14, which utilizes aerobic microorganisms in water to decompose organic matter in the sewage, thereby purifying the water quality.
[0025] The deep treatment system includes a secondary sedimentation tank 15 and a disinfection tank 16 which are connected in sequence by pipelines. The secondary sedimentation tank 15 is used to separate sludge from sewage to ensure that the clarified water quality meets the discharge standard. The disinfection tank 16 is used to disinfect the water quality to kill pathogens and microorganisms that may exist in the water and ensure water quality safety.
[0026] The sewage source heat pump system 30 includes a compressor 31, a heat pump evaporator 32, a heat pump condenser 33, and a heat pump expansion valve 34. The heat pump evaporator 32, the compressor 31, the heat pump condenser 33, and the heat pump expansion valve 34 are sequentially connected through pipelines to form a heat exchange loop.
[0027] The heat pump evaporator 32 is connected to the deep treatment system through the sewage intake pipe 35 and the sewage return pipe 37. The sewage intake pipe 35 and the sewage return pipe 37 are both branch pipes on the outlet pipe of the disinfection tank 16. The sewage intake pipe 35 is provided with a sewage intake pump 36. The sewage intake pump 36 draws sewage tail water to the heat pump evaporator 32. The sewage after absorbing the residual heat energy by the heat pump evaporator 32 is discharged back to the outlet pipe of the disinfection tank 16 through the sewage return pipe 37, realizing the transfer of low-level heat energy to high-level heat energy. A valve body 38 is provided on the pipe between the connection between the sewage intake pipe 35 and the outlet pipe of the disinfection tank 16 and the connection between the sewage return pipe 37 and the outlet pipe of the disinfection tank 16. The valve body 38 is used to change the flow direction of the sewage. When the temperature is too low and heat exchange is required, it is in a closed state and can prevent the sewage after heat exchange from flowing back.
[0028] The heat pump evaporator 32 is used to absorb the heat of the low-temperature heat source in the sewage. In the heat pump evaporator 32, the refrigerant changes from liquid to gas, and absorbs the surrounding heat in this process, thereby achieving the purpose of cooling the surrounding environment.
[0029] The heat pump condenser 33 is used to output heat. In the heat pump condenser 33, the refrigerant vapor releases heat and condenses into a liquid state. The heat released in this process is used for heating purposes.
[0030] A compressor 31 is provided on the heat pump evaporator outlet pipe between the heat pump evaporator 32 and the heat pump condenser 33. The compressor 31 is used to compress the low-pressure gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant. The high-temperature and high-pressure refrigerant then enters the heat pump condenser 33, exchanges heat with the aeration air heating device 20, and the refrigerant releases heat and condenses into a liquid.
[0031] A heat pump expansion valve 34 is provided on the heat pump condenser outlet pipe between the heat pump evaporator 32 and the heat pump condenser 33 . The heat pump expansion valve 34 is used for throttling and reducing pressure.
[0032] The working principle of the sewage source heat pump system 30 is as follows: the compressor 31 compresses the refrigerant into high-temperature and high-pressure vapor, and then sends it to the heat pump condenser 33. In the heat pump condenser 33, the refrigerant liquefies after heat exchange and heat release, and then passes through the heat pump expansion valve 34 to reduce pressure and expand, and enters the heat pump evaporator 32. In the heat pump evaporator 32, the refrigerant absorbs the heat of the low-temperature heat source and evaporates, and then is sucked into the compressor 31 again, completing a cycle.
[0033] The aeration air heating device 20 includes a heating coil 21 , an aeration fan 22 , an air intake pipe 23 , an air supply pipe 24 , a circulating water pump 25 , and a circulating water pipe 26 .
[0034] One end of the circulating water pipe 26 is arranged on the heat pump condenser 33, and the other end is connected to the heating coil 21. The circulating water pipe 26 and the heating coil 21 form a closed loop. The circulating water pump 25 is arranged on the return water section of the circulating water pipe 26. The high-temperature steam is converted into liquid through the heat pump condenser 33, and a large amount of heat energy is released at the same time. The circulating water in the circulating water pipe 26 absorbs the heat energy and the temperature rises. After that, the circulating water enters the heating coil 21 for cooling and heat dissipation, and then flows back to the circulating water pipe 26 under the action of the circulating water pump 25, so as to realize the uninterrupted cycle of the heat exchange process.
[0035] The air intake duct 23 and the aeration fan 22 are respectively arranged on both sides of the heating coil 21. The air in the air intake duct 23 flows through the heating coil 21 for heat exchange and then enters the aeration fan 22. The aeration fan 22 is connected to the aeration tank through the air supply duct 24.
[0036] The aeration fan 22 is a device used to force air or other gases into water or liquid, and its main purpose is to increase the dissolved oxygen in the water to meet the oxygen demand of aerobic organisms.
[0037] Under the action of the sewage source heat pump system 30, the heating coil 21 can heat the fresh air to about 30°C. After the fresh air enters the aeration tank, the sewage can be heated from 7°C to 12-14°C.
[0038] The waste heat recovery system for aeration air heating in the sewage treatment plant of the present invention extracts waste heat energy from sewage through a heat pump evaporator 32 and releases it through a heat pump condenser 33, thereby realizing waste heat energy recovery and utilization.
[0039] Components and structures not described in detail in the embodiments are well-known components and common structures or common means in the industry and are not described one by one here.
Claims
1. A system for recovering waste heat from a sewage treatment plant for aeration air heating, characterized in that: It comprises a pretreatment system for settling and filtering sewage, a biochemical treatment system for decomposing organic matter, a deep treatment system for removing suspended matter and microorganisms, and a sewage source heat pump system (30) and an aeration air heating device (20) arranged between the deep treatment system and the biochemical treatment system. The sewage source heat pump system (30) comprises a heat pump evaporator (32), a compressor (31), a heat pump condenser (33), and a heat pump expansion valve (34) which are sequentially connected to form a loop; the heat pump evaporator (32) is connected to the water outlet pipe of the deep treatment system; The aeration air heating device (20) comprises a circulating water pipeline (26), a heating coil (21), an air intake pipe (23), and an aeration fan (22); one end of the circulating water pipeline (26) is arranged on the heat pump condenser (33), and the other end is connected to the heating coil (21); the circulating water pipeline (26) and the heating coil (21) form a closed loop; the air intake pipe (23) and the aeration fan (22) are respectively arranged on both sides of the heating coil (21); and the aeration fan (22) is connected to the biochemical treatment system.
2. The system for recovering waste heat from a sewage treatment plant for aeration air heating according to claim 1 is characterized in that: The heat pump evaporator (32) is connected to the outlet pipe of the deep treatment system via a sewage intake pipe (35) and a sewage return pipe (37), and a sewage intake pump (36) is provided on the sewage intake pipe (35).
3. The system for recovering waste heat from a sewage treatment plant for aeration air heating according to claim 1 is characterized in that: A circulating water pump (25) is provided on the circulating water pipeline (26).
4. The system for recovering waste heat from a sewage treatment plant for aeration air heating according to claim 1, characterized in that: The pretreatment system comprises a coarse screen and a lifting pump room (11), a fine screen (12) and a grit chamber (13) which are connected in sequence. The coarse screen and the lifting pump room (11) are used to intercept larger solid impurities in the water and lift the sewage to a subsequent treatment unit. The fine screen (12) and the grit chamber (13) further remove suspended solids and large particles in the sewage through filtration and sedimentation.
5. The system for recovering waste heat from a sewage treatment plant for aeration air heating according to claim 1, characterized in that: The biochemical treatment system comprises an aeration tank (14), and the aeration tank (14) is used to decompose organic matter in sewage.
6. The system for recovering waste heat from a sewage treatment plant for aeration air heating according to claim 1, characterized in that: The deep treatment system comprises a secondary sedimentation tank (15) and a disinfection tank (16) which are connected in sequence. The secondary sedimentation tank (15) is used for separating sludge from sewage, and the disinfection tank (16) is used for disinfecting water.