Refrigeration and heating cycle system coupled with carbon dioxide energy storage

Abstract

The application provides a refrigeration and heat supply cycle system coupled with carbon dioxide energy storage, and relates to the technical field of energy storage cycles.The refrigeration and heat supply cycle system is based on the transformation of the critical state of carbon dioxide, and the energy storage cycle is performed by taking carbon dioxide as a working medium.The cold and heat self-circulation of the refrigeration and heat supply cycle system is performed through heat exchange.The cold and heat storage module is coupled with the carbon dioxide sub-energy storage module through an energy storage heat exchanger to perform internal heat exchange of the refrigeration and heat supply cycle system.The carbon dioxide sub-energy storage module exchanges heat with external energy.The refrigeration and heat supply module is coupled with the carbon dioxide sub-energy storage module through a refrigeration and heat supply heat exchanger to perform heat exchange between the refrigeration and heat supply cycle system and the external environment.The problems of low energy utilization rate, great environmental impact, low system efficiency, and unstable energy utilization of the energy storage cycle system are solved, the system efficiency is improved, the stability of the overall system energy supply is ensured, and the effect of achieving zero carbonization is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage cycles, in particular to a refrigeration and heating cycle system coupled with carbon dioxide energy storage. BACKGROUND

[0002] With the change of global energy structure and the improvement of environmental protection demand, using clean energy for efficient energy conversion and storage has become a hot spot in research and industry. In the field of energy conversion, especially in refrigeration and heating systems, traditional systems relying on fossil fuels are gradually being replaced by renewable energy-driven systems. However, due to the high dependence and instability of renewable energy such as wind and solar energy, how to effectively store these energy and release it efficiently when needed has become a technical challenge. And current energy storage systems, such as pumped storage and compressed air energy storage, although they have shown potential in some commercial applications, they are often limited by geographical location, and the equipment is large in size and low in energy density, which is not suitable for widespread promotion. In addition, traditional refrigeration and heating systems often use freon and other working fluids, which are not only harmful to the environment, but also exacerbate global warming. Although some technologies propose to use carbon dioxide as a working fluid for energy storage cycles, the technical direction is relatively scattered, and at the same time, the energy conversion efficiency of existing refrigeration and heating technologies is often limited by the use of working fluids and the limitations of technology, which cannot truly realize the integration of storage and use, and the integration of cold and heat, resulting in high equipment investment cost, long payback period, and not conducive to the economic benefits and stable and sustainable operation of the overall system.

[0003] In summary, the existing energy storage cycle system often has the technical problems of low energy utilization rate, large environmental impact, low system efficiency, and unstable energy utilization, which further limits the widespread application and economic benefits of the system. SUMMARY

[0004] The present application provides a refrigeration and heating cycle system coupled with carbon dioxide energy storage, which is used to solve the technical problems of low energy utilization rate, large environmental impact, low system efficiency, and unstable energy utilization of existing energy storage cycle systems, which further limits the widespread application and economic benefits of the system.

[0005] The present application provides a refrigeration and heating cycle system coupled with carbon dioxide energy storage, which comprises:

[0006] The carbon dioxide sub-energy storage module is used for energy storage cycle based on the transformation of the critical state of carbon dioxide with carbon dioxide as the working medium; the cold and heat self-circulation in the refrigeration and heating cycle system is realized through heat exchange; the first coupling heat exchange module is used for coupling the cold and heat storage module to the carbon dioxide sub-energy storage module through an energy storage heat exchanger to realize the internal heat exchange of the refrigeration and heating cycle system; the refrigeration and heating module is used for heat exchange between the carbon dioxide sub-energy storage module and external energy; and the second coupling heat exchange module is used for coupling the refrigeration and heating module to the carbon dioxide sub-energy storage module through a refrigeration and heating heat exchanger to realize the heat exchange between the refrigeration and heating cycle system and the outside.

[0007] The carbon dioxide sub-energy storage module is used for energy storage cycle based on the transformation of the critical state of carbon dioxide with carbon dioxide as the working medium; the cold and heat self-circulation in the refrigeration and heating cycle system is realized through heat exchange; the first coupling heat exchange module is used for coupling the cold and heat storage module to the carbon dioxide sub-energy storage module through an energy storage heat exchanger to realize the internal heat exchange of the refrigeration and heating cycle system; the refrigeration and heating module is used for heat exchange between the carbon dioxide sub-energy storage module and external energy; and the second coupling heat exchange module is used for coupling the refrigeration and heating module to the carbon dioxide sub-energy storage module through a refrigeration and heating heat exchanger to realize the heat exchange between the refrigeration and heating cycle system and the outside. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 The structure diagram of the refrigeration and heating cycle system coupled with carbon dioxide energy storage provided by the embodiment of the application is shown in the figure.

[0009] Figure 2 The energy flow structure diagram of the refrigeration and heating cycle system coupled with carbon dioxide energy storage provided by the embodiment of the application is shown in the figure.

[0010] Explanation of reference numerals in the attached drawings: Carbon dioxide sub-energy storage module 11, cold and heat storage module 12, first coupled heat exchange module 13, cooling and heating module 14, second coupled heat exchange module 15, third heat exchanger 10, fourth heat exchanger 20, first heat exchanger 30, second heat exchanger 40, hot water tank 50, cold water tank 60, low-pressure tank 70, high-pressure tank 80, energy storage compressor 90, heating compressor 100, cooling compressor 110, heating throttling valve 120, cooling throttling valve 130, condenser 140, evaporator 150, turbine machinery 160. Detailed Implementation

[0011] To make the purpose, technical solution, and advantages of this application clearer, the following description is provided in conjunction with the appendix. Figure 1 , 2 The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

[0012] A refrigeration and heating cycle system is a system capable of simultaneously providing cooling and heating functions. These systems primarily rely on thermodynamic cycles to transfer heat, allowing one environment to be cooled while another is simultaneously heated. The advantages of this type of system include high energy efficiency, multi-functionality (i.e., the same system can be used for both cooling and heating), and greater environmental friendliness than traditional heating and cooling systems. Among the energy storage methods for refrigeration and heating cycle systems, the megawatt-level, long-term energy storage technologies currently achieving commercial application mainly include pumped hydro storage and compressed air energy storage. Carbon dioxide energy storage, as a type of compressed air energy storage, benefits from the fact that air has a critical point of 3.77 MPa and -140.5°C, while carbon dioxide only requires 7.39 MPa and 31.4°C. It has more favorable critical conditions than air, and supercritical carbon dioxide possesses excellent thermophysical properties such as low viscosity and high density, allowing for energy storage using small and simple impeller machinery and heat transfer units. Meanwhile, carbon dioxide possesses excellent thermal stability, non-toxicity, non-flammability, and zero ozone depletion, making it a potential environmentally friendly alternative to conventional refrigerants such as Freon and R134a. Therefore, since liquefaction is easier to achieve than air, this application uses carbon dioxide as the working fluid for energy storage research. Furthermore, liquid carbon dioxide energy storage is not limited by harsh geographical conditions, and its main equipment is small in size with high energy density, making it suitable for large-scale commercial deployment and more in line with the requirements of zero-carbon technology systems.

[0013] This application provides a refrigeration and heating cycle system coupled with carbon dioxide energy storage, such as... Figure 1 As shown, the system includes:

[0014] The carbon dioxide sub-energy storage module 11 is used to perform energy storage cycles based on the transition of the critical state of carbon dioxide, using carbon dioxide as the working fluid.

[0015] The cold and heat storage module 12 is used for cold and heat self-circulation inside the refrigeration and heating circulation system through heat exchange.

[0016] The first coupling heat exchange module 13 is used for coupling the cold and heat storage module to the carbon dioxide sub-energy storage module through the energy storage heat exchanger for internal heat exchange of the refrigeration and heating circulation system.

[0017] The refrigeration and heating module 14 is used for heat exchange of the carbon dioxide sub-energy storage module and external energy.

[0018] The second coupling heat exchange module 15 is used for coupling the refrigeration and heating module to the carbon dioxide sub-energy storage module through the refrigeration and heating heat exchanger for heat exchange between the refrigeration and heating circulation system and the outside.

[0019] Further, the refrigeration and heating heat exchanger comprises a first heat exchanger 30 and a second heat exchanger 40, and the energy storage heat exchanger comprises a third heat exchanger 10 and a fourth heat exchanger 20.

[0020] Specifically, the present application proposes a refrigeration and heating cycle system using carbon dioxide as the working medium. The system realizes energy storage and release through efficient energy storage and heat exchange mechanisms, adapting to the dual requirements of environmental protection and energy efficiency. The system mainly includes five core modules: carbon dioxide sub-energy storage module, cold and heat storage module, first coupling heat exchange module, refrigeration and heating module, and second coupling heat exchange module. The core function of the carbon dioxide sub-energy storage module is to use carbon dioxide as the working medium to store and release energy through its physical property changes at the critical state. In this module, carbon dioxide crosses its critical point during compression and expansion to achieve high efficiency of energy conversion. The transition of this critical state allows carbon dioxide to store a large amount of energy with a small volume change, thereby improving the energy storage density and overall energy efficiency of the system. The cold and heat storage module uses an energy storage heat exchanger to achieve internal cold and heat self-circulation. In this process, the thermal energy of carbon dioxide is used for refrigeration or heating, depending on the system's operating mode. The design of the cold and heat storage module allows the system to flexibly adjust the output of cold and heat in different seasons and environmental conditions, avoiding additional cold and heat sources, improving the energy storage efficiency of the system, increasing the overall economy, and meeting different user demands. The first coupling heat exchange module couples the cold and heat storage module with the carbon dioxide sub-energy storage module through the energy storage heat exchanger, i.e., the third heat exchanger 10 and the fourth heat exchanger 20. In this step, the third heat exchanger 10 provides heat to the low-pressure tank 70 to warm up the low-temperature and low-pressure carbon dioxide gas released from the low-pressure tank 70. The warmed carbon dioxide gas carries away the heat, causing the hot water to become cold water and flow to the cold water tank. The fourth heat exchanger 20 is designed to remove heat from the carbon dioxide sub-energy storage module. The refrigeration and heating module combines the carbon dioxide sub-energy storage module with external energy for heat exchange through the first heat exchanger 30 and the second heat exchanger 40. In heating mode, the first heat exchanger 30 cools down the high-temperature and high-pressure carbon dioxide gas in the carbon dioxide sub-energy storage module to release its high-temperature energy for heating purposes. In refrigeration mode, the second heat exchanger 40 absorbs external heat to provide heat exchange for the high-pressure and low-temperature carbon dioxide liquid in the carbon dioxide sub-energy storage module to achieve refrigeration purposes. The second coupling heat exchange module further couples the refrigeration and heating module with the carbon dioxide sub-energy storage module through the refrigeration and heating heat exchanger to optimize the heat exchange efficiency of the entire system. This design ensures that the system can operate efficiently and stably under different operating conditions while minimizing the loss of heat and cold. Through the above steps, not only the energy utilization efficiency is significantly improved, but also an environmentally friendly refrigeration and heating solution is realized, meeting the demand for efficient and environmentally friendly energy systems in modern society.

[0021] Further, the carbon dioxide sub-energy storage module 11 comprises a low-pressure tank 70, a third heat exchanger 10, an energy storage compressor 90, a first heat exchanger 30, a high-pressure tank 80, a second heat exchanger 40, a turbine 160 and a fourth heat exchanger 20 connected in sequence, and the energy storage cycle process comprises:

[0022] The low-temperature and low-pressure carbon dioxide gas released from the low-pressure tank 70 is warmed by the third heat exchanger 10, and the warmed medium-temperature and low-pressure carbon dioxide gas is pressurized by the energy storage compressor 90 to obtain high-temperature and high-pressure carbon dioxide gas.

[0023] The high-temperature and high-pressure carbon dioxide gas is cooled by the first heat exchanger 30, and the cooled high-pressure and low-temperature carbon dioxide liquid is stored in the high-pressure tank 80 to obtain stored energy.

[0024] The high-pressure and low-temperature carbon dioxide liquid flowing out of the high-pressure tank 80 is heated and warmed by the second heat exchanger 40 to obtain high-temperature and high-pressure carbon dioxide gas.

[0025] The high-temperature and high-pressure carbon dioxide gas entering the turbine 160 is used to drive the turbine to generate electricity, and the stored energy is released to obtain low-pressure and medium-temperature carbon dioxide gas.

[0026] The low-pressure and medium-temperature carbon dioxide gas is cooled by the fourth heat exchanger 20 to obtain low-temperature and low-pressure carbon dioxide gas, which is stored in the low-pressure tank 70.

[0027] Optionally, the carbon dioxide sub-energy storage module comprises, in sequence, the low-pressure tank 70, the third heat exchanger 10, the energy storage compressor 90, the first heat exchanger 30, the high-pressure tank 80, the second heat exchanger 40, the turbine 160, and the fourth heat exchanger 20. The specific energy storage cycle process is as follows: the low-temperature and low-pressure carbon dioxide gas released from the low-pressure tank 70 is first sent into the third heat exchanger 10. In the heat exchanger, the carbon dioxide gas is heated to a medium temperature by the hot water sent from the hot water tank 50. The heated medium-temperature and low-pressure carbon dioxide gas is then sent into the energy storage compressor 90, where the gas is compressed, and the temperature and pressure are significantly increased, and the gas is converted into a high-temperature and high-pressure state. The high-temperature and high-pressure carbon dioxide gas processed by the compressor is then flowed into the first heat exchanger 30. In the first heat exchanger 30, the high-temperature gas is cooled and condensed into a liquid state, and the heat released in the process can be discharged to the outside of the system, i.e., to provide heat for the heating unit. The cooled high-pressure and low-temperature carbon dioxide liquid is stored in the high-pressure tank 80, and the energy is stored in the form of compressed liquid. When the system needs to release energy, the low-temperature and high-pressure carbon dioxide liquid stored in the high-pressure tank 80 is sent into the second heat exchanger 40, where it is heated and warmed again, and is converted back into a high-temperature and high-pressure gaseous state, wherein the heating and warming process is performed by the refrigeration unit by absorbing external heat. Subsequently, the high-temperature and high-pressure gas enters the turbine 160 to drive the steam turbine to generate electricity, thereby effectively releasing the stored energy. The mechanical energy generated by the rotation of the turbine 160 can be converted into electrical energy for the system or external power grid. Finally, the low-pressure and medium-temperature carbon dioxide gas after energy release is flowed into the fourth heat exchanger 20, where it is further cooled to a low-temperature and low-pressure state by heat exchange with the cold water flowed out of the cold water tank 60, and the energy release cycle is completed. The cooled gas is stored back into the low-pressure tank 70 to prepare for the next round of energy storage cycle. This continuous process not only ensures the efficient use of energy, but also maximizes the reduction of energy loss in the conversion process, and improves the economy and environmental protection of the overall system.

[0028] Further, the cold and heat self-circulation module 12 comprises, in sequence, the hot water tank 50, the third heat exchanger 10, the cold water tank 60, and the fourth heat exchanger 20, and the cold and heat self-circulation process comprises:

[0029] The cold water flowed out of the cold water tank 60 is heated and warmed by the fourth heat exchanger 20 to obtain heated hot water, and the hot water is stored in the hot water tank 50.

[0030] The hot water flowed out of the hot water tank 50 is cooled and cooled by the third heat exchanger 10 to obtain cooled cold water, and the cold water is returned to the cold water tank 60.

[0031] For example, the cold and heat storage module is designed to realize the cold and heat self-circulation in the refrigeration and heating cycle system, thereby improving the energy efficiency and economic operation of the system. The module is composed of a hot water tank 50, a third heat exchanger 10, a cold water tank 60 and a fourth heat exchanger 20 connected in sequence. It specifically includes a cold water warming process and a hot water cooling process. In the cold water warming process, in the initial stage, cold water flows out from the cold water tank 60 and enters the fourth heat exchanger 20. In the fourth heat exchanger 20, the cold water absorbs heat and the temperature gradually rises. During this process, the design of the heat exchanger ensures efficient transfer of heat energy, so that the cold water is effectively changed into hot water. The hot water after warming is then sent to the hot water tank 50 for storage, preparing for the next step of heat energy use or further energy conversion. In the hot water cooling process, hot water flows out from the hot water tank 50 and enters the third heat exchanger 10. In this heat exchanger, the hot water releases heat, causing the water temperature to drop. The function of the third heat exchanger is to transfer the heat energy in the hot water out by using its high-efficiency heat exchange capacity, thereby reducing the water temperature and converting it into cold water. This step can flexibly supplement the energy in the carbon dioxide sub-energy storage module. Through the above cold and heat self-circulation process, the cold and heat storage module effectively manages the heat energy flow in the system, enabling the system to maintain high energy utilization rate when switching between refrigeration and heating modes. At the same time, the design of this module considers the maximum recovery and cyclic use of energy, ensuring that the system can operate continuously and stably without increasing additional energy consumption. Therefore, the cold and heat storage module not only improves the efficiency of energy use, but also meets the environmental protection requirements of energy saving and emission reduction, and is suitable for modern refrigeration and heating systems that require efficient energy management.

[0032] Further, the refrigeration and heating module 14 includes a heating unit and a refrigeration unit, wherein the heating unit includes a heating compressor 100, a condenser 140, a heating throttle valve 120 and a first heat exchanger 30 connected in sequence, and the heating exchange process with external energy includes:

[0033] The carbon dioxide gas at normal temperature and pressure is pressurized and heated by the heating compressor 100 to obtain high-temperature and high-pressure carbon dioxide gas.

[0034] The high-temperature and high-pressure carbon dioxide gas is sent into the condenser 140 to release heat and warm up, obtaining high-pressure and low-temperature carbon dioxide liquid, and the high-pressure and low-temperature carbon dioxide is depressurized and cooled by the heating throttle valve 120, and combined with the first heat exchanger 30 to absorb heat and warm up, obtaining carbon dioxide gas at normal temperature and pressure.

[0035] The carbon dioxide gas at normal temperature and pressure is continuously sent into the heating compressor 100.

[0036] Further, the refrigeration and heating module mainly consists of a heating unit and a refrigeration unit, wherein the heating unit includes a heating compressor 100, a condenser 140, a heating throttle valve 120 and a first heat exchanger 30 connected in sequence. Specifically, the operation of the heating unit starts with the heating compressor 100, which compresses and heats the carbon dioxide gas at normal temperature and pressure. Through this process, the temperature and pressure of the carbon dioxide gas increase significantly, changing to a high-temperature and high-pressure state. This step is the key to the energy conversion process, as it provides the necessary thermal energy basis for subsequent heat exchange. Next, the high-temperature and high-pressure carbon dioxide gas is sent to the condenser 140. In the condenser 140, the carbon dioxide gas releases heat to the outside, and during this process, the temperature of the carbon dioxide decreases, and a phase change occurs, changing from a gaseous state to a liquid state. The heat released in this process can be used for building heating or other thermal energy needs, achieving useful conversion of energy. The high-pressure and low-temperature carbon dioxide liquid after the condenser 140 enters the heating throttle valve 120, and at this time, the pressure and temperature are reduced through the throttle valve, and the carbon dioxide is further cooled and prepared to enter the first heat exchanger 30. In the first heat exchanger 30, the carbon dioxide liquid absorbs the heat inside the carbon dioxide sub-energy storage module, warms up and re-gases to carbon dioxide gas at normal temperature and pressure. This step not only recovers the remaining heat energy in the system, but also provides conditions for the re-compression and circulation of carbon dioxide gas. Subsequently, the heated carbon dioxide gas at normal temperature and pressure is again sent to the heating compressor 100, and a new round of energy compression and heating process is started, forming a closed loop cycle to ensure continuous use of energy and conversion efficiency. Through the above process, the heating unit can efficiently recover and recycle heat energy, optimizing the overall energy utilization efficiency and reducing environmental impact. In addition, the system design considers the continuity and stability of energy conversion, ensuring that the heating unit can operate stably under various operating conditions and meet diverse thermal energy needs.

[0037] Further, the refrigeration unit includes a refrigeration compressor 110, a second heat exchanger 40, a refrigeration throttle valve 130 and an evaporator 150 connected in sequence, and the refrigeration exchange process with external energy includes:

[0038] The carbon dioxide gas at normal temperature and pressure is compressed by the refrigeration compressor 110 to obtain high-temperature and high-pressure carbon dioxide gas.

[0039] The high-temperature and high-pressure carbon dioxide gas is cooled and cooled in the second heat exchanger 40 to obtain high-pressure and low-temperature carbon dioxide liquid.

[0040] The high-pressure and low-temperature carbon dioxide is reduced in pressure and temperature by the refrigeration throttle valve 130, and based on the evaporator 150, it absorbs heat and cools to obtain carbon dioxide gas at normal temperature and pressure, which is continuously sent to the refrigeration compressor 110.

[0041] Specifically, the refrigeration unit is used to effectively perform a refrigeration cycle to achieve cooling and heat management of the environment. The refrigeration unit includes a refrigeration compressor 110, a second heat exchanger 40, a refrigeration throttle valve 130 and an evaporator 150 connected in sequence. Specifically, the first link of the refrigeration cycle is the refrigeration compressor 110, in which the carbon dioxide gas at normal temperature and pressure is compressed. In this process, the pressure and temperature of the carbon dioxide gas are significantly increased, and the carbon dioxide gas is converted into a high-temperature and high-pressure state. This step is the power source of the entire refrigeration cycle, providing the necessary high-energy state gas for subsequent heat transfer and cooling. Then, the high-temperature and high-pressure carbon dioxide gas flows into the second heat exchanger 40. Here, the carbon dioxide releases heat and reduces temperature through heat exchange with the carbon dioxide sub-energy storage module. In this process, the carbon dioxide is converted from a gaseous state to a liquid state, becoming high-pressure and low-temperature carbon dioxide liquid. The key to the design of the second heat exchanger 40 is the high-efficiency heat exchange capability, which ensures that heat can be quickly and effectively removed from the carbon dioxide. The cooled and condensed carbon dioxide liquid then passes through the refrigeration throttle valve 130 for pressure reduction, so that the carbon dioxide liquid rapidly evaporates while the pressure is reduced, and the temperature is further reduced. The function of the refrigeration throttle valve 130 is to control the flow rate and pressure of the carbon dioxide, and to optimize the thermodynamic efficiency in the evaporation process. In the evaporator 150, the reduced pressure carbon dioxide evaporates by absorbing heat from the environment, and the cold effect generated in this process is used to cool the environment or provide services for other refrigeration needs. While the carbon dioxide gas absorbs heat, the environmental heat is effectively reduced to achieve the purpose of refrigeration. Finally, the evaporated carbon dioxide gas at normal temperature and pressure is circulated back to the refrigeration compressor 110 to start a new round of compression and circulation process. Through the above continuous refrigeration process, the refrigeration unit not only realizes efficient heat extraction and environmental cooling, but also maximizes energy utilization and system economy through closed-loop circulation design. In addition, the system ensures the stability and continuity of the refrigeration effect by precisely controlling the operation and interaction of each component, and is suitable for various application scenarios that require efficient refrigeration.

[0042] Further, the heat exchange process of the first coupling heat exchanger module 13 includes:

[0043] Based on the third heat exchanger 10, the low-temperature and low-pressure carbon dioxide gas transported from the low-pressure tank 70 is heated by the hot water transported from the hot water tank 50.

[0044] Based on the fourth heat exchanger 20, the low-pressure and medium-temperature carbon dioxide gas after energy release is cooled by the cold water transported from the cold water tank 60.

[0045] Optionally, the first coupled heat exchange module is a high-efficiency heat exchange system designed to regulate the temperature of carbon dioxide gas and recycle energy by optimizing thermal energy management. The core of this module's design lies in utilizing the temperature difference between hot water and cold water to heat and cool carbon dioxide gas through the third heat exchanger 10 and the fourth heat exchanger 20, thereby improving the energy efficiency and performance of the overall system. In the initial stage of the first coupled heat exchange module's operation, hot water is transported from the hot water tank 50 to the third heat exchanger 10. At this time, the third heat exchanger 10 acts as an intermediary for heat energy transfer, using the heat energy stored in the hot water to heat the low-temperature, low-pressure carbon dioxide gas transported from the low-pressure tank 70. In this process, the carbon dioxide gas absorbs the heat from the hot water, causing its temperature to rise and thus increasing the energy of the gas, providing the necessary conditions for subsequent energy conversion and utilization. At the same time, the fourth heat exchanger 20 takes on the task of cooling. In this phase, cold water transported from the cold water tank 60 is introduced into the fourth heat exchanger 20. When the low-pressure, medium-temperature carbon dioxide gas after energy release flows through the fourth heat exchanger 20, the cold water it encounters absorbs the heat stored in the gas, causing the temperature of the carbon dioxide to decrease. This cooling process not only helps to stabilize the temperature of the system, but also provides a low-temperature environment for the recycling of carbon dioxide. By heating carbon dioxide gas with hot water and cooling it with cold water, the temperature of the gas is efficiently regulated, and the efficiency of energy utilization is optimized. Through such a design, the first coupled heat exchange module not only realizes efficient recovery and reuse of energy, but also ensures the energy needs and environmental adaptability of the entire system in different working stages, thereby significantly improving the overall performance and economic benefits of the system.

[0046] Further, the heat exchange process of the second coupled heat exchange module 15 includes:

[0047] Based on the first heat exchanger 30, the carbon dioxide cooled and reduced in pressure by the heat supply throttle valve 120 cools and reduces the temperature of the high-temperature, high-pressure carbon dioxide gas from the energy storage compressor 90.

[0048] Based on the second heat exchanger 40, the high-pressure, high-temperature carbon dioxide gas pressurized and heated by the refrigeration compressor 110 heats and raises the temperature of the high-pressure, low-temperature carbon dioxide liquid from the high-pressure tank 80.

[0049] Further, the second coupled heat exchange module contains two core heat exchange processes, namely the cooling process based on the first heat exchanger 30 and the heating process based on the second heat exchanger 40, aiming to optimize the performance of the entire refrigeration and heating system. In the cooling process based on the first heat exchanger 30, the carbon dioxide gas that has been reduced in temperature and pressure through the heating throttling valve 120, which has already been reduced in temperature and pressure through decompression in the previous heating cycle. These low-temperature carbon dioxide gases then flow to the first heat exchanger 30 to cool the high-temperature and high-pressure carbon dioxide gas from the energy storage compressor 90. This high-temperature and high-pressure gas contains a large amount of heat energy, which is released and the temperature is reduced through heat exchange with low-temperature gas, optimizing energy management and reducing system heat loss. In the heating process based on the second heat exchanger 40, the high-pressure and high-temperature carbon dioxide gas generated by the refrigeration compressor 110 is used to heat the high-pressure and low-temperature carbon dioxide liquid stored in the high-pressure tank 80. The key to this step is to use the heat energy generated from the refrigeration unit to transfer it to the low-temperature carbon dioxide liquid through the second heat exchanger 40, so that the temperature rises and potentially re-gasifies, thereby preparing for the next energy release process. The effective combination of these two heat exchange processes ensures the optimal performance of the system in terms of heat energy management, so that heat energy can be maximally recovered and reused in the system, rather than simply lost or consumed. In this way, the second coupled heat exchange module not only improves energy use efficiency, but also reduces environmental impact in the energy conversion process. Overall, this module significantly improves the overall energy efficiency and reliability of the refrigeration and heating system through meticulous and precise temperature and pressure regulation.

[0050] Further, the turbine 160 is connected to the heating compressor 100 and the refrigeration compressor 110, respectively, to provide power supply for the heating compressor 100 and the refrigeration compressor 110.

[0051] Specifically, the turbomachinery 160 (i.e., turbine) is used to effectively connect and provide power support to the heat supply compressor 100 and the refrigeration compressor 110 in the system. The main function of the turbomachinery 160 is to convert the kinetic energy of high-pressure and high-temperature carbon dioxide gas into mechanical energy, and further convert it into electrical energy. In the system, the turbomachinery 160 is used to receive the energy-releasing gas from the energy storage subsystem, and the high-temperature and high-pressure carbon dioxide gas drives the turbine to rotate, generating mechanical energy which is converted into electrical power by the generator. The generated electrical power is not directly supplied to the external power grid, but is preferentially used to drive the heat supply compressor 100 and the refrigeration compressor 110 in the system. This internal power recycling significantly improves energy efficiency and reduces dependence on external power resources. By directly supporting the compressor with internally generated power, a high degree of energy self-sufficiency and operational efficiency is maintained. At the same time, by directly connecting the turbomachinery 160 with the heat supply and refrigeration compressors, the energy conversion process of the system is more compact and efficient. This design not only optimizes energy flow and reduces energy loss, but also adjusts the working efficiency of the compressor by precisely controlling the output of the turbomachinery, ensuring optimal energy efficiency ratio under different working conditions. By using the turbomachinery 160 as a power source connecting the heat supply and refrigeration compressors, a closed-loop energy management system is effectively realized, which not only improves energy use efficiency, but also enhances the environmental sustainability of the system.

[0052] Based on the technical solutions of the above embodiments, the refrigeration and heat supply cycle system coupled with carbon dioxide energy storage provided by the present application has the following technical effects:

[0053] 1. Improve system energy storage efficiency: By combining the carbon dioxide sub-energy storage module with the cold and heat storage module through the energy storage heat exchanger, the system cold and heat self-circulation is realized, avoiding additional cold and heat source supply, improving the system energy storage efficiency, and increasing the overall economy.

[0054] 2. Achieve true zero carbonization of energy storage, refrigeration and heat supply: By connecting external renewable resources such as wind and light, the carbon dioxide sub-energy storage module realizes the use of green electricity, and when the user end has heat and cold demand, the green electricity is released by the energy storage system as the power for refrigeration and heat supply.

[0055] 3. Reconstruct green energy supply mode: The working medium for refrigeration and heat supply is carbon dioxide, which abandons traditional fossil energy supply modes such as chlorofluorocarbon and coal-fired boilers.

[0056] 4. Green and stable operation of refrigeration and heat supply system: The power supply for refrigeration and heat supply system comes from the energy release process of the energy storage system, which avoids the instability of heat supply and refrigeration caused by direct external green electricity, and also avoids the cost increase caused by power grid electricity.

[0057] 5. Because carbon dioxide is used as the working fluid, the overall cooling and heating equipment is compact and can guarantee heating efficiency in extreme weather conditions compared to air source heat pumps. At the same time, the construction of each module is simple, with high integration, and can be applied rapidly on a large scale.

[0058] In summary, the cooling and heating cycle system coupled with carbon dioxide energy storage provided in this application not only improves the overall efficiency of the carbon dioxide energy storage system, but also achieves green, zero-carbon, stable, low-cost, and high-efficiency cooling and heating. It effectively addresses a series of problems existing in current cooling and heating storage technologies, realizes efficient energy storage and release, and reduces operating costs and improves the system's environmental compatibility through high-level system integration and optimization.

[0059] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application. In some cases, the actions or steps described in this application can be performed in a different order than that shown in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A refrigeration and heating cycle system coupled with carbon dioxide energy storage, characterized by, The system comprises: A carbon dioxide sub-energy storage module for performing an energy storage cycle based on the transformation of the critical state of carbon dioxide with carbon dioxide as the working medium; A cold and heat storage module for performing internal cold and heat self-circulation of a refrigeration and heating cycle system through heat exchange; A first coupling heat exchange module for coupling the cold and heat storage module to the carbon dioxide sub-energy storage module through an energy storage heat exchanger to perform internal heat exchange of the refrigeration and heating cycle system; A refrigeration and heating module for performing heat exchange between the carbon dioxide sub-energy storage module and external energy; A second coupling heat exchange module for coupling the refrigeration and heating module to the carbon dioxide sub-energy storage module through a refrigeration and heating heat exchanger to perform heat exchange between the refrigeration and heating cycle system and the outside; The refrigeration and heating heat exchanger comprises a first heat exchanger (30) and a second heat exchanger (40), and the energy storage heat exchanger comprises a third heat exchanger (10) and a fourth heat exchanger (20); The carbon dioxide sub-energy storage module comprises a low-pressure tank (70), the third heat exchanger (10), an energy storage compressor (90), the first heat exchanger (30), a high-pressure tank (80), the second heat exchanger (40), a turbine (160), and the fourth heat exchanger (20) connected in sequence; The cold and heat storage module comprises a hot water tank (50), the third heat exchanger (10), a cold water tank (60), and the fourth heat exchanger (20) connected in sequence; The refrigeration and heating module comprises a heating unit and a refrigeration unit, the heating unit comprises a heating compressor (100), a condenser (140), a heating throttle valve (120), and the first heat exchanger (30) connected in sequence, and the refrigeration unit comprises a refrigeration compressor (110), the second heat exchanger (40), a refrigeration throttle valve (130), and an evaporator (150) connected in sequence.

2. A carbon dioxide coupled energy storage refrigeration and heating cycle system as claimed in claim 1, wherein, The energy storage cycle process comprises: The low-temperature and low-pressure carbon dioxide gas released from the low-pressure tank (70) is heated through the third heat exchanger (10), the medium-temperature and low-pressure carbon dioxide gas after heating is pressurized by the energy storage compressor (90), and high-temperature and high-pressure carbon dioxide gas is obtained; The high-temperature and high-pressure carbon dioxide gas is cooled by the first heat exchanger (30), the high-pressure and low-temperature carbon dioxide liquid after cooling is stored in the high-pressure tank (80), and the stored energy is obtained; The high-pressure and low-temperature carbon dioxide liquid flowing out of the high-pressure tank (80) is heated and warmed by the second heat exchanger (40), and high-temperature and high-pressure carbon dioxide gas is obtained; The high-temperature and high-pressure carbon dioxide gas entering the turbine (160) drives the turbine to generate electricity, the stored energy is released, and low-pressure and medium-temperature carbon dioxide gas is obtained; The low-pressure and medium-temperature carbon dioxide gas is cooled by the fourth heat exchanger (20), low-temperature and low-pressure carbon dioxide gas is obtained, and is stored in the low-pressure tank (70).

3. A carbon dioxide coupled energy storage refrigeration and heating cycle system as set forth in Claim 2, wherein, The cold and heat self-circulation process comprises: The cold water flowing out of the cold water tank (60) is heated and warmed by the fourth heat exchanger (20), the heated water is stored in the hot water tank (50), and The hot water flowing out of the hot water tank (50) is cooled by the third heat exchanger (10) to obtain cooled water which is returned to the cold water tank (60).

4. A carbon dioxide coupled energy storage refrigeration and heating cycle system as set forth in Claim 3, wherein, The heat supply exchange process of heat exchange with external energy includes: The carbon dioxide gas at normal temperature and pressure is pressurized and heated by the heat supply compressor (100) to obtain high-temperature and high-pressure carbon dioxide gas; The high-temperature and high-pressure carbon dioxide gas is sent to the condenser (140) to release heat and heat up to obtain high-pressure and low-temperature carbon dioxide liquid, and the high-pressure and low-temperature carbon dioxide is depressurized and cooled by the heat supply throttle valve (120) and heated up by the first heat exchanger (30) to obtain carbon dioxide gas at normal temperature and pressure; The carbon dioxide gas at normal temperature and pressure is continuously sent to the heat supply compressor (100).

5. A carbon dioxide coupled energy storage refrigeration and heating cycle system as set forth in Claim 4 wherein, The refrigeration exchange process of heat exchange with external energy includes: The carbon dioxide gas at normal temperature and pressure is compressed by the refrigeration compressor (110) to obtain high-temperature and high-pressure carbon dioxide gas; The high-temperature and high-pressure carbon dioxide gas is cooled in the second heat exchanger (40) to obtain high-pressure and low-temperature carbon dioxide liquid; The high-pressure and low-temperature carbon dioxide is depressurized and cooled by the refrigeration throttle valve (130) and heated up by the evaporator (150) to obtain carbon dioxide gas at normal temperature and pressure, which is continuously sent to the refrigeration compressor (110).

6. A carbon dioxide coupled energy storage refrigeration and heating cycle system as set forth in Claim 3, wherein, The heat exchange process of the first coupled heat exchange module includes: Based on the third heat exchanger (10), the low-temperature and low-pressure carbon dioxide gas transported from the low-pressure tank (70) is heated by the hot water transported from the hot water tank (50); Based on the fourth heat exchanger (20), the low-pressure and medium-temperature carbon dioxide gas after energy release is cooled and cooled by the cold water transported from the cold water tank (60).

7. A carbon dioxide coupled energy storage refrigeration and heating cycle system as set forth in Claim 5, wherein, The heat exchange process of the second coupled heat exchange module includes: Based on the first heat exchanger (30), the high-temperature and high-pressure carbon dioxide gas from the energy storage compressor (90) is cooled and cooled by the carbon dioxide after depressurization and cooling by the heat supply throttle valve (120); Based on the second heat exchanger (40), the high-pressure and low-temperature carbon dioxide liquid from the high-pressure tank (80) is heated and heated by the high-pressure and high-temperature carbon dioxide gas pressurized and heated by the refrigeration compressor (110).

8. A carbon dioxide coupled energy storage refrigeration and heating cycle system as set forth in Claim 5, wherein, The turbine (160) is connected with the heat supply compressor (100) and the refrigeration compressor (110) respectively to provide power supply for the heat supply compressor (100) and the refrigeration compressor (110).

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