A new energy storage and combined heat and power system based on polygon coaxial tube well

Abstract

The utility model relates to the field of renewable energy cross technology, concretely is a kind of novel energy storage and cogeneration system based on polygon coaxial tube well, including renewable energy power generation device, still including power management unit, heat storage device, energy release unit and control unit;The energy release unit includes low temperature heat pump, high temperature heat pump and organic rankine cycle generator set connected in turn;The heat storage device includes electric boiler and polygon coaxial tube heat storage unit connected in turn;The output end of renewable energy power generation device is connected with electric boiler by power management unit;The system passes through polygon coaxial tube heat storage unit and takes middle deep rock mass as large capacity long time heat storage body, matches with coaxial sleeve pipe circulation to improve heat release efficiency, provides new energy storage path;When releasing energy, through heat pump cascade heating and organic rankine cycle generator set, realize heat cascade utilization and cogeneration, reduce energy loss, improve renewable energy utilization efficiency and economy, support energy system low carbon efficient operation.

Description

Technical Field

[0001] This utility model relates to the field of renewable energy cross-technology, specifically a novel energy storage and combined heat and power system based on a polygonal coaxial well. Background Technology

[0002] Existing renewable energy storage systems suffer from the following problems: On the one hand, they have limited thermal storage capacity and low heat release efficiency. Traditional thermal storage structures are unable to efficiently convert medium-deep rock masses into long-term thermal storage bodies, and the single circulation mode also results in significant energy loss during heat transfer. On the other hand, the lack of a heat cascade utilization mechanism in the energy release stage means that a large amount of waste heat contained in the low-temperature working fluid after power generation is not fully recovered, which not only causes energy waste but also makes it difficult to achieve the coordinated operation of combined heat and power. Ultimately, this leads to low renewable energy utilization efficiency and insufficient economic viability of the entire system, failing to meet the needs of the energy system's transformation towards low-carbon and high-efficiency operation. Utility Model Content

[0003] The purpose of this invention is to provide a novel energy storage and cogeneration system based on a polygonal coaxial well, which addresses the problems of existing renewable energy storage systems, such as limited heat storage capacity, low heat release efficiency, insufficient utilization of medium and deep rock masses, and large heat transfer losses. Furthermore, the lack of cascade utilization during the energy release stage, waste of low-temperature working fluid waste heat, and difficulty in cogeneration result in low system efficiency, poor economic performance, and inability to meet the needs of low-carbon and high-efficiency transformation.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a novel energy storage and combined heat and power system based on a polygonal coaxial tube well, comprising a renewable energy power generation device, a power management unit, a thermal storage device, an energy release unit, and a control unit; the energy release unit comprises a low-temperature heat pump, a high-temperature heat pump, and an organic Rankine cycle generator set connected in sequence; the organic Rankine cycle generator set is connected in parallel with the power management unit; the thermal storage device comprises an electric boiler and a polygonal coaxial tube thermal storage unit connected in sequence; the output end of the renewable energy power generation device is connected to the electric boiler through the power management unit; the outlet of the polygonal coaxial tube thermal storage unit is connected to the inlet of the low-temperature heat pump, the outlet of the low-temperature heat pump is connected to the inlet of the high-temperature heat pump, the outlet of the high-temperature heat pump is connected to the inlet of the organic Rankine cycle generator set, the outlet of the organic Rankine cycle generator set is connected to the inlet of the high-temperature heat pump, the outlet of the high-temperature heat pump is connected to the inlet of the low-temperature heat pump, and the outlet of the low-temperature heat pump is connected to the inlet of the electric boiler and the polygonal coaxial tube thermal storage unit.

[0005] Furthermore, the polygonal coaxial tube thermal storage unit includes a medium-deep geothermal well, a polygonal outer tube and a polygonal coaxial inner tube sequentially nested inside the medium-deep geothermal well from the outside to the inside, and the polygonal outer tube is in contact with the inner wall of the medium-deep geothermal well; the cross-sections of the medium-deep geothermal well, the polygonal outer tube and the polygonal coaxial inner tube are all inverted T-shaped cross-sections.

[0006] Furthermore, the heat storage device also includes a first pipe and a tenth pipe respectively connected to the outlet and inlet of the electric boiler, a first electromagnetic three-way valve connected to the outlet of the first pipe, a third pipe and a second pipe respectively connected to the two outlets of the first electromagnetic three-way valve, a second electromagnetic three-way valve connected to the inlet of the tenth pipe, and an eighth pipe and a ninth pipe connected to the two inlets of the second electromagnetic three-way valve; the outlet of the ninth pipe is connected to the outlet of the polygonal outer pipe; the outlet of the second pipe is connected to the inlet of the polygonal coaxial inner pipe; the outlet of the third pipe is connected to the inlet of the low-temperature heat pump; and the inlet of the eighth pipe is connected to the outlet of the low-temperature heat pump.

[0007] Furthermore, the organic Rankine cycle generator set includes an evaporator, an eleventh pipe connected to the evaporator outlet, a turbine expander connected to the outlet of the eleventh pipe, a generator and a twelfth pipe connected to the output and outlet of the turbine expander respectively, a condenser connected to the outlet of the twelfth pipe, a heating water supply pipe and a heating water return pipe connected to the outlet and inlet of the condenser respectively, and a thirteenth pipe connected to the outlet of the condenser; the outlet of the thirteenth pipe is connected to the inlet of the evaporator.

[0008] Furthermore, the energy release unit also includes a fourth pipe connected to the low-temperature heat pump outlet and the high-temperature heat pump inlet, a seventh pipe connected to the low-temperature heat pump inlet and the high-temperature heat pump outlet, a fifth pipe connected to the high-temperature heat pump outlet, and a sixth pipe connected to the high-temperature heat pump inlet; the outlet of the fifth pipe is connected to the inlet of the evaporator; and the inlet of the sixth pipe is connected to the outlet of the evaporator.

[0009] Furthermore, the power management unit includes an inverter, a transformer, a battery, and a power distribution controller connected in sequence; the power distribution controller is connected in parallel with the electric boiler and the generator.

[0010] Furthermore, the control unit includes variable frequency water pumps respectively installed on the tenth, eighth, seventh, sixth, thirteenth pipelines and the heating return water pipeline sections, and an energy management system electrically connected to the first electromagnetic three-way valve, the second electromagnetic three-way valve and the power distribution controller.

[0011] Furthermore, the renewable energy power generation device includes solar panels and wind turbine generators connected in parallel with the inverter.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0013] This invention relates to a novel energy storage and combined heat and power (CHP) system based on a polygonal coaxial tube well. By integrating renewable energy power generation devices, a power management unit, a thermal storage device, an energy release unit, and a control unit, it forms a highly efficient and synergistic energy utilization system. Utilizing the polygonal coaxial tube thermal storage unit, it uses mid-deep rock masses as a large-capacity, long-term thermal storage medium. Combined with a coaxial casing circulation mode, it improves heat transfer efficiency during the heat release stage, providing a new energy storage technology path for renewable energy power generation. Simultaneously, during the energy release process, through the cascade heating of low-temperature and high-temperature heat pumps and the operation of an organic Rankine cycle generator set, it achieves cascade utilization of the heat in the low-temperature working fluid after power generation, realizing CHP. This significantly reduces energy loss during the energy storage-release process, improves the utilization efficiency and economy of renewable energy, and provides strong support for the low-carbon and high-efficiency operation of the energy system. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the novel energy storage and combined heat and power system based on a polygonal coaxial well according to this utility model.

[0015] Figure 2 This is an enlarged structural schematic diagram of the polygonal coaxial tube thermal storage unit of this utility model.

[0016] In the diagram: 1. Wind turbine generator set; 2. Solar panel; 3. Inverter; 4. Battery; 5. Power distribution controller; 6. Electric boiler; 7. Polygonal coaxial tube thermal storage unit; 8. Low-temperature heat pump; 9. High-temperature heat pump; 10. Organic Rankine cycle generator set; 11. Transformer; 12. First pipeline; 13. Second pipeline; 14. First electromagnetic three-way valve; 15. Third pipeline; 16. Fourth pipeline; 17. Fifth pipeline; 18. Sixth pipeline; 19. Seventh pipeline 20. Eighth Pipeline; 21. Second Solenoid Three-Way Valve; 22. Ninth Pipeline; 23. Tenth Pipeline; 24. Variable Frequency Water Pump; 25. Evaporator; 26. Turbine Expander; 27. Condenser; 28. Generator; 29. ​​Eleventh Pipeline; 30. Twelfth Pipeline; 31. Heating Water Supply Pipeline; 32. Heating Water Return Pipeline; 33. Thirteenth Pipeline; 34. Medium-Deep Geothermal Well; 35. Polygonal Coaxial Inner Pipe; 36. Polygonal Outer Pipe; 37. Energy Management System. Detailed Implementation

[0017] Please see Figure 1-2A novel energy storage and combined heat and power system based on a polygonal coaxial tube well includes a renewable energy power generation device, a power management unit, a thermal storage device, an energy release unit, and a control unit. The energy release unit includes a low-temperature heat pump 8, a high-temperature heat pump 9, and an organic Rankine cycle generator set 10 connected in sequence. The organic Rankine cycle generator set 10 is connected in parallel with the power management unit. The thermal storage device includes an electric boiler 6 and a polygonal coaxial tube thermal storage unit 7 connected in sequence. The output end of the renewable energy power generation device is connected to the electric boiler 6 through the power management unit. The outlet of the polygonal coaxial tube thermal storage unit 7 is connected to the inlet of the low-temperature heat pump 8, the outlet of the low-temperature heat pump 8 is connected to the inlet of the high-temperature heat pump 9, the outlet of the high-temperature heat pump 9 is connected to the inlet of the organic Rankine cycle generator set 10, the outlet of the organic Rankine cycle generator set 10 is connected to the inlet of the high-temperature heat pump 9, the outlet of the high-temperature heat pump 9 is connected to the inlet of the low-temperature heat pump 8, and the outlet of the low-temperature heat pump 8 is connected to the inlet of the electric boiler 6 and the polygonal coaxial tube thermal storage unit 7.

[0018] The polygonal coaxial tube thermal storage unit 7 (approximately 3000m deep) includes a medium-deep geothermal well 34, a polygonal outer tube 36 and a polygonal coaxial inner tube 35 nested sequentially within the medium-deep geothermal well 34 from the outside in. The polygonal outer tube 36 is in contact with the inner wall of the medium-deep geothermal well 34. The cross-sections of the medium-deep geothermal well 34, the polygonal outer tube 36, and the polygonal coaxial inner tube 35 are all inverted T-shaped. The horizontal section of the inverted T-shaped cross-section increases the contact area with the medium-deep rock mass, enhances the efficiency of heat transfer to the rock mass, and increases the thermal storage capacity per unit volume.

[0019] The thermal storage device also includes a first pipe 12 and a tenth pipe 23 connected to the outlet and inlet of the electric boiler 6, respectively; a first electromagnetic three-way valve 14 connected to the outlet of the first pipe 12; a third pipe 15 and a second pipe 13 connected to the two outlets of the first electromagnetic three-way valve 14, respectively; a second electromagnetic three-way valve 21 connected to the inlet of the tenth pipe 23; and an eighth pipe 20 and a ninth pipe 22 connected to the two inlets of the second electromagnetic three-way valve 21. The outlet of the ninth pipe 22 is connected to the outlet of the polygonal outer pipe 36. The outlet of the second pipe 13 is connected to the inlet of the polygonal coaxial inner pipe 35. The outlet of the third pipe 15 is connected to the inlet of the low-temperature heat pump 8. The inlet of the eighth pipe 20 is connected to the outlet of the low-temperature heat pump 8. The hot water generated by the electric boiler 6 enters the polygonal coaxial inner pipe 35 through the first pipe 12, the first electromagnetic three-way valve 14 and the second pipe 13. It works with the polygonal outer pipe 36 to store heat in the underground rock mass. The return water flows back through the ninth pipe 22, the second electromagnetic three-way valve 21 and the tenth pipe 23 to ensure stable heat transfer during the energy storage process. When releasing energy, the first electromagnetic three-way valve 14 switches to the third pipe 15, and the hot water can directly enter the low-temperature heat pump 8. After treatment, it flows back through the eighth pipe 20, the second electromagnetic three-way valve 21 and the tenth pipe 23 to form a complete cycle.

[0020] The organic Rankine cycle generator set 10 includes an evaporator 25, an eleventh pipe 29 connected to the outlet of the evaporator 25, a turbine expander 26 connected to the outlet of the eleventh pipe 29, a generator 28 and a twelfth pipe 30 connected to the output and outlet of the turbine expander 26 respectively, a condenser 27 connected to the outlet of the twelfth pipe 30, a heating water supply pipe 31 and a heating water return pipe 32 connected to the outlet and inlet of the condenser 27 respectively, and a thirteenth pipe 33 connected to the outlet of the condenser 27; the outlet of the thirteenth pipe 33 is connected to the inlet of the evaporator 25. The high-temperature working fluid at 130℃ absorbs heat in the evaporator 25 and then enters the turbine expander 26 through the eleventh pipe 29, driving the generator 28 to generate electricity, thus achieving efficient conversion of thermal energy into electrical energy. After doing work, the organic working fluid enters the condenser 27 through the twelfth pipe 30, and the released waste heat is transported to the heating system through the heating water supply pipe 31. The return water circulates through the heating return water pipe 32, maximizing the utilization of low-grade heat energy. At the same time, the organic working fluid in the condenser 27 flows back to the evaporator 25 through the thirteenth pipe 33 to complete the circulation, reducing working fluid loss.

[0021] The energy release unit also includes a fourth pipe 16 connected to the outlet of the low-temperature heat pump 8 and the inlet of the high-temperature heat pump 9, a seventh pipe 19 connected to the inlet of the low-temperature heat pump 8 and the outlet of the high-temperature heat pump 9, a fifth pipe 17 connected to the outlet of the high-temperature heat pump 9, and a sixth pipe 18 connected to the inlet of the high-temperature heat pump 9; the outlet of the fifth pipe 17 is connected to the inlet of the evaporator 25; and the inlet of the sixth pipe 18 is connected to the outlet of the evaporator 25. The hot water output from the low-temperature heat pump 8 enters the high-temperature heat pump 9 through the fourth pipe 16 for further heating, ensuring that the organic working fluid entering the evaporator 25 has sufficient energy to drive power generation and improve power generation efficiency; the low-temperature working fluid discharged from the evaporator 25 flows back to the high-temperature heat pump 9 through the sixth pipe 18, and then enters the low-temperature heat pump 8 through the seventh pipe 19 for reheating, realizing the recycling of the working fluid and reducing energy loss.

[0022] The power management unit includes an inverter 3, a transformer 11, a battery 4, and a power distribution controller 5 connected in sequence; the power distribution controller 5 is connected in parallel with the electric boiler 6 and the generator 28. The inverter 3 can convert the unstable DC power generated by the solar panel 2 and the wind turbine generator 1 into stable AC power, ensuring the stability of power supply for subsequent equipment; the transformer 11 can accurately regulate voltage to adapt to the power needs of different equipment such as the electric boiler 6 and the generator 28; the power distribution controller 5 realizes intelligent power dispatching, and can reasonably distribute power to the electric boiler 6 for energy storage, transmit it to the grid, or cooperate with the generator 28 to supply power according to actual needs.

[0023] The control unit includes variable frequency water pumps 24 installed on the tenth pipeline 23, the eighth pipeline 20, the seventh pipeline 19, the sixth pipeline 18, the thirteenth pipeline 33, and the heating return water pipeline 32, respectively, and an energy management system (EMS) 37 electrically connected to the first electromagnetic three-way valve 14, the second electromagnetic three-way valve 21, and the power distribution controller 5. The energy management system (EMS) 37 centrally manages the switching of the first electromagnetic three-way valve 14 and the second electromagnetic three-way valve 21 and the energy dispatching of the power distribution controller 5, achieving seamless switching between energy storage and release processes. Simultaneously, it can adaptively adjust operating parameters according to external conditions such as grid load and heating demand, ensuring the system is always in optimal operating condition.

[0024] The renewable energy power generation unit includes solar panels 2 connected in parallel with inverter 3 and a wind turbine generator 1. By naturally complementing solar and wind energy in terms of time and season, the stability and continuity of renewable energy supply are improved, reducing dependence on the traditional power grid.

[0025] Working process and principle: When the system is working, the electrical energy generated by the solar panel 2 and the wind turbine 1 is processed by the inverter 3 and the transformer 11, and then distributed by the power distribution controller 5 to the battery 4 for storage, the power grid, or the electric boiler 6. During the energy storage stage, the first electromagnetic three-way valve 14 switches to the second pipeline 13. The hot water generated by the electric boiler 6 enters the polygonal coaxial inner pipe 35 through the second pipeline 13, flows through the inverted T-shaped structure in the medium-deep geothermal well 34, and the heat is transferred to the surrounding rock mass for storage through the polygonal outer pipe 36. The return water returns to the electric boiler 6 through the ninth pipeline 22, the second electromagnetic three-way valve 21, and the tenth pipeline 23. During the energy release phase, the first electromagnetic three-way valve 14 switches to the third pipeline 15. The heat from the thermal storage rock mass heats the water between the polygonal outer pipe 36 and the inner pipe 35. The 60°C hot water enters the low-temperature heat pump 8 through the third pipeline 15 and is heated to 95°C. It then enters the high-temperature heat pump 9 through the fourth pipeline 16 and is heated to 130°C. Finally, it is sent to the evaporator 25 of the organic Rankine cycle generator set 10 through the fifth pipeline 17. After absorbing heat, the organic working fluid drives the turbine expander 26 to generate electricity through the generator 28. The organic working fluid is condensed by the condenser 27, and the resulting 50°C hot water is used for heating through the heating water supply pipeline 31. The return water is returned through the heating return water pipeline 32. At the same time, 50°C low-temperature water is generated and returns to the evaporator 25 through the thirteenth pipeline 33 to complete the cycle. The water discharged from the evaporator 25 returns to the high-temperature heat pump 9 through the sixth pipeline 18, then enters the low-temperature heat pump 8 through the seventh pipeline 19, and finally flows back through the eighth pipeline 20, the second electromagnetic three-way valve 21, and the tenth pipeline 23. Throughout the process, the Energy Management System (EMS) 37 controls the switching of the first electromagnetic three-way valve 14 and the second electromagnetic three-way valve 21, and adjusts the flow rate in conjunction with the variable frequency water pump 24 to achieve efficient switching between energy storage and energy release, thereby completing the storage of renewable energy and combined heat and power.

[0026] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A novel energy storage and combined heat and power system based on a polygonal coaxial well, comprising a renewable energy power generation device, characterized in that, It also includes a power management unit, a thermal storage device, an energy release unit, and a control unit; the energy release unit includes a low-temperature heat pump (8), a high-temperature heat pump (9), and an organic Rankine cycle generator set (10) connected in sequence; the organic Rankine cycle generator set (10) is connected in parallel with the power management unit; the thermal storage device includes an electric boiler (6) and a polygonal coaxial tube thermal storage unit (7) connected in sequence; the output end of the renewable energy power generation device is connected to the electric boiler (6) through the power management unit; the polygonal coaxial tube thermal storage unit (7) The outlet of 7) is connected to the inlet of the low-temperature heat pump (8), the outlet of the low-temperature heat pump (8) is connected to the inlet of the high-temperature heat pump (9), the outlet of the high-temperature heat pump (9) is connected to the inlet of the organic Rankine cycle generator set (10), the outlet of the organic Rankine cycle generator set (10) is connected to the inlet of the high-temperature heat pump (9), the outlet of the high-temperature heat pump (9) is connected to the inlet of the low-temperature heat pump (8), and the outlet of the low-temperature heat pump (8) is connected to the inlet of the electric boiler (6) and the polygonal coaxial tube heat storage unit (7).

2. The novel energy storage and combined heat and power system according to claim 1, characterized in that, The polygonal coaxial tube thermal storage unit (7) includes a medium-deep geothermal well (34), a polygonal outer tube (36) and a polygonal coaxial inner tube (35) sequentially fitted inside the medium-deep geothermal well (34) from the outside to the inside. The polygonal outer tube (36) is in contact with the inner wall of the medium-deep geothermal well (34). The cross-sections of the medium-deep geothermal well (34), the polygonal outer tube (36) and the polygonal coaxial inner tube (35) are all inverted T-shaped cross-sections.

3. The novel energy storage and combined heat and power system according to claim 2, characterized in that, The heat storage device also includes a first pipeline (12) and a tenth pipeline (23) connected to the outlet and inlet of the electric boiler (6), a first electromagnetic three-way valve (14) connected to the outlet of the first pipeline (12), a third pipeline (15) and a second pipeline (13) connected to the two outlets of the first electromagnetic three-way valve (14), a second electromagnetic three-way valve (21) connected to the inlet of the tenth pipeline (23), and an eighth pipeline (20) and a ninth pipeline (22) connected to the two inlets of the second electromagnetic three-way valve (21). The outlet of the ninth pipeline (22) is connected to the outlet of the polygonal outer pipe (36). The outlet of the second pipeline (13) is connected to the inlet of the polygonal coaxial inner pipe (35). The outlet of the third pipeline (15) is connected to the inlet of the low-temperature heat pump (8). The inlet of the eighth pipeline (20) is connected to the outlet of the low-temperature heat pump (8).

4. The novel energy storage and combined heat and power system according to claim 1, characterized in that, The organic Rankine cycle generator set (10) includes an evaporator (25), an eleventh pipe (29) connected to the outlet of the evaporator (25), a turbine expander (26) connected to the outlet of the eleventh pipe (29), a generator (28) and a twelfth pipe (30) connected to the output and outlet of the turbine expander (26) respectively, a condenser (27) connected to the outlet of the twelfth pipe (30), a heating water supply pipe (31) and a heating water return pipe (32) connected to the outlet and inlet of the condenser (27) respectively, and a thirteenth pipe (33) connected to the outlet of the condenser (27); the outlet of the thirteenth pipe (33) is connected to the inlet of the evaporator (25).

5. The novel energy storage and combined heat and power system according to claim 4, characterized in that, The energy release unit also includes a fourth pipe (16) connected to the outlet of the low-temperature heat pump (8) and the inlet of the high-temperature heat pump (9), a seventh pipe (19) connected to the inlet of the low-temperature heat pump (8) and the outlet of the high-temperature heat pump (9), a fifth pipe (17) connected to the outlet of the high-temperature heat pump (9), and a sixth pipe (18) connected to the inlet of the high-temperature heat pump (9); the outlet of the fifth pipe (17) is connected to the inlet of the evaporator (25); and the inlet of the sixth pipe (18) is connected to the outlet of the evaporator (25).

6. The novel energy storage and combined heat and power system according to claim 4, characterized in that, The power management unit includes an inverter (3), a transformer (11), a battery (4), and a power distribution controller (5) connected in sequence; the power distribution controller (5) is connected in parallel with the electric boiler (6) and the generator (28).

7. The novel energy storage and combined heat and power system according to claim 6, characterized in that, The control unit includes a variable frequency water pump (24) installed on the tenth pipeline (23), the eighth pipeline (20), the seventh pipeline (19), the sixth pipeline (18), the thirteenth pipeline (33), and the heating return water pipeline (32), respectively, and an energy management system (37) electrically connected to the first electromagnetic three-way valve (14), the second electromagnetic three-way valve (21), and the power distribution controller (5).

8. The novel energy storage and combined heat and power system according to claim 6, characterized in that, The renewable energy power generation device includes a solar panel (2) connected in parallel with the inverter (3) and a wind turbine generator (1).

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