A garbage station leachate treatment system and method using solar energy to store heat across seasons

Abstract

The present invention provides a landfill leachate treatment system based on solar energy cross-seasonal heat storage. The system consists of four parts: a wall phase change heat storage and solar thermal collector coupling system, a solar photovoltaic power generation system, a ground source heat pump condenser coupling system, and a landfill leachate treatment system. The phase change heat storage and solar thermal collector coupling system and the ground source heat pump condenser coupling system respectively use solar energy and geothermal energy to heat materials, reducing the heat required for evaporation in the evaporator and the power consumption of the compressor. The electric energy converted by the solar photovoltaic power generation system powers the compressor. The phase change heat storage wall replaces the landfill wall. The solar thermal collector and solar photovoltaic power generation are both located on the roof of the landfill, and the ground source heat pump is located underground in the landfill building, without occupying additional area of ​​the landfill. Renewable clean energy is used to replace traditional fuels and electricity in preheating, material heating, and compressor power supply, maintaining a high degree of compatibility with the operation of the landfill, and achieving low-carbon emissions in the saline wastewater treatment process.

Description

Technical Field

[0001] The invention relates to a garbage station leachate treatment system based on solar energy cross-seasonal heat storage, belonging to the field of low-carbon treatment of saline wastewater. Background Art

[0002] To achieve the national "dual carbon" goals, various industries are actively moving toward low-carbon development. Waste recycling can reduce carbon emissions to a certain extent, but the treatment of leachate from landfill sites still requires electricity, preventing it from achieving true low-carbon treatment. While mechanical vapor recompression technology used in leachate treatment at landfill sites can recover secondary steam and reduce some fresh steam consumption, the actual operation still requires electricity for compressor power consumption and initial steam generation. my country's primary power generation method remains thermal power, and the carbon emissions generated by this electricity consumption are significant. Therefore, it is necessary to design a system that utilizes renewable clean energy as the power source for evaporating saline wastewater from landfill sites. The clean energy used by existing technologies is not sustainable and stable enough to be compatible with the actual operation of landfill sites. Designing a renewable energy source and establishing an energy system for leachate treatment at landfill sites has become a pressing issue.

[0003] Some patents have proposed low-carbon application methods for treating saline wastewater using mechanical vapor recompression technology. For example, patent CN114772674A proposes a low-carbon saline wastewater treatment system and method using solar energy and loop heat pipes. This system uses waste heat from condensed water to preheat the saline wastewater, coupled with a solar heat-absorbing film for heat exchange with the saline wastewater. High-pressure nitrogen is then injected into the condenser section of the loop heat pipe to remove non-condensable gases. The saline wastewater evaporates and absorbs heat in a vacuum environment outside the heat exchange tubes in the condenser section of the loop heat pipe. However, this high-pressure nitrogen injection technology consumes electricity, increasing the system's overall carbon emissions. Furthermore, the system requires additional high-pressure nitrogen injection loop heat pipes, which take up space in the garbage station. The system has high operational requirements and is not very suitable for actual garbage station operations. Patent CN116123544A proposes a low-carbon evaporation system for landfill leachate based on incineration power generation and waste heat heat pumps. The system utilizes mechanical vapor recompression technology to evaporate landfill leachate; the electricity generated by incineration drives equipment within the power system; and the system recovers the high-temperature flue gas waste heat in stages. Incorporating waste heat heat pump technology promotes secondary high-temperature steam compression, saving coal combustion. While the system simultaneously achieves low-carbon evaporation of landfill leachate and the recovery of low-grade waste heat, it cannot avoid the energy consumption of multiple power-consuming devices during the incineration and recovery processes. Furthermore, the complex process of recovering waste heat in stages prevents effective integration with the landfill leachate treatment system.

[0004] The present invention provides a garbage station leachate treatment system based on solar cross-seasonal heat storage. The system consists of four parts: a wall phase change heat storage and solar collector coupling system, a solar photovoltaic power generation system, a ground source heat pump condenser coupling system, and a garbage station leachate treatment system; when solar energy is sufficient, the phase change heat storage and solar collector coupling system and the ground source heat pump condenser coupling system respectively use solar energy and geothermal energy to preheat materials, avoiding the consumption of high-temperature heat energy to preheat materials, reducing the heat required for subsequent evaporation of the evaporator and reducing the power consumption of the compressor; the solar photovoltaic power generation system converts and stores electricity to directly power the compressor, without generating additional compressor power consumption; even when solar energy is insufficient, the system can use the previously stored heat and electricity to maintain the normal operation of the system, realizing cross-seasonal heat storage and supply Energy; the phase change heat storage wall, solar photovoltaic power generation, solar collector, ground source heat pump, etc. adopted in the present invention are cleverly combined with the garbage station house. The phase change heat storage wall replaces the original garbage station wall, the solar collector and solar photovoltaic power generation are both located on the roof of the garbage station, and the ground source heat pump is located under the garbage station house. The combination of the several and the garbage station house does not occupy additional area of ​​the garbage station; and renewable clean energy is used to replace traditional fuel and electricity in the three aspects of preheating, material heating and compressor power supply, which continuously and stably provides power source for the leachate treatment system of the garbage station, while maintaining a high degree of adaptability with the actual operation of the garbage station, reducing the overall carbon emissions of the system, and having strong usability, truly realizing low-carbon emissions in the saline wastewater treatment process. Summary of the Invention

[0005] The purpose of the present invention is to provide a garbage station leachate treatment system based on solar energy cross-seasonal heat storage. The present invention is conducive to promoting the application of low-carbon technology in the field of using thermal methods to evaporate saline wastewater.

[0006] The embodiment of the present application provides a garbage station leachate treatment system based on solar cross-seasonal heat storage, which consists of four parts: a wall phase change heat storage and solar collector coupling system, a solar photovoltaic power generation system, a ground source heat pump condenser coupling system, and a garbage station leachate treatment system;

[0007] The wall phase change heat storage and solar thermal collector coupling system includes a first water inlet 1-1, a second water inlet 1-2, a first solar thermal collector 2-1, a second solar thermal collector 2-2, a first water pipe 3-1, a second water pipe 3-2, a first phase change wall 4-1, a second phase change wall 4-2, a first heat storage wall 5-1, a second heat storage wall 5-2, a first stop valve 6-1, a second stop valve 6-2, and a third stop valve 6-3; the first water inlet 1-1 is located at the left edge of the roof and is connected to the water inlet of the first solar thermal collector 2-1, the second water inlet 1-2 is located at the right edge of the roof and is connected to the second solar thermal collector 2-2, the first solar thermal collector 2-1 is located on the left side of the garbage station roof, and the second solar thermal collector 2-2 is located on the right side of the garbage station roof, the first water pipe 3-1 is connected to the water outlet of the first solar thermal collector 2-1 and is located directly below it, the second water pipe 3-2 is connected to the second solar thermal collector 2 -2 is connected to and located directly below the water outlet of the first phase change wall 4-1, the first phase change wall 4-1 and the first heat storage wall 5-1 are located on the left side of the house, the first phase change wall 4-1 is located outside the first heat storage wall 5-1, the first water pipe 3-1 passes through the first phase change wall 4-1, the second phase change wall 4-2 and the second heat storage wall 5-2 are located on the right side of the house, the second phase change wall 4-2 is located outside the second heat storage wall 5-2, the second water pipe 3-2 passes through the second phase change wall 4-2, the first stop valve 6-1 and the second stop valve 6-2 are located directly below the first phase change wall 4-1 and the second phase change wall 4-2, the first stop valve 6-1 and the second stop valve 6-2 are located on the first water pipe 3-1 and the second water pipe 3-2, the third stop valve 6-3 is located between the first stop valve 6-1 and the second stop valve 6-2, and the inlet of the third stop valve 6-3 is connected to the outlet of the first stop valve 6-1 and the second stop valve 6-2 respectively;

[0008] The solar photovoltaic power generation system includes a photovoltaic panel 11, a battery pack 12, and a fourth shut-off valve 6-4. The photovoltaic panel 11 is located at the center of the roof. The battery pack 12 is connected to the photovoltaic panel 11 and is located to the lower left thereof. The fourth shut-off valve 6-4 is located directly below the battery pack 12. The battery pack 12 is electrically connected to the compressor 13 via the fourth shut-off valve 6-4.

[0009] The ground source heat pump condenser coupling system includes a first compressor 7, a condenser 8, an expansion valve 9, and a ground source heat pump 10; the first inlet 8-1 of the condenser 8 is connected to the outlet of the first compressor 7, the inlet of the expansion valve 9 is connected to the first outlet 8-3 of the condenser 8, the outlet of the expansion valve 9 is connected to the inlet of the ground source heat pump 10, the inlet of the first compressor 7 is connected to the outlet of the ground source heat pump 10, and the outlet of the third stop valve 6-3 is connected to the inlet of the first compressor 7;

[0010] The leachate treatment system of the garbage station includes a feed pump 19, a preheating water tank 18, a plate heat exchanger 17, a capillary tube 16, a horizontal falling film evaporator 15, a gas-liquid separator 14, a compressor 13, a condensate pump 21, a circulating pump 22, a crystallization device 23, a discharge pump 24, a circulating water pump 25, and a condensate tank 20; the outlet of the feed pump 19 is connected to the inlet of the preheating water tank 18, the outlet of the preheating water tank 18 is connected to the first inlet 17-1 of the plate heat exchanger 17, the first outlet 17-3 of the plate heat exchanger 17 is connected to the first inlet 15-1 of the horizontal falling film evaporator 15, the first outlet 15-5 of the horizontal falling film evaporator 15 is connected to the second inlet 8-2 of the condenser 8, the second outlet 8-4 of the condenser 8 is connected to the inlet of the gas-liquid separator 14, the outlet of the gas-liquid separator 14 is connected to the inlet of the compressor 13, the outlet of the compressor 13 is connected to the third inlet 15-3 of the horizontal falling film evaporator 15, and the horizontal falling film evaporator 1 The second outlet 15-6 is connected to the inlet of the circulating water pump 25, which is connected to the second inlet 15-2 of the horizontal falling film evaporator 15. The third outlet 15-7 of the horizontal falling film evaporator 15 is connected to the inlet of the circulating pump 22, which is connected to the fourth inlet 15-4 of the horizontal falling film evaporator 15. The fourth outlet 15-8 of the horizontal falling film evaporator 15 is connected to the inlet of the condensate pump 21, which is connected to the second inlet 17-2 of the plate heat exchanger 17. The circulating pump 22 is located below the condensate pump 21. The fifth outlet 15-9 of the horizontal falling film evaporator 15 is connected to the inlet of the discharge pump 24, which is connected to the inlet of the crystallization device 23. The second outlet 17-4 of the plate heat exchanger 17 is connected to the capillary tube 16 and the condensate tank 20, respectively. The outlet of the capillary tube 16 is connected to the pipeline between the compressor 13 and the third inlet 15-3 of the horizontal falling film evaporator 15.

[0011] The pipes in the system are all made of metal pipes, and thermal insulation materials are laid on the outside of the pipes.

[0012] In the system, phase change heat storage walls are used on the left and right sides of the building wall. The material is paraffin-based PCM composite material. The phase change heat storage walls are respectively a first phase change wall 4-1, a second phase change wall 4-2, a first heat storage wall 5-1, and a second heat storage wall 5-2. After absorbing solar energy, the first water pipe 3-1 and the second water pipe 3-2 located in the first phase change wall 4-1 and the second phase change wall 4-2 are preheated, and the residual heat is stored in the first heat storage wall 5-1 and the second heat storage wall 5-2, respectively. When the heat in the first phase change wall 4-1 and the second phase change wall 4-2 is insufficient to preheat the first water pipe 3-1 and the second water pipe 3-2, the first heat storage wall 5-1 and the second heat storage wall 5-2 respectively provide heat.

[0013] In the system, the first solar collector 2-1 and the second solar collector 2-2 are made of graphene-enhanced polymer composite materials, the photovoltaic panel 11 is made of crystalline silicon, and the battery pack 12 is made of electrodes and electrolyte, the electrodes are made of lead and its oxides, and the electrolyte is sulfuric acid solution.

[0014] In the system, the photovoltaic panels 11 absorb solar energy on sunny days, convert it into electrical energy, and transmit it to the battery pack 12 for storage. When the system is running, it provides power to the compressor 13. The battery pack 12 uses lead-acid batteries VRLA.

[0015] The ground source heat pump 10 in the system is composed of a heat pump unit and a group of underground heat exchangers buried underground. The underground heat exchangers are polybutylene pipes or high-density polyethylene pipes.

[0016] The horizontal falling film evaporator 15 in the system is mainly composed of an evaporator shell, internal pipes and a spray device; liquid flows through the pipes, and the spray device sprays the liquid into droplets, which turn into secondary steam outside the pipes.

[0017] In the system, the flow of the wall phase change heat storage and solar collector coupling system is controlled by adjusting the first stop valve 6-1 and the second stop valve 6-2 respectively, the flow of the ground source heat pump condenser coupling system is controlled by the third stop valve 6-3, and the power delivered to the compressor 13 is controlled by the fourth stop valve 6-4.

[0018] In the system, the system consists of four parts: a wall phase change heat storage and solar collector coupling system, a solar photovoltaic power generation system, a ground source heat pump condenser coupling system, and a garbage station leachate treatment system; the medium in the wall phase change heat storage and solar collector coupling system is room temperature water, which enters the system from the first water inlet 1-1 and the second water inlet 1-2 respectively, and after the end, the medium temperature water enters the ground source heat pump condenser coupling system through the third stop valve 6-3; the medium of the ground source heat pump condenser coupling system is medium temperature water, which enters the system through the third stop valve 6-3, and after the end, the low temperature and low pressure water returns to the ground source heat pump 10; the medium of the garbage station leachate treatment system is saline wastewater, which enters the system through the feed pump 19, and after the end, the solid waste residue is discharged through the crystallization device 23 and landfilled; the medium of the solar photovoltaic power generation system is solar energy, which enters the system through the photovoltaic panel 11, and the converted electrical energy is transported to the compressor 13 through the fourth stop valve 6-4.

[0019] The medium in the wall phase change heat storage and solar collector coupling system in the system is room temperature water, the medium in the solar photovoltaic power generation system is electricity, the medium in the ground source heat pump condenser coupling system is medium temperature water, and the medium in the garbage station leachate treatment system is saline wastewater.

[0020] The present invention discloses a garbage station leachate treatment system based on solar cross-seasonal heat storage, which includes the following processes during operation:

[0021] There are two overall operating modes of the system. The first operating mode is direct operation on sunny days. Normal temperature water enters the corresponding first solar collector 2-1 and second solar collector 2-2 from the first water inlet 1-1 and the second water inlet 1-2 respectively to be heated, and then enters the first water pipe 3-1 and the second water pipe 3-2 corresponding to the first phase change wall 4-1 and the second phase change wall 4-2 respectively to continue to be heated, and then respectively passes through the first stop valve 6-1 and the second stop valve 6-2 to merge and then enter the first compressor 7 through the third stop valve 6-3 to be heated, and then enters the condenser 8 through the first inlet 8-1 of the condenser 8; at the same time, the salt-containing wastewater passes The wastewater enters the preheating water tank 18 through the feed pump 19, is preheated in the preheating water tank 18, and then enters the plate heat exchanger 17 through the first inlet 17-1 of the plate heat exchanger 17 for heat exchange. Then, it exits from the first outlet 17-3 of the plate heat exchanger 17, enters the horizontal falling film evaporator 15 through the first inlet 15-1 of the horizontal falling film evaporator 15, and then enters the condenser 8 through the first outlet 15-5 of the horizontal falling film evaporator 15 and the second inlet 8-2 of the condenser 8 to exchange heat with the high-temperature water inside, thereby increasing the temperature of the salty wastewater to generate secondary steam, which passes through the second outlet 8-4 of the condenser 8 and then enters the gas-liquid separator 14 for gas-liquid separation. The gas enters the compressor The temperature and pressure of the steam in 13 are increased to become superheated steam, and then the steam is mixed with the low-temperature condensed water in the capillary tube to form a saturated state. The steam enters the horizontal falling film evaporator through the third inlet 15-3 of the horizontal falling film evaporator 15 and exchanges heat with the saline wastewater to form high-temperature condensed water. The saline wastewater entering the horizontal falling film evaporator 15 finally falls into the water tank at the bottom of the horizontal falling film evaporator 15, and is pressurized by the circulating pump 22 and the circulating water pump 25 respectively, and enters the spray device of the horizontal falling film evaporator 15 through the second inlet 15-2 of the horizontal falling film evaporator 15 and the fourth inlet 15-4 of the horizontal falling film evaporator 15 to evaporate again. The high-temperature condensed water is pressurized by the condensate pump 21 and flows into the plate type The heat exchanger 17 exchanges heat with the saline wastewater, and the cooled condensed water is respectively passed into the capillary 16 and the condensed water tank 20. After the two evaporations are completed, the concentrated wastewater is pressurized and discharged by the discharge pump 24 and then enters the crystallization device 23. At the same time, the high-temperature water in the condenser 8 is cooled and enters the expansion valve 9 through the first outlet 8-3 of the condenser 8 to reduce the pressure to low-temperature and low-pressure water, and then enters the ground source heat pump 10 to be heated and merged with the outlet water of the third stop valve (6-3), and enters the first compressor (7) to form a cycle; the photovoltaic power generation panel 11 absorbs solar energy and converts it into electrical energy, which is stored in the battery pack 12 and transported to the compressor 13 through the fourth stop valve 6-4;

[0022] The second operation mode is operation after energy storage: when the system is not in operation, solar energy is absorbed by the first phase change wall 4-1 and the second phase change wall 4-2, and the converted heat energy is stored in the first heat storage wall 5-1 and the second heat storage wall 5-2; when solar energy is insufficient, the first heat storage wall 5-1 and the second heat storage wall 5-2 respectively supply heat to the first water pipe 3-1 and the second water pipe 3-2 corresponding to the first phase change wall 4-1 and the second phase change wall 4-2, and normal temperature water enters the corresponding first solar collector 2-1 and the second solar collector 2-2 from the first water inlet 1-1 and the second water inlet 1-2, and then enters the first water pipe 3-1 corresponding to the first phase change wall 4-1 and the second phase change wall 4-2 respectively. The wastewater is heated in the second water pipe 3-2, and then respectively passes through the first stop valve 6-1 and the second stop valve 6-2, and then enters the first compressor 7 through the third stop valve 6-3 to be heated, and then enters the condenser 8 through the first inlet 8-1 of the condenser 8; at the same time, the salt-containing wastewater enters the preheating water tank 18 through the feed pump 19, is preheated in the preheating water tank 18, and then enters the plate heat exchanger 17 through the first inlet 17-1 of the plate heat exchanger 17 for heat exchange, and then exits from the first outlet 17-3 of the plate heat exchanger 17, enters the horizontal falling film evaporator 15 through the first inlet 15-1 of the horizontal falling film evaporator 15, and then enters the horizontal falling film evaporator 15 through the first outlet 15-5 of the horizontal falling film evaporator 15 and the second inlet 8-2 of the condenser 8 in sequence. The condenser 8 exchanges heat with the high-temperature water inside, raising the temperature of the salt-containing wastewater to generate secondary steam, which passes through the second outlet 8-4 of the condenser 8 and then enters the gas-liquid separator 14 to separate the gas and liquid. The gas enters the compressor 13 to increase the temperature and pressure to become superheated steam, and then transfers heat with the low-temperature condensed water in the capillary tube to mix into a saturated state, and enters the evaporator through the third inlet 15-3 of the horizontal falling film evaporator 15 to exchange heat with the salt-containing wastewater to form high-temperature condensed water. The salt-containing wastewater entering the horizontal falling film evaporator 15 finally falls into the water tank at the bottom of the horizontal falling film evaporator 15, and is pressurized by the circulating pump 22 and the circulating water pump 25 respectively, and passes through the second inlet 15-2 of the horizontal falling film evaporator 15 and the fourth inlet 15-4 of the horizontal falling film evaporator 15 to enter the horizontal falling film evaporator 15. The spray device of the evaporator 15 evaporates again, and the high-temperature condensed water is pressurized by the condensate pump 21 and flows into the plate heat exchanger 17 to exchange heat with the saline wastewater. The cooled part of the condensed water is respectively passed into the capillary 16 and the condensate tank 20. After the two evaporations are completed, the concentrated wastewater is pressurized and discharged by the discharge pump 24 and then enters the crystallization device 23; at the same time, the high-temperature water in the condenser 8 is cooled and enters the expansion valve 9 through the first outlet 8-3 of the condenser 8 to reduce the pressure to low-temperature and low-pressure water, and then enters the ground source heat pump 10 to heat up and merge with the outlet water of the third stop valve 6-3, and enters the first compressor 7 to form a cycle; the photovoltaic panel 11 absorbs solar energy and converts it into electrical energy, which is stored in the battery pack 12 and transported to the compressor 13 through the fourth stop valve 6-4. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] AttachmentFigure 1 This is a schematic diagram of the present invention.

[0024] Attachment Figure 1 The reference numbers in the figure are: first water inlet 1-1, second water inlet 1-2, first solar thermal collector 2-1, second solar thermal collector 2-2, first water pipe 3-1, second water pipe 3-2, first phase change wall 4-1, second phase change wall 4-2, first heat storage wall 5-1, second heat storage wall 5-2, first stop valve 6-1, second stop valve 6-2, third stop valve 6-3, fourth stop valve 6-4, first compressor 7, condenser 8, expansion valve 9, ground source heat pump 10, photovoltaic panel 11, battery pack 12, compressor 13, gas-liquid separator 14, horizontal falling film evaporator 15, capillary tube 16, plate heat exchanger 17, preheated water tank 18, feed pump 19, condensate water tank 20, condensate water pump 21, circulation pump 22, crystallization device 23, discharge pump 24, circulation water pump 25, garbage station house 26.

[0025] Attachment Figure 2 Schematic diagram of the inlet and outlet of the plate heat exchanger 17.

[0026] Attachment Figure 2 The reference numerals in the figure are: first inlet 17 - 1 of plate heat exchanger 17 , second inlet 17 - 2 of plate heat exchanger 17 , first outlet 17 - 3 of plate heat exchanger 17 , second outlet 17 - 4 of plate heat exchanger 17 .

[0027] Attachment Figure 3 Schematic diagram of the inlet and outlet of condenser 8.

[0028] Attachment Figure 3 The reference numerals in the figure are: first inlet 8-1 of condenser 8, second inlet 8-2 of condenser 8, first outlet 8-3 of condenser 8, second outlet 8-4 of condenser 8.

[0029] Attachment Figure 4 It is a schematic diagram of the inlet and outlet of the horizontal falling film evaporator 15.

[0030] Attachment Figure 4 The reference numerals in the figure are as follows: first inlet 15-1 of horizontal falling film evaporator 15, second inlet 15-2 of horizontal falling film evaporator 15, third inlet 15-3 of horizontal falling film evaporator 15, fourth inlet 15-4 of horizontal falling film evaporator 15, first outlet 15-5 of horizontal falling film evaporator 15, second outlet 15-6 of horizontal falling film evaporator 15, third outlet 15-7 of horizontal falling film evaporator 15, fourth outlet 15-8 of horizontal falling film evaporator 15, and fifth outlet 15-9 of horizontal falling film evaporator 15. DETAILED DESCRIPTION

[0031] like Figure 1As shown, a landfill leachate treatment system based on solar cross-seasonal heat storage mainly includes a first water inlet 1-1, a second water inlet 1-2, a first solar thermal collector 2-1, a second solar thermal collector 2-2, a first water pipe 3-1, a second water pipe 3-2, a first phase change wall 4-1, a second phase change wall 4-2, a first heat storage wall 5-1, a second heat storage wall 5-2, a first stop valve 6-1, a second stop valve 6-2, and a third stop valve. Valve 6-3, fourth stop valve 6-4, first compressor 7, condenser 8, expansion valve 9, ground source heat pump 10, photovoltaic panel 11, battery pack 12, compressor 13, gas-liquid separator 14, horizontal falling film evaporator 15, capillary tube 16, plate heat exchanger 17, preheating water tank 18, feed pump 19, condensate water tank 20, condensate water pump 21, circulating pump 22, crystallization device 23, discharge pump 24, circulating water pump 25, garbage station house 26.

[0032] Take the treatment of saline wastewater as an example. The overall operation mode of the system is divided into two types. The first operation mode is direct operation on sunny days. Normal temperature water enters the corresponding first solar collector 2-1 and second solar collector 2-2 from the first water inlet 1-1 and the second water inlet 1-2 respectively to be heated, and then enters the first water pipe 3-1 and the second water pipe 3-2 corresponding to the first phase change wall 4-1 and the second phase change wall 4-2 respectively to continue to be heated, and then respectively passes through the first stop valve 6-1 and the second stop valve 6-2 to merge and enter the first compressor 7 through the third stop valve 6-3 to be heated, and then enters the condenser 8 through the first inlet 8-1 of the condenser 8; at the same time, the saline wastewater The wastewater enters the preheating water tank 18 through the feed pump 19, is preheated in the preheating water tank 18, and then enters the plate heat exchanger 17 through the first inlet 17-1 of the plate heat exchanger 17 for heat exchange, and then exits from the first outlet 17-3 of the plate heat exchanger 17, enters the horizontal falling film evaporator 15 through the first inlet 15-1 of the horizontal falling film evaporator 15, and then enters the condenser 8 through the first outlet 15-5 of the horizontal falling film evaporator 15 and the second inlet 8-2 of the condenser 8 to exchange heat with the high-temperature water inside, thereby increasing the temperature of the salt-containing wastewater to generate secondary steam, which passes through the second outlet 8-4 of the condenser 8 and then enters the gas-liquid separator 14 for gas-liquid separation, and the gas enters the compressor The temperature and pressure in the compressor 13 are increased to become superheated steam, which is then mixed with the low-temperature condensate in the capillary tube to form a saturated state. The steam enters the horizontal falling film evaporator through the third inlet 15-3 of the horizontal falling film evaporator 15 and exchanges heat with the saline wastewater to form high-temperature condensate. The saline wastewater entering the horizontal falling film evaporator 15 finally falls into the water tank at the bottom of the horizontal falling film evaporator 15, is pressurized by the circulating pump 22 and the circulating water pump 25 respectively, and enters the horizontal falling film evaporator 15 spray device through the second inlet 15-2 and the fourth inlet 15-4 of the horizontal falling film evaporator 15 to evaporate again. The above steps are repeated, and the high-temperature condensate is The condensate pump 21 pressurizes the water and flows it into the plate heat exchanger 17 for heat exchange with the saline wastewater. After cooling, part of the condensate is respectively passed into the capillary 16 and the condensate tank 20. After two evaporations are completed, the concentrated wastewater is pressurized and discharged by the discharge pump 24 and then enters the crystallization device 23. At the same time, the high-temperature water in the condenser 8 is cooled and enters the expansion valve 9 through the first outlet 8-3 of the condenser 8 to reduce the pressure to low-temperature and low-pressure water, and then enters the ground source heat pump 10 to heat up and merge through the third stop valve 6-3, and the above process is repeated. The photovoltaic panel 11 absorbs solar energy and converts it into electrical energy, which is stored in the battery pack 12 and then transported to the compressor 13 through the fourth stop valve 6-4.

[0033] The second operation mode is operation after energy storage: when the system is not in operation, solar energy is absorbed by the first phase change wall 4-1 and the second phase change wall 4-2, and the converted heat energy is stored in the first heat storage wall 5-1 and the second heat storage wall 5-2; when solar energy is insufficient, the first heat storage wall 5-1 and the second heat storage wall 5-2 respectively supply heat to the first water pipe 3-1 and the second water pipe 3-2 corresponding to the first phase change wall 4-1 and the second phase change wall 4-2, and normal temperature water enters the corresponding first solar collector 2-1 and the second solar collector 2-2 from the first water inlet 1-1 and the second water inlet 1-2, and then enters the first water pipe 3-1 corresponding to the first phase change wall 4-1 and the second phase change wall 4-2 respectively. The wastewater is heated in the second water pipe 3-2, and then respectively passes through the first stop valve 6-1 and the second stop valve 6-2, and then enters the first compressor 7 through the third stop valve 6-3 to be heated, and then enters the condenser 8 through the first inlet 8-1 of the condenser 8; at the same time, the salt-containing wastewater enters the preheating water tank 18 through the feed pump 19, is preheated in the preheating water tank 18, and then enters the plate heat exchanger 17 through the first inlet 17-1 of the plate heat exchanger 17 for heat exchange, and then exits from the first outlet 17-3 of the plate heat exchanger 17, enters the horizontal falling film evaporator 15 through the first inlet 15-1 of the horizontal falling film evaporator 15, and then enters the horizontal falling film evaporator 15 through the first outlet 15-5 of the horizontal falling film evaporator 15 and the second inlet 8-2 of the condenser 8 in sequence. The condenser 8 exchanges heat with the high-temperature water inside, raising the temperature of the salt-containing wastewater to generate secondary steam, which passes through the second outlet 8-4 of the condenser 8 and then enters the gas-liquid separator 14 to separate the gas and liquid. The gas enters the compressor 13 to increase the temperature and pressure to become superheated steam, and is mixed with the low-temperature condensed water in the capillary tube to form a saturated state. It enters the evaporator through the third inlet 15-3 of the horizontal falling film evaporator 15 to exchange heat with the salt-containing wastewater to form high-temperature condensed water. The salt-containing wastewater entering the horizontal falling film evaporator 15 finally falls into the water tank at the bottom of the horizontal falling film evaporator 15, and is pressurized by the circulating pump 22 and the circulating water pump 25 respectively, and passes through the second inlet 15-2 of the horizontal falling film evaporator 15 and the fourth inlet 15-4 of the horizontal falling film evaporator 15 to enter the horizontal falling film evaporator 15. The spray device of the evaporator 15 evaporates again, and the above steps are repeated. The high-temperature condensed water is pressurized by the condensate pump 21 and flows into the plate heat exchanger 17 to exchange heat with the saline wastewater. The cooled part of the condensed water is respectively passed into the capillary 16 and the condensate tank 20. After the two evaporations are completed, the concentrated wastewater pressurized and discharged by the discharge pump 24 then enters the crystallization device 23; at the same time, the high-temperature water in the condenser 8 is cooled and enters the expansion valve 9 through the first outlet 8-3 of the condenser 8 to reduce the pressure to low-temperature and low-pressure water, and then enters the ground source heat pump 10 to heat up and merge through the third stop valve 6-3, and the above process is repeated; the photovoltaic panel 11 absorbs solar energy and converts it into electrical energy, which is stored in the battery pack 12 and transported to the compressor 13 through the fourth stop valve 6-4.

[0034] This low-carbon operation system of the garbage station leachate treatment system based on solar cross-seasonal heat storage, when solar energy is sufficient, the phase change heat storage and solar collector coupling system, the ground source heat pump condenser coupling system respectively use solar energy and geothermal energy to heat materials, avoid consuming high-temperature heat energy to preheat materials, reduce the heat required for subsequent evaporation of the evaporator and reduce the power consumption of the compressor; the solar photovoltaic power generation system converts the stored electricity to directly power the compressor, without generating additional compressor power consumption; even when solar energy is insufficient, the system can use the previously stored heat and electricity to maintain the normal operation of the system, realizing cross-seasonal heat storage and energy supply; the phase change heat storage wall, Solar photovoltaic power generation, solar thermal collectors, ground-source heat pumps, etc. are cleverly combined with the garbage station buildings. Phase change heat storage walls replace the original garbage station walls. Solar thermal collectors and solar photovoltaic power generation are both located on the roof of the garbage station, and the ground-source heat pump is located underground in the garbage station building. The combination of these and the garbage station building does not occupy additional area of ​​the garbage station. Renewable clean energy is used to replace traditional fuel and electricity in the three aspects of preheating, material heating and compressor power supply, providing a continuous and stable power source for the garbage station leachate treatment system. While maintaining a high degree of adaptability with the actual operation of the garbage station, it reduces the overall carbon emissions of the system, has strong usability, and truly achieves low-carbon emissions in the saline wastewater treatment process.

Claims

1. A garbage station leachate treatment system based on solar cross-seasonal heat storage, characterized by: It consists of four parts: wall phase change heat storage and solar collector coupling system, solar photovoltaic power generation system, ground source heat pump condenser coupling system, and garbage station leachate treatment system. The wall phase change heat storage and solar thermal collector coupling system comprises a first water inlet (1-1), a second water inlet (1-2), a first solar thermal collector (2-1), a second solar thermal collector (2-2), a first water pipe (3-1), a second water pipe (3-2), a first phase change wall (4-1), a second phase change wall (4-2), a first heat storage wall (5-1), a second heat storage wall (5-2), a first stop valve (6-1), a second stop valve (6-2), and a third stop valve (6-3); the first water inlet (1-1) is located at the left edge of the roof and is connected to the water inlet of the first solar thermal collector (2-1). The second water inlet (1-2) is located at the right edge of the roof and is connected to the second solar thermal collector (2-2). The first solar thermal collector (2-1) is located on the left side of the roof of the garbage station, and the second solar thermal collector (2-2) is located on the right side of the roof of the garbage station. The first water pipe (3-1) is connected to the water outlet of the first solar thermal collector (2-1) and is located directly below it. The second water pipe (3-2) is connected to the outlet of the second solar thermal collector (2-2). The water outlet is connected and located directly below the water outlet. The first phase change wall (4-1) and the first heat storage wall (5-1) are located on the left side of the house. The first phase change wall (4-1) is located outside the first heat storage wall (5-1). The first water pipe (3-1) passes through the first phase change wall (4-1). The second phase change wall (4-2) and the second heat storage wall (5-2) are located on the right side of the house. The second phase change wall (4-2) is located outside the second heat storage wall (5-2). The second water pipe (3-2) passes through the second phase change wall (4-2). The first stop valve (6-1) and the second stop valve (6-2) are respectively located directly below the first phase change wall (4-1) and the second phase change wall (4-2); the first stop valve (6-1) and the second stop valve (6-2) are respectively located on the first water supply pipe (3-1) and the second water supply pipe (3-2); the third stop valve (6-3) is located between the first stop valve (6-1) and the second stop valve (6-2); the inlet of the third stop valve (6-3) is respectively connected to the outlet of the first stop valve (6-1) and the outlet of the second stop valve (6-2); The solar photovoltaic power generation system comprises a photovoltaic power generation panel (11), a battery pack (12), and a fourth shut-off valve (6-4); the photovoltaic power generation panel (11) is located at the center of the roof, the battery pack (12) is connected to the photovoltaic power generation panel (11) and is located at the lower left thereof, the fourth shut-off valve (6-4) is located directly below the battery pack (12), and the battery pack (12) is electrically connected to the compressor (13) via the fourth shut-off valve (6-4); The ground source heat pump condenser coupling system comprises a first compressor (7), a condenser (8), an expansion valve (9), and a ground source heat pump (10); a first inlet (8-1) of the condenser (8) is connected to the outlet of the first compressor (7), an inlet of the expansion valve (9) is connected to the first outlet (8-3) of the condenser (8), an outlet of the expansion valve (9) is connected to the inlet of the ground source heat pump (10), the inlet of the first compressor (7) is connected to the outlet of the ground source heat pump (10), and the outlet of the third stop valve (6-3) is connected to the inlet of the first compressor (7); The garbage station leachate treatment system includes a feed pump (19), a preheating water tank (18), a plate heat exchanger (17), a capillary tube (16), a horizontal falling film evaporator (15), a gas-liquid separator (14), a compressor (13), a condensing water pump (21), a circulating pump (22), a crystallization device (23), a discharge pump (24), a circulating water pump (25), and a condensing water tank (20); the outlet of the feed pump (19) is connected to the inlet of the preheating water tank (18), and the outlet of the preheating water tank (18) is connected to the first inlet (17-1) of the plate heat exchanger (17). The first outlet (17-3) of the plate heat exchanger (17) is connected to the first inlet (15-1) of the horizontal falling film evaporator (15), the first outlet (15-5) of the horizontal falling film evaporator (15) is connected to the second inlet (8-2) of the condenser (8), the second outlet (8-4) of the condenser (8) is connected to the inlet of the gas-liquid separator (14), the outlet of the gas-liquid separator (14) is connected to the inlet of the compressor (13), the outlet of the compressor (13) is connected to the third inlet (15-3) of the horizontal falling film evaporator (15), and the horizontal falling film evaporator The second outlet (15-6) of (15) is connected to the inlet of the circulating water pump (25), the outlet of the circulating water pump (25) is connected to the second inlet (15-2) of the horizontal falling film evaporator (15), the third outlet (15-7) of the horizontal falling film evaporator (15) is connected to the inlet of the circulating pump (22), the outlet of the circulating pump (22) is connected to the fourth inlet (15-4) of the horizontal falling film evaporator (15), the fourth outlet (15-8) of the horizontal falling film evaporator (15) is connected to the inlet of the condensate pump (21), and the outlet of the condensate pump (21) is connected to the plate heat exchanger. The horizontal falling film evaporator (15) is connected to the second inlet (17-2) of the heat exchanger (17), the circulation pump (22) is located below the condensate pump (21), the fifth outlet (15-9) of the horizontal falling film evaporator (15) is connected to the inlet of the discharge pump (24), the outlet of the discharge pump (24) is connected to the inlet of the crystallization device (23), the second outlet (17-4) of the plate heat exchanger (17) is connected to the capillary tube (16) and the condensate tank (20), respectively, and the outlet of the capillary tube (16) is connected to the pipeline between the compressor (13) and the third inlet (15-3) of the horizontal falling film evaporator (15).

2. The garbage station leachate treatment system based on solar cross-seasonal heat storage according to claim 1 is characterized by: Phase change heat storage walls are used on the left and right sides of the building wall. The material is paraffin-based PCM composite material. The phase change heat storage walls are respectively a first phase change wall (4-1), a second phase change wall (4-2), a first heat storage wall (5-1), and a second heat storage wall (5-2). After absorbing solar energy, the first water pipe (3-1) and the second water pipe (3-2) located in the first phase change wall (4-1) and the second phase change wall (4-2) are preheated, and the residual heat is stored in the first heat storage wall (5-1) and the second heat storage wall (5-2). When the heat in the first phase change wall (4-1) and the second phase change wall (4-2) is insufficient to preheat the first water pipe (3-1) and the second water pipe (3-2), the first heat storage wall (5-1) and the second heat storage wall (5-2) respectively provide heat.

3. The garbage station leachate treatment system based on solar cross-seasonal heat storage according to claim 1 is characterized by: The first solar thermal collector (2-1) and the second solar thermal collector (2-2) are made of graphene-enhanced polymer composite materials, the photovoltaic power generation panel (11) is made of crystalline silicon, and the battery pack (12) is composed of electrodes and electrolyte, the electrodes are made of lead and its oxide, and the electrolyte is a sulfuric acid solution.

4. The garbage station leachate treatment system based on solar cross-seasonal heat storage according to claim 1 is characterized by: The photovoltaic panel (11) absorbs solar energy on sunny days and converts it into electrical energy, which is then transferred to the battery pack (12) for storage. When the system is running, it provides electrical energy for the compressor (13). The battery pack (12) uses lead-acid batteries (VRLA).

5. The garbage station leachate treatment system based on solar cross-seasonal heat storage according to claim 1 is characterized by: The ground source heat pump (10) is composed of a heat pump unit and a group of underground heat exchangers buried underground. The underground heat exchangers are polybutylene pipes or high-density polyethylene pipes.

6. The garbage station leachate treatment system based on solar cross-seasonal heat storage according to claim 1 is characterized by: The medium in the wall phase change heat storage and solar collector coupling system is room temperature water, the medium in the solar photovoltaic power generation system is electricity, the medium in the ground source heat pump condenser coupling system is medium temperature water, and the medium in the garbage station leachate treatment system is saline wastewater.

7. The garbage station leachate treatment system based on solar cross-seasonal heat storage according to claim 1 is characterized by: The horizontal falling film evaporator (15) is mainly composed of an evaporator shell, internal pipes and a spraying device; liquid flows through the pipes, and the spraying device sprays the liquid into droplets, which are converted into secondary steam outside the pipes.

8. The method for operating a garbage station leachate treatment system based on solar cross-seasonal heat storage according to claim 1, characterized in that: The overall operation mode of the system is divided into two types. The first operation mode is direct operation on sunny days. Normal temperature water enters the corresponding first solar collector (2-1) and second solar collector (2-2) from the first water inlet (1-1) and the second water inlet (1-2) respectively to be heated, and then enters the first water pipe (3-1) and the second water pipe (3-2) corresponding to the first phase change wall (4-1) and the second phase change wall (4-2) respectively to continue to be heated, and then respectively passes through the first stop valve (6-1) and the second stop valve (6-2) and then merges and enters the first compressor (7) through the third stop valve (6-3) to be heated, and then enters the condenser (8) through the first inlet (8-1) of the condenser (8); at the same time, the salt-containing wastewater passes through The feed pump (19) enters the preheating water tank (18), is preheated in the preheating water tank (18), and then enters the plate heat exchanger (17) through the first inlet (17-1) of the plate heat exchanger (17) for heat exchange, then exits from the first outlet (17-3) of the plate heat exchanger (17), enters the horizontal falling film evaporator (15) through the first inlet (15-1) of the horizontal falling film evaporator (15), and then enters the condenser (8) through the first outlet (15-5) of the horizontal falling film evaporator (15) and the second inlet (8-2) of the condenser (8) in turn to exchange heat with the high-temperature water inside, thereby increasing the temperature of the salt-containing wastewater to generate secondary steam, which passes through the second outlet (8-4) of the condenser (8) and then enters the gas-liquid separator (14) for gas-liquid separation. The gas enters the compressor (13) and is heated and pressurized to become superheated steam, and then is mixed with the low-temperature condensed water in the capillary tube to form a saturated state. The gas enters the horizontal falling film evaporator (15) through the third inlet (15-3) of the horizontal falling film evaporator (15) and exchanges heat with the saline wastewater to form high-temperature condensed water. The saline wastewater entering the horizontal falling film evaporator (15) finally falls into the bottom water tank of the horizontal falling film evaporator (15), and is pressurized by the circulating pump (22) and the circulating water pump (25) respectively, and enters the horizontal falling film evaporator (15) through the second inlet (15-2) and the fourth inlet (15-4) of the horizontal falling film evaporator (15) to be evaporated again. The high-temperature condensed water is pressurized by the condensation water pump (21) and flows into the horizontal falling film evaporator (15) spray device. The plate heat exchanger (17) exchanges heat with the salty wastewater, and the cooled condensed water is respectively passed into the capillary tube (16) and the condensed water tank (20). After the two evaporations are completed, the concentrated wastewater is pressurized and discharged by the discharge pump (24) and then enters the crystallization device (23); at the same time, the high-temperature water in the condenser (8) is cooled and enters the expansion valve (9) through the first outlet (8-3) of the condenser (8) to reduce the pressure to low-temperature and low-pressure water, and then enters the ground source heat pump (10) to heat up and merge with the outlet water of the third stop valve (6-3), and enters the first compressor (7) to form a cycle; the photovoltaic power generation panel (11) absorbs solar energy and converts it into electrical energy, which is stored in the battery pack (12) and is transported to the compressor (13) through the fourth stop valve (6-4); The second operation mode is operation after energy storage: when the system is not in operation, solar energy is absorbed by the first phase change wall (4-1) and the second phase change wall (4-2), and the converted heat energy is stored in the first heat storage wall (5-1) and the second heat storage wall (5-2); when the solar energy is insufficient, the first heat storage wall (5-1) and the second heat storage wall (5-2) respectively provide heat to the first water pipe (3-1) and the second water pipe (3-2) corresponding to the first phase change wall (4-1) and the second phase change wall (4-2), and normal temperature water enters the corresponding first solar collector (2-1) and the second solar collector (2-2) from the first water inlet (1-1) and the second water inlet (1-2), and then enters The first phase change wall (4-1) and the second phase change wall (4-2) are heated in the first water pipe (3-1) and the second water pipe (3-2) respectively, and then respectively pass through the first stop valve (6-1) and the second stop valve (6-2) to merge and then pass through the third stop valve (6-3) to enter the first compressor (7) to be heated, and then enter the condenser (8) through the first inlet (8-1) of the condenser (8); at the same time, the salt-containing wastewater enters the preheating water tank (18) through the feed pump (19), is preheated in the preheating water tank (18), and then enters the plate heat exchanger (17) through the first inlet (17-1) of the plate heat exchanger (17) for heat exchange, and then exits from the first outlet (17-3) of the plate heat exchanger (17). The wastewater enters the horizontal falling film evaporator (15) through the first inlet (15-1) of the horizontal falling film evaporator (15), and then enters the condenser (8) through the first outlet (15-5) of the horizontal falling film evaporator (15) and the second inlet (8-2) of the condenser (8) to exchange heat with the high-temperature water inside, thereby increasing the temperature of the saline wastewater to generate secondary steam, which then passes through the second outlet (8-4) of the condenser (8) and enters the gas-liquid separator (14) to separate the gas and liquid. The gas enters the compressor (13) to increase the temperature and pressure to become superheated steam, which then transfers heat with the low-temperature condensed water in the capillary tube and mixes into a saturated state. The wastewater enters the evaporator through the third inlet (15-3) of the horizontal falling film evaporator (15) to exchange heat with the saline wastewater to form high-temperature condensed water. The salty wastewater entering the horizontal falling film evaporator (15) finally falls into the bottom water tank of the horizontal falling film evaporator (15), and is pressurized by the circulating pump (22) and the circulating water pump (25) respectively through the second inlet (15-2) of the horizontal falling film evaporator (15) and the fourth inlet (15-4) of the horizontal falling film evaporator (15) to enter the spray device of the horizontal falling film evaporator (15) for further evaporation. The high-temperature condensed water is pressurized by the condensate pump (21) and flows into the plate heat exchanger (17) to exchange heat with the salty wastewater. The cooled condensed water is respectively passed into the capillary (16) and the condensate tank (20). After the two evaporations are completed, the concentrated wastewater pressurized and discharged by the discharge pump (24) then enters the crystallization device (23);At the same time, the high-temperature water in the condenser (8) cools down and enters the expansion valve (9) through the first outlet (8-3) of the condenser (8) to reduce the pressure to low-temperature, low-pressure water. It then enters the ground source heat pump (10) to heat up and merges with the outlet water of the third stop valve (6-3). It then enters the first compressor (7) to form a cycle. The photovoltaic power generation panel (11) absorbs solar energy and converts it into electrical energy, which is stored in the battery pack (12) and then transported to the compressor (13) through the fourth stop valve (6-4).

9. The method for operating a garbage station leachate treatment system based on solar cross-seasonal heat storage according to claim 8, characterized in that: By adjusting the first stop valve (6-1) and the second stop valve (6-2), the flow rates of the wall phase change heat storage and solar collector coupling systems are respectively controlled; the third stop valve (6-3) controls the flow rate of the ground source heat pump condenser coupling system; and the fourth stop valve (6-4) controls the amount of electricity delivered to the compressor (13).

10. The method for operating a garbage station leachate treatment system based on solar cross-seasonal heat storage according to claim 9, characterized in that: The system consists of four parts: a wall phase change heat storage and solar thermal collector coupling system, a solar photovoltaic power generation system, a ground source heat pump condenser coupling system, and a garbage station leachate treatment system. The medium in the wall phase change heat storage and solar thermal collector coupling system is room temperature water, which enters the system from the first water inlet (1-1) and the second water inlet (1-2) respectively. After the completion, the medium temperature water enters the ground source heat pump condenser coupling system through the third stop valve (6-3); the medium in the ground source heat pump condenser coupling system is medium temperature water, which enters the system through the third stop valve (6-3). After the completion, the low temperature and low pressure water returns to the ground source heat pump (10); the medium in the garbage station leachate treatment system is saline wastewater, which enters the system through the feed pump (19). After the completion, the solid waste residue is discharged through the crystallization device (23) and landfilled; the medium in the solar photovoltaic power generation system is electric energy. Solar energy enters the system through the photovoltaic power generation panel (11). The converted electric energy is transported to the compressor (13) through the fourth stop valve (6-4).

Images