Thermovoltaic power generation system based on large temperature difference across seasons and its operation method

Abstract

The present invention relates to the technical field of energy storage and power generation, and discloses a thermovoltaic power generation system based on a large temperature difference across seasons and an operation method thereof. The thermovoltaic power generation system with a large temperature difference across seasons includes a thermovoltaic power generation unit, a heating unit and a cooling unit. The heating unit is connected to the heat absorption side of the thermovoltaic power generation unit for heat exchange; the cooling unit includes a total cooling pipeline, an air cooling unit, an underground cooling unit and a reversing valve group, and the total cooling pipeline is connected to the heat release side of the thermovoltaic power generation unit for heat exchange; the underground cooling unit includes an underground cold storage structure and a heat exchange component. When the outdoor temperature is lower than the set value, the underground cold storage structure is suitable for exchanging heat with the external environment through the heat exchange component to store cold energy. The present invention introduces the natural cold energy across seasons in winter into the ground through the heat exchange component as a natural cold source, and stores the cold energy through the underground cold storage structure as a cold source in summer, thereby increasing the temperature difference between the cold and hot sources of the thermovoltaic power generation unit and improving the power generation efficiency of the thermovoltaic power generation unit.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage power generation, and in particular to a thermovoltaic power generation system based on large temperature differences across seasons and an operation method thereof. Background Art

[0002] At present, the temperature difference of existing thermovoltaic power generation systems mostly comes from artificial cold and heat sources. The temperature difference between cold and heat sources is generally small, and the system energy efficiency is low. A small number of thermovoltaic power generation uses geothermal water as the heat source and river water as the cold source, which is subject to great geographical restrictions. Some researchers use photovoltaic waste heat as the heat source and the natural environment as the cold source, which has high costs and insufficient temperature difference, resulting in low power generation efficiency.

[0003] Thermovoltaic power generation systems mainly rely on temperature differences to generate electricity. The low power generation efficiency is one of the main reasons why it is difficult to promote and apply. Under normal conditions, it is difficult to ensure a large temperature difference between hot and cold, resulting in low power generation efficiency. Summary of the invention

[0004] In view of this, the present invention provides a thermovoltaic power generation system based on large temperature differences across seasons and an operation method thereof to solve the problem of low power generation efficiency.

[0005] In the first aspect, the present invention provides a thermovoltaic power generation system with a large temperature difference across seasons, including a thermovoltaic power generation unit, a heating unit and a cooling unit. The thermovoltaic power generation unit includes a heat absorption side and a heat release side; the heating unit is connected to the heat absorption side of the thermovoltaic power generation unit for heat exchange; the cooling unit includes a total cooling pipeline, an air cooling unit, an underground cooling unit and a reversing valve group, and the total cooling pipeline is connected to the heat release side of the thermovoltaic power generation unit for heat exchange; the underground cooling unit includes an underground cold storage structure and a heat exchange component, and when the outdoor temperature is lower than the set value, the underground cold storage structure is suitable for exchanging heat with the external environment through the heat exchange component to store cold; the reversing valve group selectively connects the air cooling unit or the underground cooling unit to the total cooling pipeline; when the outdoor temperature is lower than the set value, the air cooling unit is connected to the total cooling pipeline; when the outdoor temperature is higher than the set value, the underground cooling unit is connected to the total cooling pipeline.

[0006] Beneficial effects: The present invention introduces the natural cold energy across the winter seasons into the ground through the heat exchange component as a natural cold source, and stores the cold energy through the underground cold storage structure as a cold source in summer, thereby increasing the temperature difference between the cold and hot sources of the thermovoltaic power generation unit, improving the power generation efficiency of the thermovoltaic power generation unit, and having a low cold storage cost and high safety. The present invention can convert low-grade cold energy into high-grade electrical energy, thereby improving energy utilization; and regardless of winter or summer, the cold and hot sources of the thermovoltaic power generation unit are in large temperature difference operation, which can ensure efficient power generation of the power generation system throughout the year; the cost of passive cold storage is low, and the economic efficiency of the thermovoltaic power generation system is high, which has the value of large-scale promotion.

[0007] In an optional embodiment, the heat exchange assembly includes a plurality of vertically arranged unidirectional gravity heat pipes, the lower ends of the unidirectional gravity heat pipes extend into the interior of the underground cold storage structure, and the upper ends of the unidirectional gravity heat pipes extend above the ground. The unidirectional gravity heat pipes are used to circulate low-boiling-point phase-change working fluids.

[0008] In an optional embodiment, the heat exchange assembly further includes a plurality of heat exchange fins, and the heat exchange fins are arranged at the top end of the unidirectional gravity heat pipe and / or the bottom end of the unidirectional gravity heat pipe.

[0009] In an optional embodiment, the underground cold storage structure includes an underground energy storage water body.

[0010] In an optional embodiment, the underground cooling unit further includes an underground cooling branch, which passes through the underground cold storage structure; the reversing valve group includes a first three-way valve and a second three-way valve; the upstream end of the underground cooling branch is connected to the main cooling pipeline through the first three-way valve, and the downstream end of the underground cooling branch is connected to the main cooling pipeline through the second three-way valve;

[0011] And / or, the air cooling unit includes an air cooling branch and an air cooler connected to the air cooling branch; the reversing valve group includes a third three-way valve and a fourth three-way valve; the upstream end of the air cooling branch is connected to the main cooling pipeline through the third three-way valve, and the downstream end of the air cooling branch is connected to the main cooling pipeline through the fourth three-way valve.

[0012] In an optional embodiment, the thermovoltaic power generation unit includes a thermovoltaic power generation plate, which includes a positive plate and a negative plate, wherein the side where the positive plate is located is a heat release side, and the side where the negative plate is located is a heat absorption side.

[0013] In an optional embodiment, a plurality of thermovoltaic power generation panels are provided, and the plurality of thermovoltaic power generation panels are distributed in parallel in an umbrella shape.

[0014] In an optional embodiment, the thermovoltaic power generation unit further includes a heat distributor, which is used to distribute cold or heat to each thermovoltaic power generation panel.

[0015] In an optional embodiment, the thermovoltaic power generation unit further includes a power collector, which is used to collect the electricity generated by the thermovoltaic power generation panel, and the power collector supplies electricity to the power user through a power line.

[0016] In a second aspect, the present invention also provides an operation method of a thermovoltaic power generation system with a large temperature difference across seasons, comprising the following steps:

[0017] When the outdoor temperature is lower than the set value:

[0018] The air cooling unit is connected to the main cooling pipeline to use the cold energy in the environment to cool down the heat release side of the thermovoltaic power generation unit;

[0019] The heating unit is used to heat the heat absorbing side of the thermovoltaic power generation unit, and the thermovoltaic power generation unit generates electricity by using the temperature difference to supply electricity to the power user;

[0020] Use heat exchange components to store the natural cold from the outside in the underground cold storage structure;

[0021] When the outdoor temperature is higher than the set value:

[0022] The underground cooling unit is connected to the main cooling pipeline, and the cold energy stored in the underground cold storage structure is used to cool down the heat release side of the thermovoltaic power generation unit;

[0023] The heating unit is used to heat the heat absorbing side of the thermovoltaic power generation unit, and the thermovoltaic power generation unit generates electricity using the temperature difference and supplies electricity to the power users.

[0024] Beneficial effect: Because this operation method is aimed at the thermovoltaic power generation system with large temperature difference across seasons described in the above technical solution, it has the same effect as the thermovoltaic power generation system with large temperature difference across seasons, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 This is a schematic structural diagram of a thermovoltaic power generation system with a large temperature difference across seasons according to an embodiment of the present invention;

[0027] Figure 2 for Figure 1 A schematic diagram of the structure of a thermovoltaic power generation unit in a thermovoltaic power generation system with a large temperature difference across seasons is shown;

[0028] Figure 3 The figure is a flow chart of the operation method of a thermovoltaic power generation system with large temperature differences across seasons.

[0029] Description of reference numerals:

[0030] 10. Thermovoltaic power generation unit; 11. Thermovoltaic power generation panel; 12. Heat distributor; 13. Power collector; 21. Solar collector; 22. Heat exchange pipeline; 31. Main cooling pipeline; 32. Air cooling unit; 321. Air cooling branch; 322. Air cooler; 33. Underground cooling unit; 331. Underground cold storage structure; 332. Heat exchange component; 3321. One-way gravity heat pipe; 3322. Heat exchange fin; 333. Underground cooling branch; 34. Reversing valve group; 341. First three-way valve; 342. Second three-way valve; 343. Third three-way valve; 344. Fourth three-way valve; 40. Power user. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] Combine the following Figures 1 to 3 , describing an embodiment of the present invention.

[0033] According to an embodiment of the present invention, on the one hand, a thermovoltaic power generation system with a large temperature difference across seasons is provided, comprising a thermovoltaic power generation unit 10, a heating unit and a cooling unit. The thermovoltaic power generation unit 10 comprises a heat absorption side and a heat release side; the heating unit is connected to the heat absorption side of the thermovoltaic power generation unit 10 by heat exchange; the cooling unit comprises a total cooling pipeline 31, an air cooling unit 32, an underground cooling unit 33 and a reversing valve group 34, and the total cooling pipeline 31 is connected to the heat release side of the thermovoltaic power generation unit 10 by heat exchange; the underground cooling unit 33 comprises an underground cold storage structure 331 and a heat exchange component 332, and when the outdoor temperature is lower than the set value, the underground cold storage structure 331 is suitable for heat exchange with the external environment through the heat exchange component 332 to store cold; the reversing valve group 34 selectively connects the air cooling unit 32 or the underground cooling unit 33 to the total cooling pipeline 31; when the outdoor temperature is lower than the set value, the air cooling unit 32 is connected to the total cooling pipeline 31; when the outdoor temperature is higher than the set value, the underground cooling unit 33 is connected to the total cooling pipeline 31.

[0034] The thermovoltaic power generation system with large temperature differences across seasons provided in the embodiment of the present invention can generate electricity by utilizing the temperature difference by setting a thermovoltaic power generation unit 10 , thereby supplying electricity to the power user 40 .

[0035] Since the heat absorbing side of the thermovoltaic power generation unit 10 is connected to the heating unit for heat exchange, the temperature of the heat absorbing side of the thermovoltaic power generation unit 10 can be increased under the heating action of the heating unit. Since the heat releasing side of the thermovoltaic power generation unit 10 is connected to the cooling unit for heat exchange, the temperature of the heat releasing side of the thermovoltaic power generation unit 10 can be reduced under the cooling action of the cooling unit. Therefore, under the joint action of the heating unit and the cooling unit, the temperature difference between the heat absorbing side and the heat releasing side of the thermovoltaic power generation unit 10 can be increased, thereby improving the power generation efficiency.

[0036] The cross-seasonal large temperature difference thermovoltaic power generation system provided by the embodiment of the present invention has a cooling unit including an air cooling unit 32 and an underground cooling unit 33, that is, the heat release side of the thermovoltaic power generation unit 10 can be cooled by either the air cooling unit 32 or the underground cooling unit 33, and one of them can be selected as the cold source through the reversing valve group 34. In general, in winter, the ambient temperature is low. At this time, the air cooling unit 32 and the main cooling pipeline 31 are connected for heat exchange, so that the natural cold in the environment can be used to cool the heat release side of the thermovoltaic power generation unit 10, increase the temperature difference between the heat absorption side and the heat release side of the thermovoltaic power generation unit 10, and improve the power generation efficiency. At the same time, the heat exchange component 332 can be used to store the natural cold in the winter environment in the underground cold storage structure 331. In summer, the underground cooling unit 33 and the main cooling pipeline 31 are connected for heat exchange. Therefore, the cross-seasonal natural cold stored in the underground cold storage structure 331 can be used to cool the heat release side of the thermovoltaic power generation unit 10, thereby increasing the temperature difference between the heat absorption side and the heat release side of the thermovoltaic power generation unit 10 and improving the power generation efficiency.

[0037] The embodiment of the present invention introduces the natural cold energy across the winter seasons into the ground through the heat exchange component 332 as a natural cold source, and stores the cold energy through the underground cold storage structure 331 as a cold source in summer, thereby increasing the temperature difference between the cold and hot sources of the thermovoltaic power generation unit 10, improving the power generation efficiency of the thermovoltaic power generation unit 10, and having low cold storage costs and high safety.

[0038] The cross-season large temperature difference thermovoltaic power generation system provided by the present invention can convert low-grade cold energy into high-grade electrical energy, thereby improving energy utilization; and regardless of winter or summer, the cold and heat sources of the thermovoltaic power generation unit 10 are in large temperature difference operation, which can ensure efficient power generation of the power generation system throughout the year; the cost of passive cold storage is low, the thermovoltaic power generation system is highly economical, and has large-scale promotion value.

[0039] Specifically, since the temperatures in winter and summer are different in different regions, a temperature set value can be set. When the temperature is lower than the set value, the winter operating condition can be adopted, and the air cooling unit 32 is used as the cold source; when the temperature is higher than the set value, the summer operating condition can be adopted, and the underground cooling unit 33 is used as the cold source.

[0040] In some embodiments, the heat exchange component 332 includes a plurality of vertically arranged unidirectional gravity heat pipes 3321, the lower ends of the unidirectional gravity heat pipes 3321 extend into the interior of the underground cold storage structure 331, and the upper ends of the unidirectional gravity heat pipes 3321 extend above the ground. The unidirectional gravity heat pipes 3321 are used to circulate low-boiling-point phase-change working fluids.

[0041] A one-way gravity heat pipe 3321 is used, one part of which extends into the ground and one part of which is exposed on the ground. In this way, the cold energy in the environment can be stored underground by using the one-way gravity heat pipe 3321. Specifically, a low-boiling point phase change medium circulates in the one-way gravity heat pipe 3321, which is in liquid state underground. After absorbing the heat underground, the low-boiling point phase change medium is heated and evaporated into a gaseous state, and rises to the ground along the one-way gravity heat pipe 3321. Since the ambient temperature in winter is relatively low, the gaseous low-boiling point phase change medium is condensed into a liquid state, and flows back to the ground along the one-way gravity heat pipe 3321. This cycle is repeated, and the cold energy in the winter ambient temperature is continuously stored underground, and is taken out in summer, realizing the storage of cold energy across seasons.

[0042] In some embodiments, the heat exchange assembly 332 further includes a plurality of heat exchange fins 3322 , and the heat exchange fins 3322 are disposed at the top end of the unidirectional gravity heat pipe 3321 and / or the bottom end of the unidirectional gravity heat pipe 3321 .

[0043] By providing heat exchange fins 3322 on the unidirectional gravity heat pipe 3321, the heat exchange effect can be enhanced. Figure 1 As shown, in this embodiment, a plurality of heat exchange fins 3322 are provided at the top and bottom of the unidirectional gravity heat pipe 3321, so as to enhance the heat exchange effect above and below the ground.

[0044] In some embodiments, the underground cold storage structure 331 includes an underground energy storage water body.

[0045] By utilizing underground energy storage water bodies, we can directly utilize natural energy storage resources, which is highly economical.

[0046] In some embodiments, the underground energy storage water body includes cavitation and fissure water.

[0047] The underground energy storage water body uses hollow fissure water to ensure that the stored cold is not lost.

[0048] In some embodiments, the underground cooling unit 33 further includes an underground cooling branch 333, and the underground cooling branch 333 passes through the underground cold storage structure 331; the reversing valve group 34 includes a first three-way valve 341 and a second three-way valve 342; the upstream end of the underground cooling branch 333 is connected to the main cooling pipeline 31 through the first three-way valve 341, and the downstream end of the underground cooling branch 333 is connected to the main cooling pipeline 31 through the second three-way valve 342;

[0049] And / or, the air cooling unit 32 includes an air cooling branch 321 and an air cooler 322 connected to the air cooling branch 321; the reversing valve group 34 includes a third three-way valve 343 and a fourth three-way valve 344; the upstream end of the air cooling branch 321 is connected to the main cooling pipeline 31 through the third three-way valve 343, and the downstream end of the air cooling branch 321 is connected to the main cooling pipeline 31 through the fourth three-way valve 344.

[0050] Specifically, in summer, the first three-way valve 341 and the second three-way valve 342 are controlled to switch directions, and the underground cooling branch 333 and the main cooling pipeline 31 are connected to form a cooling circuit. At this time, the air cooling branch 321 is disconnected from the main cooling pipeline 31, and the underground cooling unit 33 serves as a cooling source.

[0051] In winter, the first three-way valve 341, the third three-way valve 343 and the fourth three-way valve 344 are controlled to switch directions, and the air cooling branch 321 is connected to the main cooling pipeline 31 to form a cooling circuit. At this time, the underground cooling branch 333 is disconnected from the main cooling pipeline 31. The air cooling unit 32 serves as a cold source.

[0052] In some embodiments, the thermovoltaic power generation unit 10 includes a thermovoltaic power generation plate 11, which includes a positive plate and a negative plate. The side where the positive plate is located is a heat release side, and the side where the negative plate is located is a heat absorption side.

[0053] The thermovoltaic power generation unit 10 generates electricity using the temperature difference between the positive electrode side and the negative electrode side of the thermovoltaic power generation panel 11 .

[0054] In some embodiments, a plurality of thermovoltaic power generation panels 11 are provided, and the plurality of thermovoltaic power generation panels 11 are distributed in parallel in an umbrella shape.

[0055] By providing a plurality of thermovoltaic power generation panels 11, the power generation of the thermovoltaic power generation panels 11 can be increased. The plurality of thermovoltaic power generation panels 11 are arranged in parallel in an umbrella shape, such as Figure 2 As shown, such an arrangement is beneficial to saving the floor space of the thermovoltaic power generation unit 10 and facilitates large-scale integration of the thermovoltaic power generation panels 11.

[0056] In some embodiments, the thermovoltaic power generation unit 10 further includes a heat distributor 12 , and the heat distributor 12 is used to distribute cold or heat to each thermovoltaic power generation panel 11 .

[0057] In the thermovoltaic power generation unit 10, by setting a heat distributor 12, cold or heat can be distributed to each thermovoltaic power generation panel 11, thereby ensuring that the positive side and the negative side of each thermovoltaic power generation panel 11 can achieve a large temperature difference, thereby improving the power generation efficiency of the thermovoltaic power generation panel 11.

[0058] In some embodiments, the thermovoltaic power generation unit 10 further includes a power collector 13 , which is used to collect electricity generated by the thermovoltaic power generation panel 11 , and the power collector 13 supplies electricity to the power user 40 through a power line.

[0059] In the thermovoltaic power generation unit 10 , by providing the power collector 13 , the power generated by the thermovoltaic power generation panel 11 can be collected, so as to facilitate supplying power to the power user 40 through the power line.

[0060] In some embodiments, the heating unit includes a solar collector 21 and a heat exchange pipeline 22 connected to a medium inlet and a medium outlet of the solar collector 21 , and the heat exchange pipeline 22 is connected to the thermovoltaic power generation unit 10 for heat exchange.

[0061] Specifically, the solar collector 21 can collect solar heat and heat the heat-absorbing side of the thermovoltaic power generation unit 10 through the heat exchange pipeline 22, thereby increasing the working temperature difference of the thermovoltaic power generation unit 10 and improving the power generation efficiency.

[0062] According to an embodiment of the present invention, on the other hand, there is also provided a method for operating a thermovoltaic power generation system with a large temperature difference across seasons, comprising the following steps:

[0063] When the outdoor temperature is lower than the set value:

[0064] The air cooling unit 32 is connected to the main cooling pipeline 31, and uses the cold energy in the environment to cool down the heat release side of the thermovoltaic power generation unit 10;

[0065] The heat absorbing side of the thermovoltaic power generation unit 10 is heated by the heating unit, and the thermovoltaic power generation unit 10 generates electricity by using the temperature difference and supplies the electricity to the power user 40;

[0066] The heat exchange component 332 is used to store the natural cold from the outside in the underground cold storage structure 331;

[0067] When the outdoor temperature is higher than the set value:

[0068] The underground cooling unit 33 is connected to the main cooling pipeline 31, and the cold energy stored in the underground cold storage structure 331 is used to cool down the heat release side of the thermovoltaic power generation unit 10;

[0069] The heat absorbing side of the thermovoltaic power generation unit 10 is heated by the heating unit, and the thermovoltaic power generation unit 10 generates electricity by utilizing the temperature difference and supplies the electricity to the power user 40 .

[0070] The operating method of the cross-seasonal large temperature difference thermovoltaic power generation system provided by the embodiment of the present invention introduces the cross-seasonal natural cold in winter into the ground through the heat exchange component 332 as a natural cold source, and stores the cold through the underground cold storage structure 331 as a cold source in summer, thereby increasing the temperature difference between the cold and hot sources of the thermovoltaic power generation unit 10, improving the power generation efficiency of the thermovoltaic power generation unit 10, and having a low cold storage cost and high safety. The present invention can convert low-grade cold energy into high-grade electrical energy, thereby improving energy utilization; and regardless of winter or summer, the cold and hot sources of the thermovoltaic power generation unit 10 are in large temperature difference operation, which can ensure efficient power generation of the power generation system throughout the year; the cost of passive cold storage is low, and the economic efficiency of the thermovoltaic power generation system is high, which has the value of large-scale promotion.

[0071] In addition, because the operation method of the thermovoltaic power generation system with a large temperature difference across seasons utilizes the thermovoltaic power generation system with a large temperature difference across seasons described in any one of the above embodiments, it has the same effect as the thermovoltaic power generation system with a large temperature difference across seasons, and will not be repeated here.

[0072] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A thermovoltaic power generation system with large temperature difference across seasons, characterized in that: include: A thermovoltaic power generation unit (10), the thermovoltaic power generation unit (10) comprising a heat absorbing side and a heat releasing side; A heating unit, the heating unit being connected to a heat absorption side of the thermovoltaic power generation unit (10) for heat exchange; A cooling unit, the cooling unit comprising a total cooling pipeline (31), an air cooling unit (32), an underground cooling unit (33) and a reversing valve group (34); the total cooling pipeline (31) and the heat release side of the thermovoltaic power generation unit (10) are connected for heat exchange; the underground cooling unit (33) comprises an underground cold storage structure (331) and a heat exchange component (332); when the outdoor temperature is lower than a set value, the underground cold storage structure (331) is suitable for exchanging heat with the external environment through the heat exchange component (332) to store cold energy; The reversing valve group (34) selectively connects the air cooling unit (32) or the underground cooling unit (33) to the main cooling pipeline (31); When the outdoor temperature is lower than a set value, the air cooling unit (32) is connected to the main cooling pipeline (31); When the outdoor temperature is higher than a set value, the underground cooling unit (33) is connected to the main cooling pipeline (31).

2. The inter-seasonal large temperature difference thermovoltaic power generation system according to claim 1 is characterized in that: The heat exchange component (332) comprises a plurality of vertically arranged one-way gravity heat pipes (3321), the lower ends of the one-way gravity heat pipes (3321) extending into the interior of the underground cold storage structure (331), and the upper ends of the one-way gravity heat pipes (3321) extending above the ground, and the one-way gravity heat pipes (3321) are used to circulate a low-boiling-point phase-change working fluid.

3. The inter-seasonal large temperature difference thermovoltaic power generation system according to claim 2 is characterized in that: The heat exchange component (332) further comprises a plurality of heat exchange fins (3322), wherein the heat exchange fins (3322) are arranged at the top end of the unidirectional gravity heat pipe (3321) and / or the bottom end of the unidirectional gravity heat pipe (3321).

4. The thermovoltaic power generation system with a large temperature difference across seasons according to any one of claims 1 to 3, characterized in that: The underground cold storage structure (331) includes an underground energy storage water body.

5. The thermovoltaic power generation system with a large temperature difference across seasons according to any one of claims 1 to 3, characterized in that: The underground cooling unit (33) further comprises an underground cooling branch (333), wherein the underground cooling branch (333) passes through the underground cold storage structure (331); The reversing valve group (34) comprises a first three-way valve (341) and a second three-way valve (342); The upstream end of the underground cooling branch (333) is connected to the main cooling pipeline (31) via a first three-way valve (341), and the downstream end of the underground cooling branch (333) is connected to the main cooling pipeline (31) via a second three-way valve (342); And / or, the air cooling unit (32) comprises an air cooling branch (321) and an air cooler (322) connected to the air cooling branch (321); The reversing valve group (34) comprises a third three-way valve (343) and a fourth three-way valve (344); The upstream end of the air cooling branch (321) is connected to the main cooling pipeline (31) via a third three-way valve (343), and the downstream end of the air cooling branch (321) is connected to the main cooling pipeline (31) via a fourth three-way valve (344).

6. The thermovoltaic power generation system with a large temperature difference across seasons according to any one of claims 1 to 3, characterized in that: The thermovoltaic power generation unit (10) comprises a thermovoltaic power generation plate (11), and the thermovoltaic power generation plate (11) comprises a positive electrode plate and a negative electrode plate, the side where the positive electrode plate is located is the heat release side, and the side where the negative electrode plate is located is the heat absorption side.

7. The inter-seasonal large temperature difference thermovoltaic power generation system according to claim 6 is characterized in that: A plurality of the thermovoltaic power generation panels (11) are provided, and the plurality of the thermovoltaic power generation panels (11) are distributed in parallel in an umbrella shape.

8. The inter-seasonal large temperature difference thermovoltaic power generation system according to claim 7 is characterized in that: The thermovoltaic power generation unit (10) further comprises a heat distributor (12), wherein the heat distributor (12) is used to distribute cold or heat to each of the thermovoltaic power generation panels (11).

9. The inter-seasonal large temperature difference thermovoltaic power generation system according to claim 6, characterized in that: The thermovoltaic power generation unit (10) further comprises a power collector (13), wherein the power collector (13) is used to collect the power generated by the thermovoltaic power generation panel (11), and the power collector (13) supplies power to a power user (40) via a power line.

10. A method for operating a thermovoltaic power generation system with a large temperature difference across seasons, characterized in that: The following steps are involved: When the outdoor temperature is lower than the set value: The air cooling unit (32) is connected to the main cooling pipeline (31) to use the cold energy in the environment to cool down the heat release side of the thermovoltaic power generation unit (10); A heating unit is used to heat the heat absorbing side of the thermovoltaic power generation unit (10), and the thermovoltaic power generation unit (10) generates electricity by using a temperature difference and supplies electricity to a power user (40); Using a heat exchange component (332) to store the natural cold from the outside in an underground cold storage structure (331); When the outdoor temperature is higher than the set value: The underground cooling unit (33) is connected to the main cooling pipeline (31), and the cold energy stored in the underground cold storage structure (331) is used to cool the heat release side of the thermovoltaic power generation unit (10); A heating unit is used to heat the heat absorbing side of the thermovoltaic power generation unit (10), and the thermovoltaic power generation unit (10) generates electricity by utilizing temperature difference and supplies the electricity to a power user (40).

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