A cold and heat source supply system based on coupling of reclaimed water reuse and water source heat pump

Abstract

This invention discloses a cold and heat source supply system based on greywater reuse and water source heat pump coupling, relating to the fields of building energy conservation and wastewater waste heat recovery and utilization. Addressing the problems of unrecovered low-grade waste heat, unreused miscellaneous wastewater, and isolated energy supply subsystems in existing student dormitories, this system includes a wastewater collection pipe, a greywater filtration unit, a water source heat pump unit, a wastewater deep treatment unit, a control center, and outdoor temperature and humidity transmitters. Wastewater from showering, washing, and laundry in the dormitories enters the water source heat pump unit after primary filtration and greywater filtration. Waste heat is extracted for heating in winter and used for cooling in summer. After heat exchange, the wastewater undergoes deep treatment including sedimentation, coagulation, biological oxidation, and disinfection, and is reused for toilet flushing and landscaping after meeting standards. The control center switches between winter and summer operating conditions based on outdoor temperature and implements online water quality monitoring, bypass protection, backwashing, and meteorological feedforward regulation. This invention can recover low-grade waste heat and achieve cascaded greywater reuse, reducing building energy and water consumption.

Description

Technical Field

[0001] This invention relates to the field of building energy conservation and wastewater waste heat recovery and utilization technology, specifically to a system that uses domestic wastewater from student dormitories as a heat source, and after greywater treatment, couples it with a water source heat pump unit to achieve cooling, heating and cascade utilization of water resources. Background Technology

[0002] As one of the most widely distributed and frequently used residential buildings on campus, student apartments account for a considerable proportion of the overall operating costs of the campus in terms of energy and resource consumption.

[0003] I. Current Status of Energy and Water Consumption in Student Dormitories Regarding energy supply, most university dormitories in my country operate under a seasonal, system-specific model, with centralized municipal heating in winter and split-system air conditioning in summer. Winter heating is provided by the city's heating network, with indoor heating typically achieved through radiators or underfloor heating; the heat source is singular and non-adjustable. Summer cooling relies on decentralized split-system air conditioners, each room operating independently. For domestic hot water supply, most universities use a centralized, timed supply method, with heat sources primarily consisting of gas boilers, electric boilers, or air-source heat pump units.

[0004] In terms of water use and drainage, student dormitories generate a large amount of bathing wastewater and daily washing wastewater every day. Among them, the temperature of the bathing wastewater discharge is usually between 30 and 35°C, and the flow is concentrated and distinctly time-bound. Currently, this wastewater is generally treated by being directly discharged into the building's drainage network without any heat recovery treatment, and eventually flows into the municipal sewage system.

[0005] II. Objective shortcomings of the existing technological system 1. Low-grade heat energy is not effectively recovered and utilized. The temperature of shower wastewater discharge is significantly higher than the ambient temperature (especially during the non-heating season), and there is a usable temperature difference between it and the return water temperature for winter heating. Waste heat recovery technologies, such as water source heat pumps, can theoretically extract this low-grade heat energy for preheating domestic water supply or supplementing heating. However, the existing water supply and drainage and HVAC systems in student dormitories are designed independently, without reserved interfaces for wastewater heat recovery, resulting in a large amount of recoverable heat energy being directly lost with the wastewater. Meanwhile, the temperature of shower wastewater in summer is lower than the outdoor air temperature, and its inherent "cooling capacity" has the potential to assist air conditioning cooling, but the existing system architecture cannot achieve both heat and cold recovery.

[0006] 2. High-quality non-potable water has not been reused in a graded manner. The wastewater from student dormitories, specifically from bathing and washing facilities, is typically high-quality greywater, with relatively low organic matter and suspended solids content. After treatment using membrane therapy or biological contact oxidation, the water quality is perfectly suitable for non-potable uses such as toilet flushing, watering green spaces, and landscape irrigation. However, most school dormitories currently lack adequate greywater treatment facilities or are limited by existing building conditions to install independent reuse systems. This results in a significant amount of reusable water being downgraded and discharged, increasing the burden on municipal water supply and the operational pressure on wastewater treatment plants.

[0007] 3. Lack of coordinated coupling mechanism between energy supply subsystems. The three major energy-consuming subsystems—winter heating, summer cooling, and year-round domestic hot water preparation—operate independently, lacking a unified energy dispatching and tiered utilization strategy. On the one hand, heat from bathing wastewater cannot be allocated across seasons and systems to the heating or hot water preheating stages; on the other hand, some waste heat from the winter heating system and summer air conditioning condensation heat are also not effectively captured. The entire building energy system exhibits an extensive operation characterized by "inefficient use of high-grade energy and massive waste of low-grade energy," indicating significant room for improvement in overall energy utilization efficiency.

[0008] In summary, existing university student dormitories generally suffer from technical deficiencies in their energy and water systems, such as the lack of recovery of low-grade waste heat, the lack of reuse of miscellaneous wastewater, and the isolation of energy supply subsystems. There is an urgent need to develop a comprehensive solution that can coordinate waste heat recovery, greywater reuse, and multi-energy complementarity to improve the overall energy and water resource utilization efficiency of university student dormitories. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the present invention aims to provide a cold and heat source supply system based on the coupling of greywater reuse and water source heat pump. The purpose is to integrate wastewater waste heat recovery, greywater treatment and water source heat pump technology through structural system modification.

[0010] The following section details the system composition and implementation measures from three aspects: wastewater collection and filtration, extraction of cold and heat sources by water source heat pumps, and reuse of extracted wastewater.

[0011] A cold and heat source supply system based on greywater reuse and water source heat pump coupling includes a control center, a wastewater collection pipe installed in the apartment, a greywater filtration unit connected to the rear of the wastewater collection pipe, the greywater filtration unit connected to the water source heat pump unit, and the water source heat pump unit connected to the air conditioning terminal in the apartment. The rear side of the water source heat pump unit is connected to a wastewater deep treatment unit, which deeply treats the wastewater from the water source heat pump unit and then uses it for non-drinking domestic use. The apartment is equipped with an outdoor temperature and humidity transmitter. The wastewater collection pipe extends into the room and connects to the drain outlets of the bathroom, washing machine, and washbasin. A primary filtration module is installed at the connection between the wastewater collection pipe and the greywater filtration unit, which is used to filter out larger impurities in the wastewater. The apartment is also equipped with an air source heat pump unit that is connected to the air conditioning terminals inside the apartment to assist in regulating the indoor temperature.

[0012] The apartment is externally connected to a solar water heating system, which includes a double ventilation pipe, a connecting box, a wind-water heat exchanger, and a makeup air fan. The double ventilation pipe, the connecting box, and the wind-water heat exchanger are connected end to end to form a ring passage, and a circulating fan is installed on the ring passage. The water tank and the wind-water heat exchanger are connected by a circulating pump to achieve hot water circulation.

[0013] The aforementioned greywater filtration unit employs a multi-stage sedimentation and separation design, comprising a collection tank, a sedimentation zone, an oil-water separator, and a homogenization and equalization tank. The oil-water separator separates the sedimentation zone from the upper part of the homogenization and equalization tank. At the bottom of the oil-water separator, a connecting pipe connects the sedimentation zone to the homogenization and equalization tank. The greywater filtration unit removes suspended solids (SS) and some organic matter from the water, ensuring the water quality meets the basic requirements of the water source heat pump unit for suspended solids content in wastewater (typically requiring SS ≤ 30 mg / L).

[0014] The homogenization and equalization tank is equipped with a submersible mixer to prevent suspended solids from settling and to homogenize the water temperature and quality. A level sensor is also installed in the homogenization and equalization tank to control the start and stop of the subsequent booster pump.

[0015] The water source heat pump unit consists of wastewater-side circulation and user-side circulation, and is used to replace municipal heating and split air conditioners. The wastewater-side circulation involves wastewater in the equalization tank being pumped to the water source heat pump unit and entering the wastewater heat exchanger. To prevent clogging, a backwashing filter is installed before the wastewater heat exchanger. In the wastewater heat exchanger, the wastewater exchanges heat with the intermediate circulation medium. After the heat exchange, the temperature of the wastewater decreases (in winter) or increases (in summer), and then it is discharged to the subsequent reuse unit. The heat pump unit of the water source heat pump unit adopts a water ring / sewage source heat pump unit. The water source heat pump unit is equipped with a four-way reversing valve to realize the switching of operating conditions.

[0016] The wastewater deep treatment unit includes a primary sedimentation tank, an overflow tank, a coagulation sedimentation tank, and an oxidation tank. An overflow hole is provided on the partition between the primary sedimentation tank and the overflow tank. The rear side of the overflow tank is the coagulation sedimentation tank. A reagent tank is provided on the top of the coagulation sedimentation tank. Several baffles are provided in the reagent tank to achieve reagent mixing and finally flow into the coagulation sedimentation tank. The oxidation tank is located behind the coagulation sedimentation tank and has a grid plate inside. A biological bacteria fixed bed is suspended on the grid plate for oxidizing the water. The treated water enters the clear water storage tank.

[0017] The clear water storage tank is equipped with a chlorine dioxide generator or an ultraviolet disinfection device to sterilize it, with the aim of meeting the "Water Quality Standard for Urban Wastewater Reuse for Miscellaneous Uses" (GB / T 18920).

[0018] Terminal utilization pipeline: An independent greywater supply network is set up, with one line connected to the green belt sprinkler system; the other line is raised to the apartment building and connected to the original toilet flushing tank inlet pipe to replace tap water for flushing toilets.

[0019] The operation method of the cold and heat source supply system based on greywater reuse and water source heat pump coupling is as follows: Outdoor temperature sensing and seasonal operating condition identification: Outdoor temperature and humidity transmitters are installed outside the apartment building; the control center has a dual threshold comparison program. When the outdoor temperature is detected to be below 10℃ for 30 consecutive minutes, it is judged as winter operating condition, and the system starts the water source heat pump unit for heating circulation; when the outdoor temperature is above 22℃ for 30 consecutive minutes, it is judged as summer operating condition, the four-way reversing valve switches to the cooling position, the water source heat pump unit for cooling circulation starts, and the heating circulation pump is shut down; when the temperature is between 10℃ and 22℃, the cold and heat source equipment is shut down and in standby mode, and the greywater filtration unit continues to operate independently. Meteorological feedforward and load regulation: Radiation sensors and wind speed and direction sensors are installed on the roof; in cooling mode, when the rate of change of irradiance exceeds 200W / (m²·min) and the humidity is higher than 60%, the PLC outputs a feedforward compensation signal to the inverter of the water source heat pump unit, increasing the compressor operating frequency by 5%~20%; in heating mode, when the outdoor temperature drops by more than 2℃ / 15min or the wind speed remains higher than level 5, the system automatically adjusts the heating water supply temperature setpoint and increases the circulation pump frequency by 10%. Online monitoring and protection of wastewater quality: The system is equipped with several water quality monitoring points, including a turbidity meter and a pH electrode installed at the inlet of the collection tank; This includes installing a conductivity meter and an online COD analyzer at the outlet of the homogenization and conditioning tank; This includes installing temperature sensors and electromagnetic flow meters on the wastewater side of the water source heat pump unit; The control logic is as follows: When the turbidity at the detection point in the collection tank is ≥50 NTU, the PLC increases the cleaning frequency to continuous operation and starts the sludge pump for a 20-minute delay. When the conductivity or COD of the equalization tank exceeds the set threshold, the system executes bypass protection, closes the electric valve for wastewater to enter the heat exchanger of the water source heat pump unit, opens the emergency drain pipe, and simultaneously starts the external clean water storage tank as a temporary heat source for circulation. After the water quality detection is reset, it automatically switches back after a 5-minute delay. The thermal resistance of the heat exchanger is calculated based on the temperature difference and flow rate between the wastewater side of the water source heat pump unit and the equalization tank. When the thermal resistance growth rate exceeds the preset curve, the automatic backwashing program is triggered for backwashing, with a backwashing time of 3 minutes per cycle.

[0020] Secondary advanced wastewater treatment: A residual chlorine detector and an E. coli monitor are installed at the outlet of the clear water storage tank of the advanced wastewater treatment unit. If the residual chlorine is lower than 0.2 mg / L or the colony count exceeds the standard, the control center will prohibit the start of the reclaimed water supply pump, and will also sound an alarm and automatically open the solenoid valve on the tap water supply pipeline to switch to tap water for toilet flushing. After the disinfection system is adjusted and re-inspected and passes the test, the reclaimed water supply pump will automatically unlock and resume operation.

[0021] With the above-mentioned device and system, during winter operation, the "waste hot water" discharged from the apartment is treated by the greywater filtration unit and then pumped into the sewage heat exchanger of the water source heat pump unit. The evaporator of the water source heat pump unit absorbs heat, and the condenser produces 45°C hot water for heating. The cooled wastewater enters the wastewater deep treatment unit for secondary treatment, and after disinfection, it is used for toilet flushing or landscaping. During summer operation, the "domestic water" discharged from the apartment is treated by the greywater filtration unit and then pumped into the sewage heat exchanger of the water source heat pump unit. Heat exchange occurs in the condenser of the water source heat pump unit, and the water temperature on the evaporator side drops to 7°C for cooling. The heated wastewater enters the wastewater deep treatment unit for secondary treatment, and after disinfection, it is used for toilet flushing or landscaping, while simultaneously achieving physical cooling of the wastewater. When students are on vacation, the apartment basically does not discharge waste hot water, or when only a small amount is discharged, the wastewater is directly discharged into the sewer. The above operating procedures can make full use of the heat from the drainage of the apartment's centralized water supply, minimize the use of external heating or cooling energy, and enable the secondary use of water sources. It is an ideal cold and heat source supply system based on the coupling of greywater reuse and water source heat pump. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a schematic diagram of the connection structure in use for the invention; Figure 2 This is a schematic diagram illustrating the operating principle of the invention. In the diagram: 1. Solar water heating system, 11. Double ventilation pipe, 12. Connection box, 13. Air-water heat exchanger, 14. Make-up air fan, 15. Circulating fan, 16. Water pipe, 17. Water tank, 18. Water supply pump; 2. Apartment; 21. Washbasin; 22. Air conditioning terminal; 23. Washing machine; 24. Shower room; 25. Primary filter module; 26. Radiation sensor; 27. Wind speed and direction sensor; 28. Outdoor temperature and humidity transmitter. 3. Air source heat pump unit; 31. Control switch; 4. Greywater filtration unit; 41. Water collection tank; 42. Sedimentation zone; 43. Oil separation zone; 44. Homogenization and equalization tank; 45. Circulating pipe; 46. Wastewater supply pump; 47. Turbidity meter; 48. pH electrode; 49. Conductivity meter; 40. COD online analyzer; 441. Emergency drainage pipe; 442. External clean water storage pipe. 5. Water source heat pump unit; 51. Water source heat pump switch; 52. Temperature sensor; 53. Electromagnetic flow meter; 6. Wastewater deep treatment unit; 60. Primary sedimentation tank; 61. Overflow tank; 62. Coagulation sedimentation tank; 63. Oxidation tank; 631. Bar screen; 64. Clear water storage tank; 65. Liquid pump; 66. Outlet pipe; 67. Residual chlorine detector; 68. E. coli monitor; 69. Reclaimed water supply pipe; 70. Reclaimed water supply pump. 7. Control Center. Detailed Implementation

[0023] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0024] Example 1: As Figure 1 As shown, this embodiment provides a cold and heat source supply system based on greywater reuse and water source heat pump coupling, including a control center 7, a wastewater collection pipe installed in apartment 2, a greywater filtration unit 4, a water source heat pump unit 5, and a wastewater deep treatment unit 6.

[0025] The wastewater collection pipe extends into apartment 2 and connects to the drain outlets of the bathroom 24, washing machine 23, and washbasin 21, respectively, to collect the bathing and washing wastewater discharged from the student apartment. A primary filtration module 25 is installed at the connection between the wastewater collection pipe and the greywater filtration unit 4 to initially intercept and filter larger impurities (such as hair, fabric fibers, solid particles, etc.) in the wastewater. The primary filtration module 25 can adopt a commercially available filter structure.

[0026] The greywater filtration unit 4 adopts a multi-stage sedimentation and separation design, and is arranged sequentially from the inlet side as a water collection tank 41, a sedimentation zone 42, an oil-water separation zone 43, and a homogenization and equalization tank 44. A turbidity meter 47 (range 0~100 NTU) and a pH electrode 48 (range 0~14) are installed at the inlet of the water collection tank 41. The oil-water separation zone 43 separates the sedimentation zone 42 from the upper part of the homogenization and equalization tank 44, and a conductive pipe 45 is installed at the bottom of the oil-water separation zone 43 to connect the sedimentation zone 42 and the homogenization and equalization tank 44. A conductivity meter 49 (range 0~20000 μS / cm) and a COD online analyzer 40 are installed at the outlet of the homogenization and equalization tank 44. The COD online analyzer uses ultraviolet absorption and has a range of 0~500 mg / L. The homogenization tank 44 is equipped with a submersible mixer to prevent suspended solids from settling and to homogenize the water temperature and quality. It is also equipped with a liquid level sensor to control the start and stop of the subsequent wastewater supply pump 46. When the liquid level is low, the wastewater supply pump 46 is turned off.

[0027] The rear side of the greywater filtration unit 4 is connected to the water source heat pump unit 5 via a wastewater supply pump 46 and pipelines. The water source heat pump unit 5 consists of wastewater-side circulation and user-side circulation. A temperature sensor 52 and an electromagnetic flow meter 53 (accuracy ±0.5%) are installed on the wastewater side of the water source heat pump unit 5. A heat exchanger is installed on the wastewater-side circulation pipeline as a sewage heat exchanger. A backwashing filter is installed before the sewage heat exchanger. This backwashing filter can use a pulse spray valve to clean the sewage heat exchanger with pulse water supply when needed to prevent clogging. The heat pump unit of the water source heat pump unit 5 is a water ring / sewage source heat pump unit with an internal four-way reversing valve to switch between cooling and heating modes. The water source heat pump unit 5 controls whether to provide heating or cooling to apartment 2 via a water source heat pump switch 51.

[0028] The user side of the water source heat pump unit 5 is connected to the air conditioning terminal 22 (such as a fan coil unit) in apartment 2. An outdoor temperature and humidity transmitter (measuring range -20~60℃, accuracy ±0.5℃) is installed outside apartment 2 to collect outdoor temperature and humidity data in real time and transmit it to the control center 7.

[0029] The water source heat pump unit 5 is connected to the wastewater advanced treatment unit 6 via a pump 65. The wastewater advanced treatment unit 6 includes a primary sedimentation tank 60, an overflow tank 61, a coagulation sedimentation tank 62, and an oxidation tank 63. An overflow hole is provided on the partition between the primary sedimentation tank 60 and the overflow tank 61. The coagulation sedimentation tank 62 is located behind the overflow tank 61, and a chemical tank is installed at the top of the coagulation sedimentation tank 62. Several baffles are installed inside the chemical tank to mix the chemicals and allow them to flow into the coagulation sedimentation tank 62. The oxidation tank 63 is located behind the coagulation sedimentation tank 62 and contains a grid plate 631 with a suspended biological bacteria bed for oxidizing the water. The treated water enters a clear water storage tank 64. The clear water storage tank 64 is equipped with a chlorine dioxide generator or an ultraviolet disinfection device for end-point sterilization. A residual chlorine detector 67 (range 0~5mg / L) and an E. coli monitor 68 (enzyme substrate method, detection cycle 2h) are installed at the outlet of the clear water storage tank 64.

[0030] After the wastewater is treated by the advanced wastewater treatment unit 6, it is used for non-drinking domestic purposes: the clear water storage tank 64 is connected to the inlet pipe of the toilet flushing tank in the second floor of the apartment through the greywater supply pump 70 and the greywater supply pipe 69, replacing the tap water for flushing toilets; at the same time, another line is connected to the green belt sprinkler system through the external discharge pipe 66.

[0031] An air source heat pump unit 3 is also installed outside the apartment 2, which is connected to the air conditioning terminal 22 inside the apartment 2 through a control switch 31 to achieve auxiliary regulation of indoor temperature.

[0032] The apartment 2 is also connected to a solar water heating system 1, which includes a double ventilation pipe 11, a connecting box 12, a wind-water heat exchanger 13, and a makeup air fan 14. The double ventilation pipe 11, the connecting box 12, and the wind-water heat exchanger 13 are connected end to end to form a ring passage, and a circulating fan 15 is installed on the ring passage. The water tank 17 is connected to the wind-water heat exchanger 13 through a water pipe 16 and a circulating pump to realize hot water circulation. The water tank 17 supplies hot water to the apartment 2 through a water supply pump 18.

[0033] The roof of apartment 2 is equipped with a radiation sensor 26 (measuring range 0~2000W / m²) and a wind speed and direction sensor 27 for collecting meteorological parameters and transmitting them to the control center 7.

[0034] An outdoor temperature and humidity transmitter 28 (measuring range -20~60℃, accuracy ±0.5℃) is installed on the shaded side of apartment 2 to collect outdoor temperature parameters and transmit them to the control center 7.

[0035] Example 2: System Usage Method This embodiment provides an operation method for a cold and heat source supply system based on greywater reuse and water source heat pump coupling, including the following steps: (I) Outdoor Temperature Sensing and Seasonal Operating Condition Identification: A dual threshold comparison program is set up in the control center 7 (PLC). When the outdoor temperature is detected to be below 10℃ for 30 consecutive minutes, it is judged as winter operating condition. The system starts the heating cycle of the water source heat pump unit 5, cuts off the power supply circuit of the split air conditioner, and closes the electric valve of the municipal heating inlet. The actions of cutting off the power supply circuit of the split air conditioner and closing the electric valve of the municipal heating inlet can be manually controlled or remotely automatically controlled. When the outdoor temperature is above 22℃ for 30 consecutive minutes, it is judged as summer operating condition. The four-way reversing valve inside the water source heat pump unit 5 switches to the cooling position, starts the cooling cycle of the water source heat pump unit 5, and shuts down the heating cycle pump. When the temperature is between 10℃ and 22℃, the cold and heat source equipment stops and stands by, and the greywater filtration unit 4 continues to operate independently.

[0036] (ii) Wastewater collection and primary filtration: Domestic wastewater discharged from bathroom 24, washing machine 23 and washbasin 21 in apartment 2 flows into wastewater collection pipe through drain outlet. After being intercepted by primary filtration module 25, larger impurities are intercepted and then enter the collection tank 41 of greywater filtration unit 4.

[0037] (III) Greywater Filtration Treatment: After being collected in the collection tank 41, the wastewater flows sequentially through the sedimentation zone 42 for natural settling. It then passes through the oil separator 43 to remove floating oil and light impurities. The bottom wastewater enters the equalization tank 44 through the guide pipe 45 for water quality and quantity balancing. A submersible mixer in the equalization tank 44 is periodically activated to prevent suspended solids from settling and to even out water temperature and quality. After treatment by the greywater filtration unit 4, the suspended solids (SS) content in the wastewater is reduced to ≤30mg / L, meeting the basic requirements for influent water quality for the water source heat pump unit 5.

[0038] (iv) Online monitoring and protection of wastewater quality: The system is equipped with a turbidity meter 47 and a pH electrode 48 at the inlet of the collection tank 41, a conductivity meter 49 and an online COD analyzer 40 at the outlet of the equalization tank 44, and a temperature sensor 52 and an electromagnetic flow meter 53 on the wastewater side of the water source heat pump unit 5. The control logic is as follows: When the turbidity in the collection tank 41 is ≥50 NTU, the control center 7 increases the cleaning frequency to continuous operation and starts the sludge pump for a 20-minute delay. When the conductivity or COD of the equalization tank 44 exceeds the set threshold (conductivity ≥5000 μS / cm or COD ≥300 mg / L), the system performs bypass protection, closes the electric valve for wastewater to enter the heat exchanger of the water source heat pump unit 5, opens the emergency drain pipe 441, and simultaneously activates the external clean water storage pipe 442 (connected to the external clean water storage tank) as a temporary heat source for circulation. After the water quality test is reset, it automatically switches back after a 5-minute delay. The heat exchanger thermal resistance is calculated based on the temperature difference and flow rate between the wastewater side of the water source heat pump unit 5 and the equalization tank 44. When the thermal resistance growth rate exceeds the preset curve, the automatic backwashing program is triggered for backwashing, with a backwashing time of 3 minutes per cycle.

[0039] (v) Operation of water source heat pump unit: Wastewater that meets the water quality standards is transported by wastewater supply pump 46 to the sewage heat exchanger of water source heat pump unit 5.

[0040] Winter operation: The evaporator of the water source heat pump unit 5 absorbs heat from the wastewater, and the condenser produces 45°C hot water, which is circulated to the air conditioning terminal 22 (radiator or floor radiant heating terminal) in apartment 2 through the user side to provide heating. After heat exchange, the wastewater temperature decreases and is discharged into the subsequent wastewater deep treatment unit 6.

[0041] Summer operation: The four-way reversing valve inside the water source heat pump unit 5 switches to the cooling position, and the wastewater enters the condenser of the water source heat pump unit 5 for heat exchange. The water temperature on the evaporator side drops to 7°C, and the chilled water is then circulated to the air conditioning terminal 22 (fan coil unit) in apartment 2 to provide cooling. After heat exchange, the wastewater temperature rises and is discharged into the subsequent wastewater deep treatment unit 6, which also achieves physical cooling of the wastewater.

[0042] (vi) Meteorological Feedforward and Load Regulation: The radiation sensor 26 (measurement range 0~2000W / m²) and wind speed and direction sensor 27 installed on the roof collect meteorological parameters in real time. In cooling mode, when the irradiance change rate exceeds 200W / (m²·min) and the humidity is higher than 60%, the PLC of the control center outputs a feedforward compensation signal to the inverter of the water source heat pump unit 5 to increase the compressor operating frequency by 5%~20% (adjustable in 10% steps). In heating mode, when the outdoor temperature drops by more than 2℃ / 15min or the wind speed is continuously higher than level 5 (8.0m / s), the system automatically increases the heating water supply temperature setpoint (increase by 3℃) and increases the circulation pump frequency by 10%; when the outdoor temperature is below -10℃ or above 38℃, the system automatically switches to full load operation and turns on the electric auxiliary heating device (heating mode) or small closed cooling tower (cooling mode) as an auxiliary.

[0043] (VII) Advanced Wastewater Treatment and Reuse: Wastewater after heat exchange by the water source heat pump unit 5 enters the advanced wastewater treatment unit 6. First, it enters the primary sedimentation tank 60 for natural settling. The supernatant flows through the overflow hole into the overflow tank 61, and then into the coagulation sedimentation tank 62. A coagulant (such as polyaluminum chloride) is added to the reagent tank at the top of the coagulation sedimentation tank 62. After mixing by baffles, it flows into the coagulation sedimentation tank 62 for coagulation and sedimentation reaction. The supernatant after sedimentation enters the oxidation tank 63, where a biological bacteria fixed bed suspended from the grid plate 631 performs biological oxidation treatment on the water. The treated water enters the clear water storage tank 64, where it is sterilized by a chlorine dioxide generator or ultraviolet disinfection device, and the water quality meets the standard of "Urban Wastewater Reuse for Urban Miscellaneous Water" (GB / T 18920).

[0044] The residual chlorine detector 67 and the E. coli monitor 68 installed at the outlet of the clear water storage tank 64 monitor the effluent water quality in real time. If the residual chlorine is below 0.2 mg / L or the bacterial count exceeds the standard, the control center 7 will prevent the reclaimed water supply pump 70 from starting, and will also sound an alarm and automatically open the solenoid valve on the tap water supply pipeline to switch to tap water for toilet flushing; after the disinfection system is adjusted and re-inspected and passes the test, the reclaimed water supply pump 70 will automatically unlock and resume operation.

[0045] After meeting the standards, the reclaimed water is transported to the second floor of the apartment through the reclaimed water supply pump 70 and the reclaimed water supply pipe 69, and connected to the original toilet flushing tank inlet pipe to replace the tap water for flushing toilets; at the same time, it is transported to the green belt through the external drainage pipe 66 for greening and watering.

[0046] (viii) Operation of auxiliary energy system: When the dormitory basically does not discharge waste hot water or the discharge volume is insufficient during student holidays, the wastewater is directly discharged into the sewer after primary filtration. At this time, the air source heat pump unit 3 can be used as an auxiliary cold and heat source according to the outdoor temperature conditions. It is started by the control switch 31 and connected to the air conditioning terminal 22 to realize the auxiliary regulation of indoor temperature. The solar water heating system 1 collects solar heat through a ring passage consisting of double ventilation pipes 11, connection box 12, air-water heat exchanger 13 and circulating fan 15. After heat exchange through water pipe 16, it is stored in water tank 17 and supplied to dormitory 2 by water supply pump 18.

[0047] (ix) System shutdown: During non-cooling and heating seasons (when the average daily outdoor temperature is between 10℃ and 22℃), the cold and heat source equipment (water source heat pump unit 5 and air source heat pump unit 3) are shut down and put on standby. The greywater filtration unit 4 and the wastewater deep treatment unit 6 operate independently, continuously treating wastewater and supplying greywater for toilet flushing and greening.

Claims

1. A cold and heat source supply system based on greywater reuse coupled with a water source heat pump, characterized in that, include: Wastewater collection pipes are installed in the apartment (2) and connected to the drain outlets of the bathroom (24), washing machine (23), and washbasin (21), respectively; The greywater filtration unit (4) is connected to the rear side of the wastewater collection pipe; The water source heat pump unit (5) is connected to the rear side of the greywater filtration unit (4), and its user side is connected to the air conditioning terminal (22) in the apartment (2). Wastewater deep treatment unit (6) is connected to the rear side of the water source heat pump unit (5); The control center (7) is connected to the greywater filtration unit (4), the water source heat pump unit (5), the wastewater deep treatment unit (6), the outdoor temperature and humidity transmitter (28), and other signal systems. The outdoor temperature and humidity transmitter (28) is installed outside the apartment (2).

2. The cold and heat source supply system based on greywater reuse and water source heat pump coupling according to claim 1, characterized in that, The greywater filtration unit (4) includes a water collection tank (41), a sedimentation zone (42), an oil separation zone (43), and a homogenization and conditioning tank (44). The oil separation zone (43) separates the sedimentation zone (42) from the upper part of the homogenization and conditioning tank (44), and a guide pipe (45) is provided at the bottom. The inlet of the water collection tank (41) is equipped with a turbidity meter (47) and a pH electrode (48), and the outlet of the homogenization and conditioning tank (44) is equipped with a conductivity meter (49) and an online COD analyzer (40). It is also equipped with a submersible mixer and a liquid level sensor inside.

3. The cold and heat source supply system based on greywater reuse and water source heat pump coupling according to claim 1, characterized in that, The water source heat pump unit (5) includes wastewater side circulation and user side circulation. The wastewater side is equipped with a sewage heat exchanger and a backwash filter at the front end. It is equipped with a four-way reversing valve inside, and a temperature sensor (52) and an electromagnetic flow meter (53) are installed on the wastewater side.

4. The cold and heat source supply system based on greywater reuse and water source heat pump coupling according to claim 1, characterized in that, The wastewater deep treatment unit (6) includes a primary sedimentation tank (60), an overflow tank (61), a coagulation sedimentation tank (62), an oxidation tank (63), and a clear water storage tank (64) connected in sequence. An overflow hole is provided between the primary sedimentation tank (60) and the overflow tank (61). A chemical tank with a baffle is provided on the top of the coagulation sedimentation tank (62). A grid plate (631) and a suspended biological bacteria fixed bed are provided in the oxidation tank (63). The clear water storage tank (64) is equipped with a disinfection device and is connected to the toilet flushing tank and the greening sprinkler system through a greywater supply pump (70) and pipelines. A residual chlorine detector (67) and an E. coli monitor (68) are provided at its outlet.

5. The cold and heat source supply system based on greywater reuse and water source heat pump coupling according to claim 1, characterized in that, It also includes an air source heat pump unit (3) and a solar water heating system (1). The air source heat pump unit (3) is connected to the air conditioning terminal (22). The solar water heating system (1) includes a ring passage consisting of a double ventilation pipe (11), a connecting box (12), a wind-water heat exchanger (13), and a circulating fan (15). The wind-water heat exchanger (13) is connected to a water tank (17) through a water pipe (16). The water tank (17) supplies hot water through a water supply pump (18). The apartment (2) roof is also equipped with a radiation sensor (26) and a wind speed and direction sensor (27).

6. An operation method for a cold and heat source supply system based on greywater reuse and water source heat pump coupling as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Outdoor temperature sensing and seasonal operating condition identification: Based on the temperature collected by the outdoor temperature and humidity transmitter, when the outdoor temperature is detected to be below 10℃ for 30 consecutive minutes, the heating cycle is started; when it is above 22℃, the cooling cycle is switched; and when it is between the two, the machine is stopped and put into standby mode. Step 2, Wastewater collection and primary filtration: Collect domestic wastewater and pass it through the primary filtration module (25) to intercept large impurities before entering the greywater filtration unit (4); Step 3, greywater filtration treatment: The wastewater is treated sequentially through the collection tank (41), sedimentation zone (42), oil separation zone (43), and equalization tank (44), and the effluent meets the water inlet requirements of the water source heat pump unit (5); Step 4: Operation of the water source heat pump unit: Qualified wastewater enters the sewage heat exchanger for heat exchange, extracting heat for heating in winter and using wastewater for cooling in summer; Step 5: Advanced wastewater treatment and reuse: The wastewater after heat exchange is treated by sedimentation, coagulation, biological oxidation and disinfection, and after meeting the standards, it is used for toilet flushing and greening irrigation.

7. The operation method of the cold and heat source supply system based on greywater reuse and water source heat pump coupling according to claim 6, characterized in that, In step three, when the turbidity of the collection tank (41) is ≥50 NTU, the cleaning frequency is increased and the sludge pump is started; when the conductivity of the equalization tank (44) is ≥5000 μS / cm or COD is ≥300 mg / L, bypass protection is implemented, the electric valve for wastewater entering the heat exchanger is closed and the emergency drainage and external clean water storage tank / pipe are opened, and the system is switched back after a delay after the water quality is reset.

8. The operation method of the cold and heat source supply system based on greywater reuse and water source heat pump coupling according to claim 6, characterized in that, In step four, the heat exchanger thermal resistance is calculated based on the wastewater side temperature sensor (52) and electromagnetic flow meter (53). When the thermal resistance growth rate exceeds the preset curve, the automatic backwashing program is triggered, and the backwashing time is 3 minutes / time.

9. The operation method of the cold and heat source supply system based on greywater reuse and water source heat pump coupling according to claim 6, characterized in that, It also includes meteorological feedforward load adjustment: based on the data of radiation sensor (26) and wind speed and direction sensor (27), when the irradiance change rate exceeds 200W / (m²·min) and the humidity is >60% in the cooling mode, the compressor frequency is increased by 5%~20%; in the heating mode, when the temperature drop rate exceeds 2℃ / 15min or the wind speed is continuously higher than level 5, the heating water supply temperature is increased by 3℃ and the circulation pump frequency is increased by 10%.

10. The operation method of the cold and heat source supply system based on greywater reuse and water source heat pump coupling according to claim 6, characterized in that, In step five, the residual chlorine and E. coli at the outlet of the clear water storage tank (64) are monitored in real time. When the residual chlorine is lower than 0.2 mg / L or the bacterial count exceeds the standard, the water supply pump (70) is prohibited from starting and an alarm is triggered. The system is automatically switched to tap water for toilet flushing and will be restored after a re-inspection.

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