Combined solar and geothermal energy driven building heating and fresh water production energy supply system

Abstract

A building heating and freshwater production system driven by a combination of solar and geothermal energy belongs to the field of ecological and environmental protection. The system includes a solar collector module, a geothermal module, a heat pump module, a vacuum membrane distillation module, and a building heating module. Its key feature is the use of liquid water as the working fluid. When solar radiation is abundant, the liquid water directly enters the solar collector array to absorb the heat generated by solar radiation, and after being heated, it enters the radiators inside the building to provide heat. Simultaneously, a heat pump extracts underground heat energy through a medium-deep geothermal heat exchange pipe to heat industrial wastewater, which is then used to produce freshwater through the vacuum membrane distillation module. When solar radiation is insufficient, underground heat energy is extracted through the heat pump and the medium-deep geothermal heat exchange pipe to provide heat to the building. This invention, through the complementary driving of solar and geothermal energy, simultaneously realizes the building heating and industrial wastewater freshwater production process, possessing advantages such as high energy efficiency, low operating costs, and strong stability. It can be applied to industrial heating, HVAC, and wastewater treatment.

Description

Technical Field

[0001] This invention relates to a building heating and freshwater production energy supply system driven by a combination of solar and geothermal energy, belonging to the field of energy conservation and environmental protection. Background Technology

[0002] Northwest China has a dry and cold climate, and is rich in clean and environmentally friendly renewable energy sources such as solar and geothermal energy. These are currently mainly used in the HVAC (Heating, Ventilation, and Air Conditioning) sector, with good results. Common renewable energy utilization technologies include solar thermal energy collection and geothermal-heat pump technology. Solar thermal energy collection converts solar radiation into heat energy through solar collectors for user consumption; while geothermal-heat pump technology extracts heat energy from underground soil and rock layers through geothermal heat exchange pipes and further improves the quality of the heat energy for user consumption. In recent years, more researchers have attempted to combine solar and geothermal energy technologies to meet the winter heating needs of buildings through multi-energy complementarity, significantly reducing building energy consumption. However, problems such as a single energy supply target and unstable operation exist, requiring further in-depth research.

[0003] Vacuum membrane distillation is a novel wastewater treatment technology, mainly composed of a vacuum membrane module, a circulating pump, a feed tank, a condensate tank, and other components. The vacuum membrane module consists of multiple hollow fiber membrane tubes. It primarily uses a hydrophobic microporous membrane as the mass transfer barrier and the vapor pressure difference across the membrane as the driving force for mass transfer, achieving evaporation separation and purification of solution wastewater. It offers advantages such as mild operating conditions and high separation efficiency. However, current systems are susceptible to membrane fouling, temperature and concentration polarization, and the lack of latent heat recovery devices, generally exhibiting poor thermodynamic performance and high energy consumption, thus limiting its industrial application.

[0004] Therefore, utilizing solar energy, geothermal energy, and vacuum membrane distillation technology to meet the winter heating energy needs of buildings, while simultaneously recycling and treating wastewater to achieve freshwater production, is of great value and significance for improving energy efficiency, promoting green and low-carbon technologies, and maintaining global ecological security. Summary of the Invention

[0005] This invention proposes a building heating and freshwater production energy supply system and method driven by a combination of solar and geothermal energy, which features low energy consumption and high stability.

[0006] A building heating and freshwater production energy supply system driven by a combination of solar and geothermal energy is characterized by mainly comprising: a solar collector module, a heat pump module, a geothermal energy module, a vacuum membrane distillation module, a building heating module, a first control valve to a twelfth control valve, a first water tank to a third water tank, a first circulation pump to a fourth circulation pump, a vacuum pump, a condensate tank, and a cooler. The solar collector module consists of multiple all-glass vacuum tube solar collectors; the heat pump module consists of an evaporator, a compressor, a condenser, and a throttling valve; the geothermal energy module consists of a medium-deep geothermal heat exchange tube and a geothermal stratum; the vacuum membrane distillation module consists of multiple vacuum membrane distillation components and a heat exchanger; and the building heating module consists of multiple radiators and the target heating building.

[0007] The outlet of the first water tank is connected to the inlet of the first circulating pump via the first control valve. The outlet of the first circulating pump is divided into two paths: one path is connected to the inlet of the all-glass vacuum tube solar collector via the second control valve, and the outlet of the all-glass vacuum tube solar collector is connected to the inlet of the radiator in the target heating building via the third control valve; the other path is connected to the cold side inlet of the condenser in the heat pump module via the fourth control valve, and the cold side outlet of the condenser is connected to the inlet of the radiator in the target heating building via the fifth control valve. The outlet of the radiator is connected to the top inlet of the first water tank.

[0008] The outlet of the second water tank is connected to the inlet of the second circulating pump via the sixth control valve. The outlet of the second circulating pump is connected to the inlet of the medium-deep geothermal heat exchange tube via the seventh control valve. The outlet of the medium-deep geothermal heat exchange tube is connected to the hot-side inlet of the evaporator in the heat pump module via the eighth control valve. The hot-side outlet of the evaporator is connected to the top inlet of the second water tank. The cold-side inlet of the evaporator is connected to the throttle valve. The cold-side outlet of the evaporator is connected to the compressor inlet. The compressor outlet is connected to the hot-side inlet of the condenser. The hot-side outlet of the condenser is connected to the throttle valve.

[0009] The outlet of the third water tank is connected to the inlet of the third circulation pump via the ninth control valve. The outlet of the third circulation pump is connected to the cold side inlet of the condenser in the heat pump module. The cold side outlet of the condenser is connected to the hot side inlet of the heat exchanger via the tenth control valve. The hot side outlet of the heat exchanger is connected to the top inlet of the third water tank. One of the cold side inlets of the heat exchanger is connected to the feed liquid inlet via the eleventh control valve, and the other is connected to the solution outlet of the vacuum membrane distillation component. The cold side outlet of the heat exchanger is connected to the inlet of the fourth circulation pump. The outlet of the fourth circulation pump is connected to the solution inlet of the vacuum membrane distillation component. The steam outlet of the vacuum membrane distillation component is connected to the hot side inlet of the cooler. The hot side outlet of the cooler is connected to the top inlet of the condensate tank. The cold side of the cooler is connected to the cooling circulating water. The top outlet of the condensate tank is connected to the inlet of the vacuum pump via the twelfth control valve. The outlet of the vacuum pump is open to the atmosphere.

[0010] The above-mentioned building heating and freshwater production energy supply system driven by a combination of solar and geothermal energy is characterized in that: the solar collector module is composed of multiple all-glass vacuum tube solar collectors connected in series.

[0011] The above-mentioned building heating and freshwater production energy supply system driven by a combination of solar and geothermal energy is characterized in that: the medium-deep geothermal heat exchange pipe adopts a casing type, with a drilling depth of 500m-3000m, an inner pipe diameter of 100-200mm, and an outer pipe diameter of 200-300mm.

[0012] The above-mentioned building heating and freshwater production energy supply system driven by a combination of solar and geothermal energy is characterized in that the working fluid used in the heat pump module is R134a, or R22, or R123, or R142b, or R410A.

[0013] The above-mentioned building heating and freshwater production energy supply system driven by solar and geothermal energy is characterized in that: the above-mentioned vacuum membrane distillation module is composed of multiple vacuum membrane distillation components connected in parallel, each vacuum membrane distillation component is composed of multiple hollow fiber membrane tubes, each membrane tube is made of polytetrafluoroethylene hydrophobic microporous evaporation membrane with a pore size of 0.1-0.45μm and a porosity of 20%-85%.

[0014] The above-mentioned building heating and freshwater production and energy supply system driven by combined solar and geothermal energy is characterized in that: the first water tank, the second water tank, and the third water tank are all used to store softened water, and the condensate tank is used to store freshwater produced by distillation through a vacuum membrane distillation module.

[0015] The working method of the above-mentioned building heating and freshwater production and energy supply system driven by combined solar and geothermal energy is as follows:

[0016] First, a certain volume of softened water is stored in each of the first to third water tanks;

[0017] (1) When the solar radiation intensity is sufficient, a building heating and freshwater production mode driven by a combination of solar energy and geothermal energy is adopted;

[0018] The first control valve, the second control valve, the third control valve, and the first circulation pump are opened. The softened water in the first water tank enters the solar collector module under the drive of the first circulation pump. The all-glass vacuum tube solar collector absorbs solar energy and heats the softened water. The heated softened water enters the radiator inside the target building through the third control valve to supply heat to the target building.

[0019] Simultaneously, the eleventh control valve is opened, filling the vacuum membrane distillation module with a certain amount of industrial wastewater. Then, the sixth, seventh, eighth, tenth, and twelfth control valves, as well as the second, third, and fourth circulation pumps and the vacuum pump, are opened. Softened water from the second water tank, driven by the second circulation pump, enters the deep underground rock heat exchange tube, absorbing thermal energy from the deep underground rock. After its temperature rises, it enters the hot side of the evaporator in the heat pump module through the eighth control valve, transferring heat to the refrigerant on the cold side of the evaporator. The refrigerant absorbs heat and evaporates into a gaseous state, entering the compressor for compression, temperature increase, and pressure boosting. It then enters the hot side of the condenser, condensing and releasing heat to the softened water on the cold side. After condensation, the refrigerant enters the evaporator after pressure reduction and throttling through the expansion valve, continuing its circulation and evaporation. Meanwhile, the softened water from the third water tank, driven by the third circulation pump, enters... The wastewater enters the condenser on the cold side to absorb heat, then enters the heat exchanger on the hot side via the tenth control valve to heat the wastewater to be treated, and then returns to the third water tank. The wastewater in the vacuum membrane distillation module enters the heat exchanger on the cold side to absorb heat under the drive of the fourth circulation pump. After the temperature rises, it returns to the tube side of the vacuum membrane distillation module. The shell side of the vacuum membrane distillation module is kept under a certain negative pressure under the suction of the vacuum pump, creating a certain pressure difference on both sides of the hydrophobic membrane of the vacuum membrane module. Water molecules in the main wastewater solution in the tube side of the vacuum membrane distillation module migrate to the hot side membrane surface, absorb heat and evaporate into water vapor molecules. Driven by the transmembrane pressure difference, the water vapor molecules reach the shell side vacuum side, and then enter the cooler for cooling and cooling. Finally, they are collected in the form of liquid water in the condensate tank. The concentrate in the tube side of the vacuum membrane distillation module continues to circulate and evaporate. After reaching the required concentration, it is recycled and reused, thus completing the freshwater production process.

[0020] (2) When the solar radiation intensity is insufficient and the ambient temperature is low, a building heating mode driven by geothermal energy shall be adopted;

[0021] The system cannot utilize solar energy for heating; due to increased building heating demand, the system must prioritize using a medium-deep geothermal energy-heat pump system for building heating; The first, fourth, fifth, sixth, seventh, and eighth control valves, as well as the first and second circulation pumps, are opened. Softened water from the second water tank, driven by the second circulation pump, enters the medium-deep geothermal heat exchange pipe, absorbing underground medium-deep geothermal energy. After its temperature rises, it enters the hot side of the evaporator in the heat pump module through the eighth control valve, transferring heat to the refrigerant on the cold side of the evaporator. The refrigerant absorbs heat and evaporates into a gaseous state, entering the compressor for compression, temperature increase, and pressure boosting. It then enters the hot side of the condenser to condense and release heat to the softened water on the cold side. After condensation, the refrigerant enters the throttling valve for pressure reduction and then enters the evaporator to continue circulating and evaporating. Softened water from the first water tank, driven by the first circulation pump, enters the cold side of the condenser to absorb heat. After absorbing heat, the softened water enters the radiators inside the target building through the fifth control valve, supplying heat to the target building. Attached Figure Description

[0022] Figure 1 This invention proposes a building heating and freshwater production energy supply system and method driven by a combination of solar and geothermal energy.

[0023] The following are the labels in the diagram: 1. Solar collector module, 2. Solar collector, 3. Heat pump module, 4. Evaporator, 5. Compressor, 6. Condenser, 7. Throttling valve, 8. Geothermal energy module, 9. Medium-deep geothermal heat exchange pipe, 10. Geothermal strata, 11. Vacuum membrane distillation module, 12. Vacuum membrane distillation assembly, 13. Heat exchanger, 14. Building heating module, 15. Radiator, 16. Target heating building, 17-1-17-12 First control valve to twelfth control valve, 18-1-18-3 First water tank to third water tank, 19-1-19-4 First circulation pump to fourth circulation pump, 20. Vacuum pump, 21. Condensate tank, 22. Cooler. Detailed Implementation

[0024] Figure 1 This invention proposes a building heating and freshwater production energy supply system and method driven by a combination of solar and geothermal energy. See below for reference. Figure 1 Describe the specific working process of this technology.

[0025] The device operates as follows:

[0026] First, a certain volume of softened water is stored in the first water tank 18-1 to the third water tank 18-3.

[0027] (1) When the solar radiation intensity is sufficient, a building heating and freshwater production mode driven by a combination of solar energy and geothermal energy is adopted;

[0028] Open the first control valve 17-1, the second control valve 17-2, the third control valve 17-3 and the first circulation pump 19-1. The softened water in the first water tank 18-1 enters the solar collector module 1 under the drive of the first circulation pump 19-1. The all-glass vacuum tube solar collector 2 absorbs solar energy and heats the softened water. The heated softened water enters the radiator 15 inside the target building 16 through the third control valve 17-3 to supply heat to the target building 16.

[0029] Simultaneously, the eleventh control valve 17-11 is opened, filling the vacuum membrane distillation module 11 with a certain amount of industrial wastewater. Then, the sixth control valve 17-6, seventh control valve 17-7, eighth control valve 17-8, tenth control valve 17-10, and twelfth control valve 17-12 are opened, along with the second circulation pump 19-2, third circulation pump 19-3, fourth circulation pump 19-4, and vacuum pump 20. Softened water from the second water tank 18-2 enters the medium-deep... The geothermal heat exchanger 9 absorbs thermal energy from the deep underground rock layers. After its temperature rises, it enters the hot side of the evaporator 4 in the heat pump module 3 via the eighth control valve 17-8, transferring heat to the refrigerant on the cold side of the evaporator 4. The refrigerant absorbs heat and evaporates into a gaseous state, then enters the compressor 5 for compression, temperature increase, and pressure increase. It then enters the condenser 6 on the hot side to release heat to the softened water on the cold side. After condensation, the refrigerant enters the throttling valve 7 for pressure reduction and throttling before entering the evaporator 4 to continue circulating and evaporating. Meanwhile, the third water tank 18-3 contains... Softened water enters the cold side of condenser 6 under the drive of the third circulation pump 19-3 to absorb heat, and then enters the hot side of heat exchanger 13 through the tenth control valve 17-10 to heat the wastewater to be treated, and then returns to the third water tank 18-3. The wastewater in vacuum membrane distillation module 12 enters the cold side of heat exchanger 13 under the drive of the fourth circulation pump 19-4 to absorb heat. After the temperature rises, it returns to the tube side of vacuum membrane distillation module 12. The shell side of vacuum membrane distillation module 12 is kept under a certain negative pressure state under the suction of vacuum pump 20, which creates a certain pressure difference on both sides of the hydrophobic membrane of vacuum membrane module. Water molecules in the main wastewater solution in the tube side of vacuum membrane distillation module 12 migrate to the hot side membrane surface, absorb heat and evaporate into water vapor molecules. The water vapor molecules reach the shell side vacuum side under the drive of the transmembrane pressure difference, and then enter the cooler 22 for cooling and cooling. Finally, it is collected in the form of liquid water in condensate tank 21. The concentrate in the tube side of vacuum membrane distillation module 12 continues to circulate and evaporate. After reaching the required concentration, it is recycled and reused, thus completing the freshwater production process.

[0030] (2) When the solar radiation intensity is insufficient and the ambient temperature is low, a building heating mode driven by geothermal energy shall be adopted;

[0031] The system cannot utilize solar energy for heating; due to increased building heating demand, the system must prioritize using a medium-deep geothermal energy-heat pump system for building heating; opening the first control valve 17-1, the fourth control valve 17-4, the fifth control valve 17-5, the sixth control valve 17-6, the seventh control valve 17-7, the eighth control valve 17-8, the first circulation pump 19-1, and the second circulation pump 19-2, the softened water in the second water tank 18-2 enters the medium-deep geothermal heat exchange pipe 9 driven by the second circulation pump 19-2, absorbs underground medium-deep geothermal energy, and after the temperature rises, enters through the eighth control valve 17-8... The heat pump module 3 enters the heat pump module 3. The heat pump module 3 transfers heat to the heat pump module 4. The heat pump module 4 transfers heat to the heat pump module 4. The heat pump module 4 absorbs heat and evaporates into a gaseous state. The heat pump module 5 is then compressed and heated and pressurized. The heat pump module 6 enters the heat pump module 6 and releases heat to the heat pump module 6. The heat pump module 6 then enters the heat pump module 7 and enters the heat pump module 4 to continue circulating and evaporating. The heat pump module 6 absorbs heat and enters the heat pump module 7 to enter the heat pump module 4 to supply heat to the heat pump module 16. The heat pump module 6 transfers heat to the heat pump module 4. The heat pump module 6 transfers heat to the heat pump module 4. The heat pump module 6 transfers heat to the heat pump module 4. The heat pump module 4 ...

[0032] Although the specific implementation process of the present invention has been described in detail above with reference to the accompanying drawings, this is not intended to limit the present invention. Those skilled in the art should understand that all variations and improvements made within the spirit and principles of the present invention and under the guidance of the present invention are within the scope of protection of the present invention.

Claims

1. A building heating and freshwater production energy supply system driven by a combination of solar and geothermal energy, characterized in that... In The main components include: a solar thermal collector module (1), a heat pump module (3), a geothermal energy module (8), a vacuum membrane distillation module (11), a building heating module (14), a first control valve to a twelfth control valve (17-1-17-12), a first water tank to a third water tank (18-1-18-3), a first circulation pump to a fourth circulation pump (19-1-19-4), a vacuum pump (20), a condensate tank (21), and a cooler (22). The solar thermal collector module ( 1) Composed of multiple all-glass vacuum tube solar collectors (2), heat pump module (3) composed of evaporator (4), compressor (5), condenser (6) and throttle valve (7), geothermal energy module (8) composed of medium-deep geothermal heat exchange tube (9) and geothermal layer (10), vacuum membrane distillation module (11) composed of multiple vacuum membrane distillation components (12) and heat exchanger (13), building heating module (14) composed of multiple radiators (15) and target building (16); The outlet of the first water tank (18-1) is connected to the inlet of the first circulating pump (19-1) via the first control valve (17-1). The outlet of the first circulating pump (19-1) is divided into two paths. One path is connected to the inlet of the all-glass vacuum tube solar collector (2) via the second control valve (17-2). The outlet of the all-glass vacuum tube solar collector (2) is connected to the inlet of the radiator (15) in the target building (16) via the third control valve (17-3). The other path is connected to the cold side inlet of the condenser (6) in the heat pump module (3) via the fourth control valve (17-4). The cold side outlet of the condenser (6) is connected to the inlet of the radiator (15) in the target building (16) via the fifth control valve (17-5). The outlet of the radiator (15) is connected to the top inlet of the first water tank (18-1). The outlet of the second water tank (18-2) is connected to the inlet of the second circulation pump (19-2) via the sixth control valve (17-6). The outlet of the second circulation pump (19-2) is connected to the inlet of the medium-deep geothermal heat exchange tube (9) via the seventh control valve (17-7). The outlet of the medium-deep geothermal heat exchange tube (9) is connected to the hot side inlet of the evaporator (4) inside the heat pump module (3) via the eighth control valve (17-8). The hot side outlet of the evaporator (4) is connected to the top inlet of the second water tank (18-2). The cold side inlet of the evaporator (4) is connected to the throttle valve (7). The cold side outlet of the evaporator (4) 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 (6). The hot side outlet of the condenser (6) is connected to the throttle valve (7). The outlet of the third water tank (18-3) is connected to the inlet of the third circulation pump (19-3) via the ninth control valve (17-9). The outlet of the third circulation pump (19-3) is connected to the cold-side inlet of the condenser (6) inside the heat pump module (3). The cold-side outlet of the condenser (6) is connected to the hot-side inlet of the heat exchanger (13) via the tenth control valve (17-10). The hot-side outlet of the heat exchanger (13) is connected to the top inlet of the third water tank (18-3). One of the cold-side inlets of the heat exchanger (13) is connected to the feed liquid inlet via the eleventh control valve (17-11), and the other is connected to the vacuum membrane distillation assembly (…). 12) Solution outlet, the cold side outlet of heat exchanger (13) is connected to the inlet of the fourth circulation pump (19-4), the outlet of the fourth circulation pump (19-4) is connected to the solution inlet of vacuum membrane distillation assembly (12), the steam outlet of vacuum membrane distillation assembly (12) is connected to the hot side inlet of cooler (22), the hot side outlet of cooler (22) is connected to the top inlet of condensate tank (21), the cold side of cooler (22) is connected to cooling circulating water, the top outlet of condensate tank (21) is connected to the inlet of vacuum pump (20) via the twelfth control valve (17-12), and the outlet of vacuum pump (20) is connected to the atmosphere.

2. The building heating and fresh water production energy supply system driven by solar energy and geothermal energy in combination according to claim 1, characterized in that: The solar thermal collector module (1) is composed of multiple all-glass vacuum tube solar collectors (2) connected in series.

3. The building heating and fresh water production energy supply system driven by solar energy and geothermal energy in combination according to claim 1, characterized in that: The medium-deep geothermal heat exchanger (9) is a casing type, with a drilling depth of 500m-3000m, an inner tube diameter of 100-200mm, and an outer tube diameter of 200-300mm.

4. The building heating and fresh water production energy supply system driven by solar energy and geothermal energy in combination according to claim 1, characterized in that: The working fluid used in the above heat pump module (3) is R134a, or R22, or R123, or R142b, or R410A.

5. The building heating and fresh water production energy supply system driven by solar energy and geothermal energy in combination according to claim 1, characterized in that: The vacuum membrane distillation module (11) is composed of multiple vacuum membrane distillation components (12) connected in parallel. Each vacuum membrane distillation component (12) is composed of multiple hollow fiber membrane tubes. Each membrane tube is made of polytetrafluoroethylene hydrophobic microporous evaporation membrane with a pore size of 0.1-0.45μm and a porosity of 20%-85%.

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