Multi-energy complementary vacuum membrane distillation wastewater treatment system

Abstract

The utility model discloses a multi-energy complementary vacuum membrane distillation wastewater treatment system, and belongs to the field of wastewater treatment. The system mainly comprises a mid-deep rock hot well group (1), first to sixth control valves, a steam compression heat pump (4), first to third water tanks, a first circulating pump (10-1), a second circulating pump (10-2), a solar heat collector (12), a first heat exchanger (13-1), a second heat exchanger (13-2), a vacuum membrane assembly (14) and a vacuum pump (15). Wherein the steam compression type heat pump (4) consists of a compressor (5), an evaporator (6), a condenser (7) and a throttle valve (8). The system can recycle geothermal energy, solar energy and secondary steam heat energy to the maximum extent, meets the energy requirement in the vacuum membrane distillation wastewater treatment process through multi-energy complementation, has the advantages of high energy utilization efficiency, low operation cost, high operation stability and the like, and is suitable for the fields of industrial heat supply, building heating, ventilation and air conditioning and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of multi-energy complementary vacuum membrane distillation wastewater treatment system, belong to energy conservation and environmental protection field. BACKGROUND

[0002] Vacuum membrane distillation is a new separation technology in recent years, which can be widely applied in industrial wastewater treatment, seawater desalination, traditional Chinese medicine concentration and food industry. Vacuum membrane distillation system is mainly composed of vacuum membrane assembly, circulating pump, raw material tank, condensate tank and vacuum pump and other components. The vacuum membrane assembly is composed of multiple hollow fiber membrane tubes, each of which is made of polytetrafluoroethylene hydrophobic microporous membrane. Under the drive of circulating pump, the raw liquid in raw material tank fills the hot side of vacuum membrane assembly, and a certain negative pressure environment is created on the cold side of vacuum membrane assembly by vacuum pump. Under the driving of vapor pressure difference on both sides of hydrophobic membrane, water molecules in the solution on the surface of hot side membrane evaporate and pass through the membrane hole to the cold side, and finally condense in the condenser, so as to separate the raw liquid into concentrated liquid and fresh water. However, due to membrane pollution, temperature and concentration polarization and lack of latent heat recovery device, the existing vacuum membrane distillation system generally has poor thermodynamic performance and low energy utilization efficiency, which limits the industrial application of vacuum membrane distillation technology.

[0003] Renewable energy is a resource that can be continuously regenerated and sustainably used in nature, mainly including solar energy, geothermal energy, wind energy, water energy, biomass energy and ocean energy, etc. which is very rich and can be widely obtained. Among them, solar energy is the most common renewable energy, which has the advantages of clean, continuous and huge energy, etc. It mainly collects and utilizes solar radiation energy through the ways of photo-thermal conversion and photo-electric conversion to meet the needs of heating, power generation and other needs, and has a very broad application prospect. Geothermal energy is a natural heat energy extracted from molten lava inside the earth, which is also a clean renewable energy. It has the advantages of large reserves, wide distribution, green and low carbon, strong applicability and good stability. Especially the middle-deep layer geothermal energy, by installing airtight metal heat exchanger in the underground drill hole, using the circulation of the medium in the heat exchanger, the heat energy in the deep underground is extracted and discharged, and high-efficiency heat pump units and other equipment are used to meet the energy needs of human beings such as heating, hot water, refrigeration and other needs. In addition, this technology has no interference to the natural environment and no influence to the geological environment such as underground water layer and soil, which has the advantages of environmental protection and sustainability.

[0004] At present, although solar energy and middle-deep layer geothermal energy technology has gradually been applied in China, it is widely used in the field of heating, ventilation and air conditioning, but there is little research on its application in the field of industrial wastewater treatment, especially in the field of vacuum membrane distillation process. Therefore, coupling solar energy and middle-deep layer geothermal energy technology to efficiently and low-costly meet the energy demand of vacuum membrane distillation system in the process of treating industrial wastewater has important value and significance for the industrial application of vacuum membrane distillation technology. The utility model discloses a kind of low energy consumption, strong stability's multi-energy complementary vacuum membrane distillation wastewater treatment system.

[0005] The utility model discloses a kind of low energy consumption, strong stability's multi-energy complementary vacuum membrane distillation wastewater treatment system.

[0006] A kind of multi-energy complementary vacuum membrane distillation wastewater treatment system, it is characterized in that mainly includes: middle-deep layer ground rock heat well group, first control valve, second control valve, third control valve, fourth control valve, fifth control valve, sixth control valve, steam compression heat pump, first water tank, second water tank, third water tank, first circulating pump, second circulating pump, solar energy collector, first heat exchanger, second heat exchanger, vacuum membrane assembly, vacuum pump.Steam compression heat pump is composed of compressor, evaporator, condenser and throttle valve;Wherein middle-deep layer ground rock heat well group outlet is connected with the cold side import of second heat exchanger through first control valve, the cold side outlet of second heat exchanger is connected with the hot side import of evaporator in steam compression heat pump, and evaporator hot side outlet is connected with middle-deep layer ground rock heat well group import through second control valve;Wherein evaporator cold side outlet is connected with the import of compressor, and the hot side import of condenser is connected with the outlet of compressor, and the hot side outlet of condenser is connected with the cold side import of evaporator through throttle valve;Wherein first water tank outlet is connected with the import of first circulating pump through fourth control valve, and the cold side import of condenser is connected with the outlet of first circulating pump, and the cold side outlet of condenser is connected with solar energy collector import through third control valve, and the hot side import of first heat exchanger is connected with solar energy collector outlet, and the import of first water tank is connected with first heat exchanger hot side outlet;Wherein second water tank outlet is connected with the import of second circulating pump through fifth control valve, and the cold side import of first heat exchanger is connected with the outlet of second circulating pump, and the import of vacuum membrane assembly pipe is connected with first heat exchanger cold side outlet, and the import of second water tank is connected with vacuum membrane assembly pipe outlet;The hot side import of second heat exchanger is connected with the outlet of vacuum membrane assembly shell, and the import of third water tank is connected with second heat exchanger hot side outlet through sixth control valve, and vacuum pump is connected with the outlet of third water tank.

[0007] The working method of the solar-powered deep geothermal multi-energy complementary vacuum membrane distillation wastewater treatment system is as follows: the first control valve and the second control valve are opened, and the liquid working fluid water absorbs geothermal energy and is heated by the deep geothermal well group. Then it enters the cold side of the second heat exchanger to absorb the waste heat of the steam and is further heated. After being heated twice, the liquid working fluid water enters the hot side of the evaporator in the vapor compression heat pump unit, releasing heat to the refrigerant circulating working fluid on the cold side of the evaporator, and then returns to the mid-deep geothermal well group to absorb geothermal energy. The refrigerant working fluid absorbs heat and evaporates into steam on the cold side of the evaporator, enters the compressor for compression into high-temperature and high-pressure steam, and then enters the hot side of the condenser to release heat through condensation into low-temperature and high-pressure liquid working fluid. The low-temperature and high-pressure liquid working fluid then passes through a throttling valve to reduce its pressure into low-temperature and low-pressure liquid working fluid, and finally enters the cold side of the evaporator to continue absorbing heat and evaporating. When the third control valve, the fourth control valve, and the first circulation pump are opened, the liquid working fluid water in the first water tank enters the cold side of the condenser to absorb heat from the refrigerant working fluid under the drive of the first circulation pump, and then enters the solar collector to absorb solar energy. The solution is further heated before entering the hot side of the first heat exchanger to release heat, and finally returns to the cold side of the condenser to continue absorbing heat from the refrigerant. The fifth and sixth control valves are opened, and the solution to be treated in the second water tank is sent to the cold side of the first heat exchanger to absorb heat through the second circulation pump. Then, the tube side of the vacuum membrane distillation assembly is filled, and the vacuum pump is started to create a vacuum, so that the shell side of the vacuum membrane distillation assembly is under a certain negative pressure. The solution in the tube side of the vacuum membrane distillation assembly evaporates on the membrane surface and reaches the shell side under the drive of the vapor pressure difference on both sides of the membrane. The high-temperature vapor enters the hot side of the second heat exchanger through the shell side outlet of the vacuum membrane distillation assembly, condenses and releases heat, and is finally collected in the third water tank. Meanwhile, the concentrated solution in the tube side of the vacuum membrane distillation assembly enters the second water tank for further circulation and concentration until the required concentration is reached and then recycled.

[0008] The aforementioned multi-energy complementary vacuum membrane distillation wastewater treatment system is characterized by the complementary use of solar and geothermal energy as heat sources in the vacuum membrane distillation wastewater treatment process, eliminating the need for external heat sources and cooling water systems. This not only effectively utilizes renewable energy but also efficiently recycles and treats industrial wastewater.

[0009] The above-mentioned multi-energy complementary vacuum membrane distillation wastewater treatment system is characterized in that: the medium-deep geothermal well group is composed of multiple medium-deep geothermal wells connected in parallel, each medium-deep geothermal well has a diameter of 100-500 mm and a depth of 1000-4000 m, and uses coaxial sleeves and U-shaped tubes to realize the heat exchange between liquid water and geothermal energy.

[0010] The above-mentioned multi-energy complementary vacuum membrane distillation wastewater treatment system is characterized in that: the above-mentioned vapor compression heat pump is composed of a compressor, an evaporator, a condenser and a throttling valve, and the working fluid used is R134a, or R22, or R123.

[0011] The above-mentioned multi-energy complementary vacuum membrane distillation wastewater treatment system is characterized in that: the vacuum membrane module is composed of multiple hollow fiber membrane tubes, each membrane tube is made of polytetrafluoroethylene hydrophobic microporous membrane with a pore size of 0.1-0.5 μm.

[0012] The above-mentioned multi-energy complementary vacuum membrane distillation wastewater treatment system is characterized in that: the first water tank is used to store softened water, the second water tank is used to store industrial wastewater, and the third water tank is used to store condensed fresh water. Attached Figure Description

[0013] Figure 1 This utility model proposes a multi-energy complementary vacuum membrane distillation wastewater treatment system;

[0014] The labels in the diagram are as follows: 1. Medium-deep geothermal well group; 2. Medium-deep geothermal well; 3-1 First control valve; 3-2 Second control valve; 3-3 Third control valve; 3-4 Fourth control valve; 3-5 Fifth control valve; 3-6 Sixth control valve; 4. Vapor compression heat pump; 5. Compressor; 6. Evaporator; 7. Condenser; 8. Throttling valve; 9-1 First water tank; 9-2 Second water tank; 9-3 Third water tank; 10-1 First circulating pump; 10-2 Second circulating pump; 11. Solar energy; 12. Solar collector; 13-1 First heat exchanger; 13-2 Second heat exchanger; 14. Vacuum membrane module; 15. Vacuum pump. Detailed Implementation

[0015] Figure 1 This invention relates to a multi-energy complementary vacuum membrane distillation wastewater treatment system. See below for reference. Figure 1 Describe the specific working process of this technology.

[0016] The device operates as follows: First control valve 3-1 and second control valve 3-2 are opened. Liquid working fluid water absorbs geothermal energy and increases in temperature through the mid-deep geothermal well group 1. It then enters the cold side of the second heat exchanger 13-2 to absorb waste heat from the steam and further increase in temperature. After two heating cycles, the liquid working fluid water enters the hot side of the evaporator 6 in the vapor compression heat pump unit 4, releasing heat to the refrigerant circulating working fluid on the cold side of the evaporator 6. It then returns to the mid-deep geothermal well group 1 to absorb geothermal energy. The refrigerant working fluid absorbs heat and evaporates into steam on the cold side of the evaporator 6. It then enters the compressor 5 for compression into high-temperature, high-pressure steam. This steam then enters the hot side of the condenser 7, where it condenses and releases heat to become low-temperature, high-pressure liquid working fluid. This low-temperature, high-pressure liquid working fluid then passes through the throttling valve 8 to decrease in pressure, becoming low-temperature, low-pressure liquid working fluid. Finally, this low-temperature, low-pressure liquid working fluid enters the cold side of the evaporator 6 to continue absorbing heat and evaporating. The third control valve 3-3, the fourth control valve 3-4, and the first circulation pump 10-1 are opened. The liquid working fluid water in the first water tank 9-1 enters the cold side of the condenser 7 to absorb the heat of the refrigerant working fluid under the drive of the first circulation pump 10-1. Then it enters the solar collector 12 to absorb solar energy for further heating. Then it enters the hot side of the first heat exchanger 13-1 to release heat. Finally, it returns to the cold side of the condenser 7 to continue absorbing the heat of the refrigerant working fluid. The fifth control valve 3-5 and the sixth control valve 3-6 are opened, and the liquid to be treated in the second water tank 9-2 is sent to the cold side of the first heat exchanger 13-1 to absorb heat via the second circulation pump 10-2. Then, the tube side of the vacuum membrane distillation assembly 14 is filled, and the vacuum pump 15 is started to create a vacuum, so that the shell side of the vacuum membrane distillation assembly 14 is under a certain negative pressure. The tube side solution of the vacuum membrane distillation assembly 14 evaporates on the membrane surface and reaches the shell side under the drive of the vapor pressure difference across the membrane. The high-temperature vapor enters the hot side of the second heat exchanger 13-2 through the shell side outlet of the vacuum membrane distillation assembly 14, condenses and releases heat, and is finally collected in the third water tank 9-3. Meanwhile, the concentrated solution in the tube side of the vacuum membrane distillation assembly 14 enters the second water tank 9-2 for further circulation and concentration until the required concentration is reached and then recycled.

[0017] Although the specific implementation process of this utility model has been described in detail above with reference to the accompanying drawings, this does not limit this utility model. Those skilled in the art should understand that all changes and improvements made within the spirit and principles of this utility model and under its guidance are within the protection scope of this utility model.

Claims

1. A multi-energy complementary vacuum membrane distillation wastewater treatment system, characterized in that... Mainly includes: Medium-deep geothermal well group (1), first control valve (3-1), second control valve (3-2), third control valve (3-3), fourth control valve (3-4), fifth control valve (3-5), sixth control valve (3-6), vapor compression heat pump (4), first water tank (9-1), second water tank (9-2), third water tank (9-3). The system consists of a first circulating pump (10-1), a second circulating pump (10-2), a solar collector (12), a first heat exchanger (13-1), a second heat exchanger (13-2), a vacuum membrane assembly (14), and a vacuum pump (15); wherein the vapor compression heat pump (4) is composed of a compressor (5), an evaporator (6), a condenser (7), and a throttle valve (8); The outlet of the medium-deep geothermal well group (1) is connected to the cold side inlet of the second heat exchanger (13-2) via the first control valve (3-1), the cold side outlet of the second heat exchanger (13-2) is connected to the hot side inlet of the evaporator (6) in the vapor compression heat pump (4), and the hot side outlet of the evaporator (6) is connected to the inlet of the medium-deep geothermal well group (1) via the second control valve (3-2). The cold side outlet of the evaporator (6) is connected to the inlet of the compressor (5), the outlet of the compressor (5) is connected to the hot side inlet of the condenser (7), and the hot side outlet of the condenser (7) is connected to the cold side inlet of the evaporator (6) through the throttle valve (8). The outlet of the first water tank (9-1) is connected to the inlet of the first circulating pump (10-1) via the fourth control valve (3-4). The outlet of the first circulating pump (10-1) is connected to the cold side inlet of the condenser (7). The cold side outlet of the condenser (7) is connected to the inlet of the solar collector (12) via the third control valve (3-3). The outlet of the solar collector (12) is connected to the hot side inlet of the first heat exchanger (13-1). The hot side outlet of the first heat exchanger (13-1) is connected to the inlet of the first water tank (9-1). The outlet of the second water tank (9-2) is connected to the inlet of the second circulating pump (10-2) via the fifth control valve (3-5). The outlet of the second circulating pump (10-2) is connected to the cold side inlet of the first heat exchanger (13-1). The cold side outlet of the first heat exchanger (13-1) is connected to the tube side inlet of the vacuum membrane module (14). The tube side outlet of the vacuum membrane module (14) is connected to the inlet of the second water tank (9-2). The shell side outlet of the vacuum membrane module (14) is connected to the hot side inlet of the second heat exchanger (13-2). The hot side outlet of the second heat exchanger (13-2) is connected to the inlet of the third water tank (9-3) via the sixth control valve (3-6). The outlet of the third water tank (9-3) is connected to the vacuum pump (15).

2. The multi-energy complementary vacuum membrane distillation wastewater treatment system according to claim 1, characterized in that: The medium-deep geothermal well group (1) is composed of multiple medium-deep geothermal wells (2) connected in parallel. Each medium-deep geothermal well has a diameter of 100-500 mm and a depth of 1000-4000 m. Coaxial casing and U-shaped pipe are used to realize the heat exchange between liquid water and geothermal energy.

3. The multi-energy complementary vacuum membrane distillation wastewater treatment system according to claim 1, characterized in that: The working fluid used in the above-mentioned vapor compression heat pump (4) is R134a, or R22, or R123.

4. The multi-energy complementary vacuum membrane distillation wastewater treatment system according to claim 1, characterized in that: The vacuum membrane module (14) consists of multiple hollow fiber membrane tubes, each of which is made of polytetrafluoroethylene hydrophobic microporous membrane with a pore size range of 0.1-0.5 μm.

5. The multi-energy complementary vacuum membrane distillation wastewater treatment system according to claim 1, characterized in that: The first water tank (9-1) is used to store softened water, the second water tank (9-2) is used to store industrial wastewater, and the third water tank (9-3) is used to store condensed fresh water.

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