Multi-energy coupling heating system and heating and heat storage method thereof

Abstract

The multi-energy coupling heating system comprises a geothermal energy utilization module, an air energy utilization module, a solar energy utilization module, an energy storage tank, a control module and the like, and multi-loop cooperation is formed through a pipeline and a circulating pump. The method comprises a winter heating mode and a summer heat storage mode, wherein geothermal energy is used as a basis in winter, solar energy is used for auxiliary heating, and air energy is used for supplementary heating; solar energy is utilized to store heat underground in summer to maintain soil heat balance. And the solar PV / T assembly generates power to be used by system equipment and stores the power. Multi-energy complementation is achieved, the energy self-sufficiency rate is increased, cost is reduced, carbon emission is reduced, stable operation under extreme working conditions is guaranteed, and the system is suitable for rural heating in the northwest region.

Description

Technical Field

[0001] The present invention relates to the technical field of clean energy heating, and in particular to a multi-energy coupling heating system and a heating and heat storage method thereof. Background Art

[0002] As a major energy consumer and emitter, the heating sector has clearly required a significant increase in the proportion of renewable energy in heating, gradually replacing loose coal and high-energy-consuming traditional heating methods, and encouraging multi-energy complementarity to break through the limitations of single clean energy technology.

[0003] However, using a single clean energy source for heating still faces significant challenges. Shallow geothermal energy has high initial investment, and the cost of buried pipe engineering accounts for a large proportion. Limited by soil thermal properties, hydrogeological conditions, and available site area, its applicability is limited in areas with hard rock, limited underground space, or poor soil thermal conductivity. There is also the risk of imbalance between cold and hot loads. In areas where heating is the primary source of heat, long-term heating may cause soil temperature to drop year by year, reducing system energy efficiency and necessitating additional heating measures. Air-source heat pumps (air energy) experience low-temperature performance degradation. When ambient temperatures fall below -10°C, heating capacity and energy efficiency drop significantly, especially in the extremely cold northern regions. Heating needs must be met with increased energy consumption. Evaporators are prone to frost in low-temperature, high-humidity environments, and frequent defrosting interrupts heating and consumes additional energy. Solar thermal systems are significantly affected by day and night, season, and weather, and are intermittent and unstable, unable to provide a continuous and stable heat source. Large-capacity heat storage or auxiliary heat sources are required. Furthermore, in cold seasons, solar radiation is weak, daylight is short, and heat collection efficiency is low, which conflicts with peak heating demand.

[0004] The above-mentioned problems of single clean energy technology make it difficult to efficiently meet the actual needs of rural heating in the northwest region. It is urgent to break through the technical and economic bottlenecks through multi-energy coupling. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides a multi-energy coupling heating system and a heating and heat storage method thereof.

[0006] The present invention discloses a multi-energy coupling heating system, comprising:

[0007] The geothermal energy utilization module includes a geothermal heat exchanger and a geothermal heat pump unit. The geothermal heat exchanger is connected to the geothermal heat pump unit through a geothermal side circulation pipeline to form a geothermal side circulation loop; the geothermal heat pump unit is also connected to the user side through a user side circulation pipeline to form a heating loop;

[0008] An air energy utilization module, comprising an air source heat pump unit, wherein the air source heat pump unit and the ground source heat pump unit are connected in parallel to the heating circuit to provide supplementary heating for the user side;

[0009] A solar energy utilization module includes a solar PT component and a solar PV / T component. The solar PT component is connected to a first coil heat exchanger in an energy storage tank via a first heat energy circulation pipeline to form a first heat energy circulation loop; the solar PV / T component is connected to a second coil heat exchanger in the energy storage tank via a second heat energy circulation pipeline to form a second heat energy circulation loop; the energy storage tank is also connected to the ground source side circulation pipeline via a ground source side energy storage branch pipeline;

[0010] The ground source side circulation loop, the heating loop, the first heat energy circulation loop, and the second heat energy circulation loop are all equipped with circulation pumps, and the solar PV / T assembly provides power for each of the circulation pumps; the energy storage tank, the first heat energy circulation loop, and the second heat energy circulation loop are all equipped with temperature sensors;

[0011] A control module is electrically connected to each of the circulation pumps and each of the temperature sensors.

[0012] As a further improvement of the present invention, the geothermal heat exchanger is a double U-shaped buried pipe heat exchanger, and the ground source heat pump unit includes a condenser, an evaporator and a compressor;

[0013] A plurality of double-U-shaped ground heat exchangers are buried below the ground. The ascending sections of the plurality of double-U-shaped ground heat exchangers are connected in parallel and are connected in sequence to the ground source medium inlets of the water collector and the evaporator through a ground source side circulation pipeline. The descending sections of the plurality of double-U-shaped ground heat exchangers are connected in parallel and are connected in sequence to the ground source medium outlets of the water distributor and the evaporator through a ground source side circulation pipeline. A first circulation pump is provided on the ground source side circulation pipeline between the ground source medium inlet and the water collector. The refrigerant outlet of the evaporator is connected in sequence to the refrigerant inlet of the compressor and the condenser through a refrigerant pipeline, and the refrigerant outlet of the condenser is connected to the refrigerant inlet of the evaporator through a refrigerant pipeline.

[0014] The user side medium inlet and the user side medium outlet of the condenser are connected to the user side via user side circulation pipelines respectively, and a second circulation pump is provided on the user side circulation pipeline between the user side medium inlet and the user side.

[0015] As a further improvement of the present invention, a first electric valve is further provided in the ground source side circulation pipeline between the outlet side of the first circulation pump and the ground source medium inlet of the evaporator; and both ends of the ground source side circulation pipeline corresponding to the first electric valve are respectively connected to the interior of the energy storage tank through ground source side energy storage branch pipelines;

[0016] When the first electric valve is in the open state, the ground source medium on the outlet side of the first circulation pump directly enters the evaporator through the ground source side circulation pipeline; when the first electric valve is in the closed state, the ground source medium on the outlet side of the first circulation pump is supplementarily heated by the energy storage tank before entering the evaporator, and the first electric valve is electrically connected to the control module.

[0017] As a further improvement of the present invention, a second electric valve is provided on the outlet side of the air source heat pump unit, and the second electric valve is electrically connected to the control module.

[0018] As a further improvement of the present invention, the solar PV / T assembly includes a photothermal unit and a photovoltaic unit, and the photothermal unit is connected to the second coil heat exchanger in the energy storage tank through a second thermal energy circulation pipeline to form a second thermal energy circulation loop;

[0019] The photovoltaic unit is respectively connected to the DC electric heater and the power storage unit in the energy storage tank. The photovoltaic unit supplements heat for the energy storage tank through the DC electric heater, and the photovoltaic unit stores excess electricity through the power storage unit.

[0020] As a further improvement of the present invention, the power storage unit includes a junction box, an inverter and a power storage device arranged in sequence; the excess electricity generated by the photovoltaic unit passes through the junction box, and is converted from direct current to alternating current by the inverter and then stored in the power storage device; the power storage device supplies power to each circulation pump respectively.

[0021] The present invention discloses a heating and heat storage method for a multi-energy coupling heating system, which is applied to the above-mentioned multi-energy coupling heating system and includes a winter heating mode and a summer heat storage mode;

[0022] In the winter heating mode, the geothermal energy utilization module is used as the basis for supplying heat to the user side, the solar energy utilization module selectively supplements heat for the geothermal energy utilization module, and the air energy utilization module supplements heat when the energy supply is insufficient;

[0023] In the summer heat storage mode, heating to the user side is stopped, and heat is collected by the solar energy utilization module and stored underground through the geothermal heat exchanger of the geothermal energy utilization module to maintain soil thermal balance;

[0024] The electric energy generated by the solar energy utilization module is used to power system equipment and replenish the heat of the energy storage tank.

[0025] As a further improvement of the present invention, the winter heating mode specifically includes:

[0026] The control module starts the geothermal energy utilization module first. The geothermal heat exchanger supplies energy to the geothermal heat pump unit through the ground source side circulation loop. The geothermal heat pump unit supplies heat to the user side through the heating loop.

[0027] When the temperature of the solar PT module and the solar PV / T module reaches a first preset value, heat is transferred to the energy storage tank through the first thermal energy circulation loop and the second thermal energy circulation loop; when the temperature of the energy storage tank reaches a second preset value, the ground source side circulating medium is controlled to be heated by the energy storage tank before entering the ground source heat pump unit;

[0028] When the geothermal energy supply of the geothermal energy utilization module is insufficient, the control module starts the air source heat pump unit to provide supplementary heating to the user side.

[0029] As a further improvement of the present invention, the conditions for starting the air source heat pump unit are: the geothermal energy utilization module is insufficiently supplied with energy, and the outlet temperature of the air energy utilization module is lower than a third preset value;

[0030] When the air source heat pump unit is shut down and its outlet temperature is lower than a fourth preset value, the air source heat pump unit is controlled to start the antifreeze and heating mode.

[0031] As a further improvement of the present invention, the summer heat storage mode specifically includes:

[0032] The control module cuts off the heat supply cycle between the geothermal energy utilization module and the user side, and the solar energy utilization module transmits heat to the energy storage tank through the first and second heat energy circulation loops;

[0033] When the temperature of the energy storage tank reaches the fifth preset value, the ground source side circulation pump is started to transport the heat in the energy storage tank to the geothermal heat exchanger through the ground source side circulation loop to store heat in the underground rock and soil.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] This invention effectively overcomes the technical and economic bottlenecks of single clean energy sources in heating applications by integrating shallow geothermal energy, air energy, and solar energy. Addressing the high initial investment, geological constraints, and imbalanced cooling and heating loads associated with shallow geothermal energy, this invention utilizes solar energy to supplement heating of the ground-source circulating medium, reducing reliance on buried pipes for heat extraction and lowering project costs. Furthermore, by storing heat in the underground rock and soil during summer, it maintains soil thermal balance and prevents system energy efficiency degradation.

[0036] This invention addresses issues such as low-temperature performance degradation and frosting and defrosting energy consumption associated with air-source heat pumps. By using it as a supplemental heat source, it is activated only when geothermal and solar energy are insufficient, reducing operating time in low-temperature environments and, through support from other energy sources, reducing the frequency of frosting and defrosting. To address issues such as the intermittent nature of solar thermal systems and low winter efficiency, this invention utilizes energy storage tanks to store heat, using geothermal and air energy as a stable supplement, while also utilizing solar PV / T modules to generate electricity, thereby increasing energy self-sufficiency and alleviating reliance on auxiliary heat sources.

[0037] In terms of efficiency, the present invention realizes the deep coupling utilization of clean energy. Solar energy dominates the daytime energy supply, geothermal energy provides the basic load, and air energy supplements the demand during low temperature periods, achieving 24-hour coverage. In terms of economy, the initial investment pressure is reduced through government subsidies, the energy free rate exceeds 70%, the operating cost is extremely low, and the peak and valley electricity price optimization can be used to further reduce expenditure. In terms of environmental protection, the annual carbon reduction exceeds 450 tons, zero pollution emissions, and protects the soil ecology.

[0038] The present invention has core advantages such as stability under extreme working conditions, intelligent dynamic optimization, space-intensive design and expansion flexibility. It can ensure continuous heating at low temperatures of -20°C, maximize energy efficiency through intelligent regulation, save space and adapt to future zero-carbon park upgrade needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a structural diagram of a multi-energy coupling heating system disclosed in an embodiment of the present invention.

[0040] In the picture:

[0041] 1. Double U-shaped buried pipe heat exchanger; 2. Ground source heat pump unit; 2-1. Evaporator; 2-2. Condenser; 3. Water distributor; 4. Water collector; 5. First circulation pump; 6. First electric valve; 7. User side; 8. Air source heat pump unit; 9. Second electric valve; 10. Second circulation pump; 11. Solar PV / T module; 12. Solar PT module; 13. Energy storage tank; 14. DC electric heater; 15. Combiner box; 16. Inverter; 17. Power storage device; 18. First temperature sensor; 19. Second temperature sensor; 20. Third temperature sensor; 21. Third circulation pump; 22. Fourth circulation pump; 23. Ground source side circulation pipeline; 24. User side circulation pipeline; 25. First thermal energy circulation pipeline; 26. Second thermal energy circulation pipeline; 27. Ground source side energy storage branch pipeline. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0045] The present invention is described in further detail below with reference to the accompanying drawings:

[0046] like Figure 1 As shown, a multi-energy coupling heating system provided by the present invention includes: a geothermal energy utilization module, an air energy utilization module, a solar energy utilization module, an energy storage tank 13 and a control module, wherein the geothermal energy utilization module includes a geothermal heat exchanger and a ground source heat pump unit 2, and the geothermal heat exchanger is connected to the ground source heat pump unit 2 through a ground source side circulation pipeline 23 to form a ground source side circulation loop; the ground source heat pump unit 2 is also connected to the user side 7 through a user side circulation pipeline 24 to form a heating loop; the air energy utilization module includes an air source heat pump unit 8, and the air source heat pump unit 8 is connected to the heating loop in parallel with the ground source heat pump unit 2 to supplement the heating for the user side 7; the solar energy utilization module includes a solar PT component 12 and a solar PV / T component 11, and the solar PT component 12 is connected to the ground source heat pump unit 2 through a first heat The energy circulation pipeline 25 is connected to the first coil heat exchanger in the energy storage tank 13 to form a first thermal energy circulation loop; the solar PV / T component 11 is connected to the second coil heat exchanger in the energy storage tank 13 through the second thermal energy circulation pipeline 26 to form a second thermal energy circulation loop; the energy storage tank 13 is also connected to the ground source side circulation pipeline 23 through the ground source side energy storage branch pipeline 27; the ground source side circulation loop, the heating loop, the first thermal energy circulation loop, and the second thermal energy circulation loop are all equipped with circulation pumps, and the solar PV / T component 11 provides power for each circulation pump; the energy storage tank 13, the first thermal energy circulation loop, and the second thermal energy circulation loop are all equipped with temperature sensors; the control module is electrically connected to each circulation pump and each temperature sensor, and controls the operation of different modules according to the feedback of each temperature sensor.

[0047] Specifically:

[0048] like Figure 1 As shown in the above embodiment, preferably, the geothermal heat exchanger is a double U-shaped buried pipe heat exchanger 1, and the ground source heat pump unit 2 includes an evaporator 2-1, a condenser 2-2 and a compressor; wherein, multiple double U-shaped buried pipe heat exchangers 1 are buried 200 meters below the ground, and the ascending sections of the multiple double U-shaped buried pipe heat exchangers 1 are connected in parallel and sequentially connected to the water collector 4 and the ground source medium inlet of the evaporator 2-1 through the ground source side circulation pipeline 23; the descending sections of the multiple double U-shaped buried pipe heat exchangers 1 are connected in parallel and sequentially connected to the water distributor 3 and the ground source medium inlet of the evaporator 2-1 through the ground source side circulation pipeline 23. A first circulating pump 5 is provided on the ground-source-side circulation pipeline 23 between the ground-source medium inlet and the water collector 4. The refrigerant outlet of the evaporator 2-1 is connected to the refrigerant inlet of the compressor and the condenser 2-2 in sequence via a refrigerant pipeline. The refrigerant outlet of the condenser 2-2 is connected to the refrigerant inlet of the evaporator 2-1 via a refrigerant pipeline. The user-side medium inlet and user-side medium outlet of the condenser 2-2 are connected to the user-side 7 via a user-side circulation pipeline 24. A second circulating pump 10 is provided on the user-side circulation pipeline 24 between the user-side medium inlet and the user-side 7. In this embodiment, the ground-source heat pump unit 2, the first circulating pump 5, and the second circulating pump 10 are all electrically connected to the control module.

[0049] In the above embodiment, preferably, a plurality of double U-shaped ground heat exchangers 1 are used vertically (-200m), which effectively saves the ground surface area.

[0050] In the above embodiment, preferably, the ground source side circulation pipeline 23 between the outlet side of the first circulation pump 5 and the ground source medium inlet of the evaporator 2-1 is also provided with a first electric valve 6; the two ends of the ground source side circulation pipeline 23 corresponding to the first electric valve 6 are respectively connected to the inside of the energy storage tank 13 through the ground source side energy storage branch pipeline 27; in actual use, when the first electric valve 6 is in the open state, the ground source medium on the outlet side of the first circulation pump 5 directly enters the evaporator 2-1 through the ground source side circulation pipeline 23; when the first electric valve 6 is in the closed state, the ground source medium on the outlet side of the first circulation pump 5 enters the energy storage tank 13 after passing through the ground source side energy storage branch pipeline 27 for supplementary heating, and then enters the evaporator 2-1, and the first electric valve 6 is electrically connected to the control module.

[0051] In the above embodiment, preferably, the double-U-shaped underground heat exchanger 1 has a double-U-shaped structure, the pipe material is a De32 PE pipe, and the well depth is 200m.

[0052] In the above embodiment, preferably, a second electric valve 9 is provided on the outlet side of the air source heat pump unit 8 , and the air source heat pump unit 8 , the second electric valve 9 and the control module are electrically connected.

[0053] In the above embodiment, preferably, the solar PV / T assembly 11 includes a photothermal unit and a photovoltaic unit. The photothermal unit is connected to the second coil heat exchanger in the energy storage tank 13 through the second thermal energy circulation pipeline 26 to form a second thermal energy circulation loop; the photovoltaic unit is respectively connected to the DC electric heater 14 and the power storage unit in the energy storage tank 13. The photovoltaic unit supplements heat for the energy storage tank 13 through the DC electric heater 14, and the photovoltaic unit stores excess electricity through the power storage unit.

[0054] In the above embodiment, preferably, the solar PV / T assembly 11 and the solar PT assembly 12 are roof-integrated to achieve the triple functions of "power generation + heat collection + sun shading".

[0055] In the above embodiment, preferably, the first heat energy circulation pipeline 25 is provided with a fourth circulation pump 22 , the second heat energy circulation pipeline 26 is provided with a third circulation pump 21 , and both the third circulation pump 21 and the fourth circulation pump 22 are electrically connected to the control module.

[0056] In the above embodiment, preferably, the power storage unit includes a junction box 15, an inverter 16 and a power storage device 17 arranged in sequence; the excess power generated by the photovoltaic unit passes through the junction box 15, and is converted from direct current to alternating current by the inverter 16 and then stored in the power storage device 17; the power storage device 17 supplies power to the first circulation pump 5, the second circulation pump 10, the third circulation pump 21 and the fourth circulation pump 22 respectively.

[0057] In the above embodiment, preferably, the geothermal energy utilization module is activated first, and when the heating temperature cannot meet the demand, the air energy utilization module is activated.

[0058] In the above embodiment, preferably, valve control is performed based on load forecasting, and the electric valve automatically switches the heat source according to the water temperature signal; cloud-based energy scheduling matches meteorological data, electricity price signals, and user loads in real time to maximize the overall energy efficiency of the system.

[0059] The heating and heat storage method of the multi-energy coupling heating system provided by the present invention is applied to the above-mentioned multi-energy coupling heating system, and is characterized in that it includes a winter heating mode and a summer heat storage mode;

[0060] In winter heating mode, the geothermal energy utilization module is used as the basis to supply heat to the user side 7, the solar energy utilization module selectively supplements heat to the geothermal energy utilization module, and the air energy utilization module supplements heat when the energy supply is insufficient;

[0061] In the summer heat storage mode, heating to the user side 7 is stopped, and heat is collected by the solar energy utilization module and stored underground through the geothermal heat exchanger of the geothermal energy utilization module to maintain the thermal balance of the soil;

[0062] The electricity generated by the solar energy utilization module is used to power system equipment and replenish the heat of the energy storage tank 13.

[0063] In the above embodiment, preferably, the winter heating mode specifically includes:

[0064] The control module starts the geothermal energy utilization module first, and the geothermal heat exchanger supplies energy to the geothermal heat pump unit 2 through the ground source side circulation loop, and the geothermal heat pump unit 2 supplies heat to the user side 7 through the heating loop;

[0065] When the temperature of the solar PT component 12 and the solar PV / T component 11 reaches a first preset value, heat is transferred to the energy storage tank 13 through the first heat energy circulation loop and the second heat energy circulation loop; when the temperature of the energy storage tank 13 reaches a second preset value, the ground source side circulating medium is controlled to be heated by the energy storage tank 13 before entering the ground source heat pump unit 2;

[0066] When the geothermal energy supply of the geothermal energy utilization module is insufficient, the control module starts the air source heat pump unit 8 to provide supplementary heating to the user side 7.

[0067] In the above embodiment, preferably, the conditions for starting the air source heat pump unit 8 are: the geothermal energy utilization module is insufficiently supplied with energy, and the outlet temperature of the air energy utilization module is lower than the third preset value;

[0068] When the air source heat pump unit 8 is shut down and its outlet temperature is lower than the fourth preset value, the air source heat pump unit 8 is controlled to start the antifreeze and heating mode.

[0069] In the above embodiment, preferably, the summer heat storage mode specifically includes:

[0070] The control module cuts off the heat supply cycle between the geothermal energy utilization module and the user side 7, and the solar energy utilization module transfers heat to the energy storage tank 13 through the first heat energy circulation loop and the second heat energy circulation loop;

[0071] When the temperature of the energy storage tank 13 reaches the fifth preset value, the first circulation pump 5 on the ground source side is started, so that the heat in the energy storage tank 13 is transported to the geothermal heat exchanger through the ground source side circulation loop to store heat in the underground rock and soil.

[0072] Example 1:

[0073] In winter operation mode:

[0074] The first electric valve 6 automatically opens, and the circulating medium in the buried pipe directly enters the evaporator 2-1 of the ground-source heat pump unit 2, serving as a heat source. When the temperature of the first temperature sensor 18 and the second temperature sensor 19 reaches 30°C (adjustable), the control module turns on the third circulating pump 21 and the fourth circulating pump 22, respectively. At this time, the solar PV / T module 11 and the solar PT module 12 absorb solar radiation heat energy and heat the water in the energy storage tank 13 through the intermediate medium.

[0075] When the water in the energy storage tank 13 is heated to 15°C as measured by the third temperature sensor 20, the first electric valve 6 automatically closes and adjusts (the opening of the first electric valve 6 changes with the temperature of the circulating medium entering the evaporator 2-1 of the ground-source heat pump unit 2, and the temperature of the circulating water entering the evaporator 2-1 is always kept below 25°C). At this time, the circulating medium in the buried pipe driven by the first circulation pump 5 enters the energy storage tank 13 and is heated, and then enters the evaporator 2-1 of the ground-source heat pump unit 2, completing the ground-source side heat extraction cycle of solar-assisted heating.

[0076] The solar PV / T assembly 11 generates DC power while receiving solar radiation energy to generate heat. Part of the generated DC power is used to heat the circulating medium in the energy storage tank 13 through the DC heater 14 to supplement the heat of the energy storage tank 13. The DC heater 14 (power 7.5kW) operates for 2 to 3 hours in winter (optional). The other part passes through the junction box 15 and then the inverter 16 to convert the DC power into AC power and store it in the power storage device 17. The power stored in the power storage device 17 is used to ensure the power required by the third circulation pump 21 and the fourth circulation pump 22. The remaining power can be used for the first circulation pump 5 in the system. When the power is insufficient, it can also be connected to the power grid for free conversion.

[0077] The system prioritizes putting the ground source heat pump unit 2 into operation. When the heat cannot meet the requirements, the air source heat pump unit 8 is put into operation. When the outlet water temperature of the air source heat pump unit 8 is lower than 50°C (settable), the air source heat pump unit 8 is started. If the heat meets the requirements, the air source heat pump unit 8 is shut down first, and the second electric valve 9 is closed at the same time. When the air source heat pump unit 8 is in the unloaded shutdown state and it is monitored that the outlet water temperature of the air source heat pump unit 8 is lower than 7°C, the air source heat pump unit 8 automatically turns on the antifreeze mode and the second electric valve 9 automatically opens; at this time, the air source heat pump unit 8 starts to supplement the heat to the heating system to ensure that the indoor temperature on the user side 7 meets the design requirements.

[0078] In summer operation mode:

[0079] When the first electric valve 6 is closed, the solar PV / T module 11 and the solar PT module 12 absorb solar radiation energy and generate heat energy, causing the module temperature to rise. When the temperature measured by the first temperature sensor 18 and the second temperature sensor 19 reaches 40°C, the third circulation pump 21 and the fourth circulation pump 22 are turned on to use the heat energy generated by the solar radiation energy to heat the water in the energy storage tank 13;

[0080] When the temperature of the third temperature sensor 20 reaches 30°C (optional), the first circulation pump 5 is started to transport the heat energy of the energy storage tank 13 to the double U-shaped buried pipe heat exchanger 1 through the circulating medium, and supplement heat to the underground rock and soil to form an underground "heat storage"; for every 1°C increase in the operating temperature of the solar PV / T component 11, the power generation efficiency will decrease by 0.3% to 0.5%, and the maximum temperature shall not exceed 40°C. That is, no matter which of the first temperature sensor 18 or the third temperature sensor 20 reaches the set temperature first, the first circulation pump 5 must be started to transport the heat to the buried pipe heat exchange system for heat storage, which is a double protection for the power generation efficiency of the solar PV / T component 11.

[0081] The solar PV / T assembly 11 generates DC power at the same time as generating heat energy. Part of the generated DC power is used to heat the circulating medium in the energy storage tank 13 through the DC heater 14 to supplement the heat of the energy storage tank 13. The DC heater 14 (power 7.5kW) operates for 3 to 4 hours in summer (optional). The other part of the DC power passes through the junction box 15, and then is converted into AC power by the inverter 16 and stored in the power storage device 17. The power stored in the power storage device 17 is used to supply the power required by the first circulating pump 5, the second circulating pump 10 and the third circulating pump 21, thereby reducing the system's consumption of municipal power grid energy.

[0082] Advantages of the present invention:

[0083] This invention effectively overcomes the technical and economic bottlenecks of single clean energy sources in heating applications by integrating shallow geothermal energy, air energy, and solar energy. Addressing the high initial investment, geological constraints, and imbalanced cooling and heating loads associated with shallow geothermal energy, this invention utilizes solar energy to supplement heating of the ground-source circulating medium, reducing reliance on buried pipes for heat extraction and lowering project costs. Furthermore, by storing heat in the underground rock and soil during summer, it maintains soil thermal balance and prevents system energy efficiency degradation.

[0084] The present invention solves problems such as the attenuation of low-temperature performance and the energy consumption of frosting and defrosting in air-source heat pumps. It uses it as a supplementary heat source, starting only when geothermal and solar energy are insufficient, reducing its operating time in low-temperature environments and reducing the frequency of frosting and defrosting through the support of other energy sources. To address the intermittent nature of solar thermal systems and their low winter efficiency, the present invention utilizes an energy storage tank 13 to store heat, using geothermal and air energy as a stable supplement, while also utilizing solar PV / T modules 11 to generate electricity, thereby increasing energy self-sufficiency and alleviating reliance on auxiliary heat sources.

[0085] As shown in Table 1, the present invention achieves deep coupling utilization of clean energy in terms of benefits. Solar energy dominates daytime energy supply, geothermal energy provides basic load, and air energy supplements demand during low-temperature periods, achieving 24-hour coverage. In terms of economy, government subsidies reduce initial investment pressure, the energy free rate exceeds 70%, and the operating cost is extremely low. Peak and valley electricity price optimization can be used to further reduce expenditure. In terms of environmental protection, the annual carbon reduction exceeds 450 tons (based on a heating area of ​​10,000 m2), with zero pollution emissions, no SO2, and no NO x and dust emissions, solve the pain points of haze, protect soil ecology, maintain soil thermal balance, and avoid soil cold accumulation and degradation caused by traditional ground source systems.

[0086] Table 1. Comparison of the advantages of multi-energy coupling heating system and traditional coal-fired boiler

[0087]

[0088] The present invention has core advantages such as stability under extreme working conditions, intelligent dynamic optimization, space-intensive design and expansion flexibility. It can ensure continuous heating at low temperatures of -20°C, maximize energy efficiency through intelligent regulation, save space and adapt to future zero-carbon park upgrade needs.

[0089] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A multi-energy coupling heating system, characterized in that: include: The geothermal energy utilization module includes a geothermal heat exchanger and a geothermal heat pump unit. The geothermal heat exchanger is connected to the geothermal heat pump unit through a geothermal side circulation pipeline to form a geothermal side circulation loop; the geothermal heat pump unit is also connected to the user side through a user side circulation pipeline to form a heating loop; An air energy utilization module, comprising an air source heat pump unit, wherein the air source heat pump unit and the ground source heat pump unit are connected in parallel to the heating circuit to provide supplementary heating for the user side; A solar energy utilization module includes a solar PT component and a solar PV / T component. The solar PT component is connected to a first coil heat exchanger in an energy storage tank via a first heat energy circulation pipeline to form a first heat energy circulation loop; the solar PV / T component is connected to a second coil heat exchanger in the energy storage tank via a second heat energy circulation pipeline to form a second heat energy circulation loop; the energy storage tank is also connected to the ground source side circulation pipeline via a ground source side energy storage branch pipeline; The ground source side circulation loop, the heating loop, the first heat energy circulation loop, and the second heat energy circulation loop are all equipped with circulation pumps, and the solar PV / T assembly provides power for each of the circulation pumps; the energy storage tank, the first heat energy circulation loop, and the second heat energy circulation loop are all equipped with temperature sensors; A control module is electrically connected to each of the circulation pumps and each of the temperature sensors.

2. The multi-energy coupling heating system according to claim 1, characterized in that: The geothermal heat exchanger is a double U-shaped buried pipe heat exchanger, and the ground source heat pump unit includes a condenser, an evaporator and a compressor; A plurality of double-U-shaped ground heat exchangers are buried below the ground. The ascending sections of the plurality of double-U-shaped ground heat exchangers are connected in parallel and are connected in sequence to the ground source medium inlets of the water collector and the evaporator through a ground source side circulation pipeline. The descending sections of the plurality of double-U-shaped ground heat exchangers are connected in parallel and are connected in sequence to the ground source medium outlets of the water distributor and the evaporator through a ground source side circulation pipeline. A first circulation pump is provided on the ground source side circulation pipeline between the ground source medium inlet and the water collector. The refrigerant outlet of the evaporator is connected in sequence to the refrigerant inlet of the compressor and the condenser through a refrigerant pipeline, and the refrigerant outlet of the condenser is connected to the refrigerant inlet of the evaporator through a refrigerant pipeline. The user side medium inlet and the user side medium outlet of the condenser are connected to the user side via user side circulation pipelines respectively, and a second circulation pump is provided on the user side circulation pipeline between the user side medium inlet and the user side.

3. The multi-energy coupling heating system according to claim 2, characterized in that: A first electric valve is further provided in the ground source side circulation pipeline between the outlet side of the first circulation pump and the ground source medium inlet of the evaporator; the two ends of the ground source side circulation pipeline corresponding to the first electric valve are respectively connected to the interior of the energy storage tank through ground source side energy storage branch pipelines; When the first electric valve is in an open state, the ground source medium at the outlet side of the first circulation pump directly enters the evaporator through the ground source side circulation pipeline; When the first electric valve is in a closed state, the ground source medium at the outlet side of the first circulation pump is supplementarily heated by the energy storage tank before entering the evaporator, and the first electric valve is electrically connected to the control module.

4. The multi-energy coupling heating system according to claim 1, characterized in that: A second electric valve is provided at the outlet side of the air source heat pump unit, and the second electric valve is electrically connected to the control module.

5. The multi-energy coupling heating system according to claim 1, characterized in that: The solar PV / T assembly includes a photothermal unit and a photovoltaic unit, and the photothermal unit is connected to the second coil heat exchanger in the energy storage tank through a second heat energy circulation pipeline to form a second heat energy circulation loop; The photovoltaic unit is respectively connected to the DC electric heater and the power storage unit in the energy storage tank. The photovoltaic unit supplements heat for the energy storage tank through the DC electric heater, and the photovoltaic unit stores excess electricity through the power storage unit.

6. The multi-energy coupling heating system according to claim 5, characterized in that: The power storage unit includes a junction box, an inverter and a power storage device arranged in sequence; the excess electricity generated by the photovoltaic unit passes through the junction box, and is converted from direct current to alternating current by the inverter and then stored in the power storage device; the power storage device supplies power to each circulating pump respectively.

7. A heating and heat storage method for a multi-energy coupling heating system, applied to the multi-energy coupling heating system according to any one of claims 1 to 6, characterized in that: Including winter heating mode and summer heat storage mode; In the winter heating mode, the geothermal energy utilization module is used as the basis for supplying heat to the user side, the solar energy utilization module selectively supplements heat for the geothermal energy utilization module, and the air energy utilization module supplements heat when the energy supply is insufficient; In the summer heat storage mode, heating to the user side is stopped, and heat is collected by the solar energy utilization module and stored underground through the geothermal heat exchanger of the geothermal energy utilization module to maintain soil thermal balance; The electric energy generated by the solar energy utilization module is used to power system equipment and replenish the heat of the energy storage tank.

8. The heating and heat storage method according to claim 7, characterized in that: The winter heating mode specifically includes: The control module starts the geothermal energy utilization module first. The geothermal heat exchanger supplies energy to the geothermal heat pump unit through the ground source side circulation loop. The geothermal heat pump unit supplies heat to the user side through the heating loop. When the temperature of the solar PT module and the solar PV / T module reaches a first preset value, heat is transferred to the energy storage tank through the first thermal energy circulation loop and the second thermal energy circulation loop; when the temperature of the energy storage tank reaches a second preset value, the ground source side circulating medium is controlled to be heated by the energy storage tank before entering the ground source heat pump unit; When the geothermal energy supply of the geothermal energy utilization module is insufficient, the control module starts the air source heat pump unit to provide supplementary heating to the user side.

9. The heating and heat storage method according to claim 8, characterized in that: The conditions for starting the air source heat pump unit are: the geothermal energy utilization module is insufficiently supplied with energy, and the outlet temperature of the air energy utilization module is lower than a third preset value; When the air source heat pump unit is shut down and its outlet temperature is lower than a fourth preset value, the air source heat pump unit is controlled to start the antifreeze and heating mode.

10. The heating and heat storage method according to claim 7, characterized in that: The summer heat storage mode specifically includes: The control module cuts off the heat supply cycle between the geothermal energy utilization module and the user side, and the solar energy utilization module transmits heat to the energy storage tank through the first and second heat energy circulation loops; When the temperature of the energy storage tank reaches the fifth preset value, the ground source side circulation pump is started to transport the heat in the energy storage tank to the geothermal heat exchanger through the ground source side circulation loop to store heat in the underground rock and soil.

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