Clean zero-carbon energy storage system for replacing fossil fuel combustion device

Abstract

The utility model discloses a clean zero-carbon energy storage system replacing a fossil fuel combustion device, and relates to the field of fossil fuel combustion device energy-saving transformation, the clean zero-carbon energy storage system comprises a first fused salt loop, a second fused salt loop and a steam loop, the first fused salt loop comprises an electric heater, an inlet of the electric heater is connected with a low-temperature fused salt storage tank, and an outlet of the electric heater is connected with a low-temperature fused salt storage tank; an outlet of the electric heater is connected with a high-temperature fused salt storage tank, an outlet of the high-temperature fused salt storage tank is connected with a fused salt heat exchanger, and an outlet of the fused salt heat exchanger is connected with an inlet of the low-temperature fused salt storage tank. Fused salt is heated through photovoltaic power generation or wind power generation to form an energy storage system, so that efficient utilization and zero carbon emission of renewable clean energy can be realized; and meanwhile, the first fused salt loop is added to replace an original fossil fuel burner, efficient storage and release of energy are achieved through the design of the double fused salt loops, and intermittent power supply of renewable energy sources is converted into continuous and stable heat energy output.

Description

Technical Field

[0001] This utility model relates to a clean zero-carbon energy storage system that can replace fossil fuel combustion devices, and belongs to the field of energy-saving retrofit of fossil fuel combustion devices. Background Technology

[0002] Molten salt thermal energy storage is a sensible heat storage technology. Its basic principle is to store heat by utilizing the temperature change of molten salt. Molten salt thermal energy storage is divided into two working processes: heat storage and heat release. The heat storage process involves heating molten salt to store electrical or thermal energy, while the heat release process involves releasing thermal or electrical energy to the outside through high-temperature molten salt in the heat exchange system.

[0003] There is an existing molten salt thermal storage system, such as Figure 2 As shown, the system consists of a molten salt circuit and a steam circuit. The burner heats the molten salt by burning fossil fuels. The heated high-temperature molten salt then transfers its heat to the low-temperature steam from the heating production line via a molten salt steam heat exchanger. The low-temperature steam is then reheated and returns to the production line to continue supplying heat. The molten salt, after heat exchange, cools down and flows back to the molten salt tank. A molten salt pump then transports the low-temperature molten salt back to the burner, completing the system cycle. This system burns non-renewable fossil fuels 24 hours a day, resulting in high energy consumption, low efficiency, and significant emissions of greenhouse gases such as carbon dioxide and nitrogen oxides. Furthermore, traditional fossil fuel replacement devices fail to adequately consider the characteristics of intermittent renewable energy sources such as photovoltaics and wind power. They cannot effectively address the problem of excess photovoltaic power generation at midday and the energy absorption issues during peak wind power output at night, leading to high wind and solar curtailment rates. They also struggle to meet the rigid demand for a continuous and stable 24-hour steam supply in industrial sectors.

[0004] Therefore, it is necessary to improve the original system and develop a clean zero-carbon energy storage system that deeply integrates renewable energy power supply and molten salt thermal energy storage technology to achieve efficient utilization of clean energy and a continuous and stable supply of industrial energy. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned problems by providing a clean, zero-carbon energy storage system that replaces fossil fuel combustion devices. This system utilizes photovoltaic or wind power to heat molten salt, forming an energy storage system that enables efficient utilization of renewable clean energy and zero carbon emissions. Furthermore, it adds a first molten salt circuit to replace the original fossil fuel burner, employing a dual molten salt circuit design to achieve efficient energy storage and release, converting intermittent renewable energy power supply into continuous and stable heat output. This design meets the requirement of continuous 24-hour operation for steam production lines, while also efficiently utilizing green electricity and reducing wind and solar curtailment. Additionally, the heat buffering effect of the high-temperature molten salt storage tank significantly improves the overall system's operational reliability.

[0006] The technical solution adopted by this utility model is as follows: it includes a first molten salt circuit, a second molten salt circuit and a steam circuit. The first molten salt circuit includes an electric heater. The inlet of the electric heater is connected to a low-temperature molten salt storage tank. The outlet of the electric heater is connected to a high-temperature molten salt storage tank. The outlet of the high-temperature molten salt storage tank is connected to a molten salt heat exchanger. The outlet of the molten salt heat exchanger is connected to the inlet of the low-temperature molten salt storage tank.

[0007] Alternatively, the power input terminal of the electric heater can be connected to a photovoltaic power generation system or a wind power generation system.

[0008] Optionally, the high-temperature molten salt storage tank may be provided with an insulation structure inside and / or outside.

[0009] Alternatively, the insulation structure may be made of high-efficiency thermal insulation materials such as ceramic fiber or aluminum silicate.

[0010] Alternatively, the second molten salt circuit includes the molten salt heat exchanger, the outlet of which is connected to a molten salt steam heat exchanger, the inlet of which is connected to a molten salt tank, and the outlet of which is connected to the inlet of the molten salt steam heat exchanger.

[0011] Alternatively, both the molten salt heat exchanger and the molten salt steam heat exchanger may be tubular heat exchangers.

[0012] Alternatively, the outlet of the molten salt tank is connected to a molten salt pump, and the outlet of the molten salt pump is connected to the inlet of the molten salt heat exchanger.

[0013] Alternatively, the steam circuit may include the molten salt steam heat exchanger and a steam pipeline connected to an industrial production line.

[0014] Alternatively, the outlet of the high-temperature molten salt storage tank is connected to a high-temperature molten salt pump, and the outlet of the high-temperature molten salt pump is connected to the inlet of the molten salt heat exchanger.

[0015] Alternatively, the outlet of the cryogenic molten salt storage tank is connected to a cryogenic molten salt pump, and the outlet of the cryogenic molten salt pump is connected to the inlet of the electric heater.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0017] 1. The present invention provides a clean zero-carbon energy storage system that replaces fossil fuel combustion devices. It uses photovoltaic power generation or wind power generation to heat molten salt to form an energy storage system, thereby achieving efficient utilization of renewable clean energy and zero carbon emissions.

[0018] 2. This utility model provides a clean zero-carbon energy storage system that replaces fossil fuel combustion devices. It adds a first molten salt circuit to replace the original fossil fuel burner and employs a dual molten salt circuit design to achieve efficient energy storage and release, converting intermittent power supply from renewable energy sources into continuous and stable heat output. This design can meet the requirement of continuous 24-hour operation for steam production lines, while also efficiently utilizing green electricity and reducing wind and solar curtailment. Furthermore, the heat buffering effect of the high-temperature molten salt storage tank significantly improves the operational reliability of the entire system. Attached Figure Description

[0019] Figure 1 This is a system flowchart of this utility model;

[0020] Figure 2 This is the original system flowchart;

[0021] The diagram is labeled as follows: 1-First molten salt circuit; 11-Electric heater; 12-High-temperature molten salt storage tank; 13-Molten salt heat exchanger; 14-Low-temperature molten salt storage tank; 15-High-temperature molten salt pump; 16-Low-temperature molten salt pump; 2-Second molten salt circuit; 21-Fossil fuel burner; 22-Molten salt steam heat exchanger; 23-Molten salt tank; 24-Molten salt pump; 3-Steam circuit. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings.

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0024] A clean, zero-carbon energy storage system to replace fossil fuel combustion devices, such as Figure 1As shown, it includes a first molten salt circuit 1, a second molten salt circuit 2, and a steam circuit 3. The function of the first molten salt circuit 1 is to store heat, converting green electricity such as photovoltaic and wind power into thermal energy for storage; the function of the second molten salt circuit 2 is to release heat, transferring the heat received from the first molten salt circuit 1 to the steam system; the steam circuit 3 connects to the production line to supply energy. The first molten salt circuit 1 includes an electric heater 11, which converts electrical energy from green electricity such as photovoltaic and wind power into heat energy, and raises the temperature of the molten salt to the designed high temperature through resistance heating. The inlet of the electric heater 11 is connected to a low-temperature molten salt storage tank 14, which is used to store low-temperature molten salt. The outlet of the electric heater 11 is connected to a high-temperature molten salt storage tank 12, which stores high-temperature molten salt. Part of the molten salt is stored as a reserve to release heat when the power supply is interrupted, thereby realizing the continuous operation of the system. The other molten salt is transported to a molten salt heat exchanger 13 to exchange heat with the low-temperature molten salt in the second molten salt circuit 2. The outlet of the high-temperature molten salt storage tank 12 is connected to the molten salt heat exchanger 13, and the outlet of the molten salt heat exchanger 13 is connected to the inlet of the low-temperature molten salt storage tank 14. The molten salt heat exchanger 13 is used to transfer part of the heat from the high-temperature molten salt to the second molten salt circuit 2. After the heat transfer is completed, the cooled molten salt flows back to the low-temperature storage tank, forming a closed loop. Compared to the original system, this design adds a first molten salt circuit 1 to replace the original fossil fuel burner 21, enabling efficient utilization of renewable clean energy and zero carbon emissions. Simultaneously, by adhering to the principle of maximizing the reuse of existing energy, the original system layout is preserved to the greatest extent possible, reducing costs. Compared to the single-circuit design that eliminates the first molten salt circuit 1 and directly connects to the electric heater 11 in the second molten salt circuit 2, this design, through a dual-circuit design, utilizes the heat storage during periods of wind and solar power curtailment, enabling the cross-period consumption of green electricity; ensuring 24-hour continuous operation of the steam system; and achieving peak shaving and valley filling of green electricity, solving the problems of energy supply fluctuations and uncontrollable costs caused by real-time heating in traditional single-circuit systems.

[0025] In one alternative implementation, the power input terminal of the electric heater 11 is connected to a photovoltaic power generation system or a wind power generation system. Both photovoltaic and wind power are clean energy sources, and using clean energy to generate electricity can achieve zero carbon emissions and reduce pollution. During peak photovoltaic periods (midday), wind power output is generally higher at night. At this time, the surplus photovoltaic or wind power is used to heat molten salt via the electric heater 11 and stored in a high-temperature molten salt storage tank 12. This stored salt is released when power is unavailable, effectively solving the energy consumption problem of peak photovoltaic power generation at midday and peak wind power output at night, and meeting the rigid demand for a continuous and stable 24-hour steam supply in the industrial sector. As another alternative implementation, the power input terminal of the electric heater 11 can also be connected to clean energy sources such as hydropower or hydrogen energy, and can also access low-priced off-peak electricity during off-peak hours to reduce costs.

[0026] In one alternative implementation, the high-temperature molten salt storage tank 12 is equipped with an insulation structure inside and / or outside. This insulation structure maintains the temperature of the high-temperature molten salt in the tank, ensuring a continuous supply of heat even when power is unavailable, thus meeting the requirement for a 24-hour continuous and stable steam supply. The insulation structure can be located inside or outside the high-temperature molten salt storage tank 12, or, to improve insulation performance, both can be installed inside and outside simultaneously. Furthermore, the insulation structure can be achieved by covering the inner and / or outer walls of the high-temperature molten salt storage tank 12 with insulating refractory material, or by installing an electric heater 11 or laying heating cables in the tank for heat tracing and insulation. Insulating refractory material reduces heat loss through material insulation but cannot completely prevent it; it is low-cost and suitable for mild environments or short-term shutdowns. Electric heating / heat tracing systems actively compensate for heat loss, maintaining a constant temperature; they are more expensive but also highly stable, making them suitable for extreme environments or long-term operation. In large-scale energy storage systems, insulation materials can be combined with localized heating to balance cost, safety, and efficiency.

[0027] One alternative implementation involves using either high-efficiency thermal insulation materials such as ceramic fiber or aluminosilicate. Ceramic fiber is better suited for extreme high-temperature, neutral / weakly alkaline molten salt environments, and for cost-sensitive projects; aluminosilicate fiber offers advantages in thermal shock resistance, acidic molten salt resistance, and environmental friendliness, making it suitable for scenarios requiring high long-term stability.

[0028] In one alternative implementation, the second molten salt circuit 2 includes the molten salt heat exchanger 13, the outlet of which is connected to a molten salt steam heat exchanger 22. The molten salt steam heat exchanger 22 is used to transfer the heat from the high-temperature molten salt in the second molten salt circuit 2 to the steam circuit 3. The inlet of the molten salt heat exchanger 13 is connected to a molten salt tank 23, and the outlet of the molten salt steam heat exchanger 22 is connected to the inlet of the molten salt tank 23. The molten salt tank 23 is used to store the low-temperature molten salt after heat exchange.

[0029] In one alternative embodiment, both the molten salt heat exchanger 13 and the molten salt steam heat exchanger 22 are tubular heat exchangers. The shell of the tubular heat exchanger contains several parallel pipes, through which molten salt flows, exchanging heat through the pipe walls. The tube bundles can be arranged in a single-pass or multi-pass configuration to increase the heat transfer area and improve heat exchange efficiency. Tubular heat exchangers are commonly used devices in the art and belong to existing technology; their specific structure and heat exchange methods will not be described in detail in this specification. Alternatively, the molten salt heat exchanger 13 and the molten salt steam heat exchanger 22 can also be plate heat exchangers or heat pipe heat exchangers. Tubular heat exchangers have a simple structure, strong adaptability, and large processing capacity, making them suitable for high-temperature and high-pressure conditions. However, they are bulky, require more materials, and have relatively low heat transfer efficiency. Plate heat exchangers have a higher heat transfer coefficient, occupy less space, and are easier to install, but their pressure-bearing capacity is limited, and they are prone to clogging, requiring more frequent cleaning and maintenance. Heat pipe heat exchangers have extremely high heat transfer efficiency, good isothermal performance, can operate with small temperature differences, and are easy to maintain. However, they are expensive and have complex manufacturing processes.

[0030] In one alternative implementation, the outlet of the molten salt tank 23 is connected to a molten salt pump 24, and the outlet of the molten salt pump 24 is connected to the inlet of the molten salt heat exchanger 13. The molten salt pump 24 is used to pump the low-temperature molten salt from the molten salt tank 23 into the molten salt heat exchanger 13 to provide kinetic energy for the molten salt flow.

[0031] In one alternative implementation, the steam circuit 3 includes the molten salt steam heat exchanger 22 and a steam pipe connected to the industrial production line. The high-temperature molten salt transfers heat to the low-temperature steam coming from the heating production line through the molten salt steam heat exchanger 22. The low-temperature steam is heated and then returns to the production line to continue supplying heat.

[0032] In one alternative implementation, the outlet of the high-temperature molten salt storage tank 12 is connected to a high-temperature molten salt pump 15, and the outlet of the high-temperature molten salt pump 15 is connected to the inlet of the molten salt heat exchanger 13. The high-temperature molten salt pump 15 is used to pump a portion of the high-temperature molten salt in the high-temperature molten salt storage tank 12 into the molten salt heat exchanger 13 for heat exchange.

[0033] In one alternative embodiment, the outlet of the cryogenic molten salt storage tank 14 is connected to a cryogenic molten salt pump 16, and the outlet of the cryogenic molten salt pump 16 is connected to the inlet of the electric heater 11. The cryogenic molten salt pump 16 is used to pump the cryogenic molten salt in the cryogenic molten salt storage tank 14 into the electric heater 11 for heating.

[0034] The operation process of the embodiment provided is as follows: During the power generation period, in the first molten salt circuit 1, the molten salt in the low-temperature molten salt storage tank 14 is transported to the electric heater 11 for heating by the low-temperature molten salt pump 16. The heated high-temperature molten salt enters the high-temperature molten salt storage tank 12, where part of the molten salt is stored for later use. The other molten salt is transported to the molten salt heat exchanger 13 by the high-temperature molten salt pump 15 to exchange heat with the low-temperature molten salt in the second molten salt circuit 2. The temperature of the molten salt in the first molten salt circuit 1 decreases after heat exchange and enters the low-temperature molten salt storage tank 14. The low-temperature molten salt in the low-temperature molten salt storage tank 14 enters the electric heater 11 again by the low-temperature molten salt pump 16, thus completing the heat exchange cycle of the first molten salt circuit 1. In the second molten salt circuit 2, the heated high-temperature molten salt transfers heat to the low-temperature steam from the heating production line through the molten salt steam heat exchanger 22. The low-temperature steam is heated and returns to the production line to continue supplying heat, while the temperature of the molten salt decreases after heat exchange and flows back to the molten salt tank 23. The low-temperature molten salt in the molten salt tank 23 enters the molten salt heat exchanger 13 through the molten salt pump 24, thus completing the heat exchange cycle of the second molten salt circuit 2.

[0035] To ensure continuous 24-hour operation of the system, during photovoltaic or hydropower generation, the electric heater 11 operates continuously, and the molten salt storage in the high-temperature molten salt storage tank 12 continuously increases, storing heat. When power is unavailable, the system releases heat, the electric heater 11 stops operating, the low-temperature molten salt pump 16 stops operating, and the high-temperature molten salt pump 15 continues to operate, transporting the stored high-temperature molten salt to the molten salt heat exchanger 13 for heat exchange with the production line's molten salt system. The cooled low-temperature molten salt continuously returns to the low-temperature molten salt storage tank 14, and the low-temperature molten salt storage continuously increases until photovoltaic or hydropower generation is put into operation, at which point the low-temperature molten salt pump 16 is put into operation, and the heat storage cycle begins again.

[0036] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. The present utility model extends to any new features or combinations disclosed in this specification, and 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. It is obvious to those skilled in the art that the present utility model is not limited to the details of the above exemplary embodiments, and that detailed technical features not disclosed in this embodiment, such as specific structures and connection methods, are all prior art, which can be obtained by those skilled in the art from the prior art. The present disclosure does not specifically limit these aspects.

[0037] In the description of the embodiments of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this utility model, "multiple" means two or more, unless otherwise explicitly specified.

[0038] In this embodiment of the invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention according to the specific circumstances.

Claims

1. A clean, zero-carbon energy storage system that replaces fossil fuel combustion devices, characterized in that: It includes a first molten salt circuit (1), a second molten salt circuit (2), and a steam circuit (3). The first molten salt circuit (1) includes an electric heater (11). The inlet of the electric heater (11) is connected to a low-temperature molten salt storage tank (14). The outlet of the electric heater (11) is connected to a high-temperature molten salt storage tank (12). The outlet of the high-temperature molten salt storage tank (12) is connected to a molten salt heat exchanger (13). The outlet of the molten salt heat exchanger (13) is connected to the inlet of the low-temperature molten salt storage tank (14).

2. The clean zero-carbon energy storage system for replacing fossil fuel combustion devices according to claim 1, characterized in that: The power input terminal of the electric heater (11) is connected to a photovoltaic power generation system or a wind power generation system.

3. The clean zero-carbon energy storage system for replacing fossil fuel combustion devices according to claim 1, characterized in that: The high-temperature molten salt storage tank (12) is provided with an insulation structure inside and / or outside.

4. The clean zero-carbon energy storage system for replacing fossil fuel combustion devices according to claim 3, characterized in that: The insulation structure is made of high-efficiency thermal insulation materials such as ceramic fiber or aluminum silicate.

5. The clean zero-carbon energy storage system for replacing fossil fuel combustion devices according to claim 1, characterized in that: The second molten salt circuit (2) includes the molten salt heat exchanger (13), the outlet of the molten salt heat exchanger (13) is connected to the molten salt steam heat exchanger (22), the inlet of the molten salt heat exchanger (13) is connected to the molten salt tank (23), and the outlet of the molten salt steam heat exchanger (22) is connected to the inlet of the molten salt tank (23).

6. The clean zero-carbon energy storage system for replacing fossil fuel combustion devices according to claim 5, characterized in that: Both the molten salt heat exchanger (13) and the molten salt steam heat exchanger (22) are tubular heat exchangers.

7. The clean zero-carbon energy storage system for replacing fossil fuel combustion devices according to claim 5, characterized in that: The outlet of the molten salt tank (23) is connected to a molten salt pump (24), and the outlet of the molten salt pump (24) is connected to the inlet of the molten salt heat exchanger (13).

8. The clean zero-carbon energy storage system for replacing fossil fuel combustion devices according to claim 5, characterized in that: The steam circuit (3) includes the molten salt steam heat exchanger (22) and a steam pipeline connected to the industrial production line.

9. The clean zero-carbon energy storage system for replacing fossil fuel combustion devices according to claim 1, characterized in that: The outlet of the high-temperature molten salt storage tank (12) is connected to a high-temperature molten salt pump (15), and the outlet of the high-temperature molten salt pump (15) is connected to the inlet of the molten salt heat exchanger (13).

10. The clean zero-carbon energy storage system for replacing fossil fuel combustion devices according to claim 1, characterized in that: The outlet of the cryogenic molten salt storage tank (14) is connected to a cryogenic molten salt pump (16), and the outlet of the cryogenic molten salt pump (16) is connected to the inlet of the electric heater (11).

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