Building refrigeration system and method based on gravity driving and phase change energy storage

Abstract

The invention discloses a building refrigeration system and method based on gravity driving and phase change energy storage, and relates to the technical field of building environment and energy utilization. The system comprises a building body, an energy storage mechanism, at least one heat exchange part, a potential energy driving pipeline and a medium backflow mechanism, and the energy storage mechanism is arranged on a first mounting station and used for storing cold or heat in the power demand valley period; one end of the potential energy driving pipeline is connected with the energy storage mechanism, and the other end of the potential energy driving pipeline is connected with the heat exchange part, so that a fluid working medium for storing cold or heat in the energy storage mechanism is driven by gravitational potential energy to flow into the heat exchange part in the peak period of power demand; one end of the medium backflow mechanism is connected with the heat exchange parts, and the other end of the medium backflow mechanism is connected with the energy storage mechanism, receives the fluid working medium completing heat exchange in the power demand peak period and conveys the fluid working medium back to the energy storage mechanism in the power demand valley period. Zero-energy-consumption circulation of the secondary refrigerant is achieved through the height of the building, the phase change energy storage technology is combined, and the energy saving effect is remarkable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building environment and energy utilization, in particular to a building refrigeration system and method based on gravity driving and phase change energy storage. BACKGROUND

[0002] With the acceleration of economic development and urbanization process, the proportion of building energy consumption in total social energy consumption is rising, among which the air conditioning refrigeration energy consumption is particularly significant. During the summer peak period, air conditioning load becomes one of the key factors leading to the tension between supply and demand of power grid. To solve this problem, the cold storage air conditioning technology, such as ice storage technology, emerges as the times require. The technology stores ice during the off-peak period of night and melts ice to supply cooling during the peak period of day, effectively realizing "peak load shifting" and reducing the operation electricity cost of users.

[0003] However, the traditional ice storage central air conditioning system has a prominent energy consumption problem: in order to realize the delivery of cold energy, the system needs to be equipped with high-power chilled water circulating pumps, which run continuously all year round, with huge energy consumption, usually accounting for 15%-25% of the total system energy consumption. This not only increases the operation cost, but also to some extent weakens the energy saving benefits brought by "peak load shifting". Therefore, it is of great practical significance to develop a new type of refrigeration system which can not only take advantage of peak-valley electricity price, but also further reduce the delivery energy consumption. SUMMARY

[0004] The purpose of the present application is to provide a building refrigeration system and method based on gravity driving and phase change energy storage, to solve the problems existing in the prior art, to make full use of the height of the building itself, to realize the zero energy consumption circulation of the cold carrier, and to combine the phase change energy storage technology to achieve more significant energy saving effect.

[0005] To achieve the above purpose, the present application provides the following solutions: The application provides a building refrigeration system based on gravity driving and phase change energy storage, which comprises a building body, an energy storage mechanism, at least one heat exchange component, a potential energy driving pipeline and a medium return mechanism, the building body is provided with a first installation station and at least one second installation station, each second installation station is located in a target space of the building body, and the position of the first installation station is higher than that of the second installation station; the energy storage mechanism is arranged at the first installation station and is used for storing cold or heat during a power demand valley period; the heat exchange component is arranged at the second installation station and is used for adjusting the ambient temperature of the target space; one end of the potential energy driving pipeline is connected with the energy storage mechanism, and the other end is connected with the heat exchange component, so that the fluid working medium with stored cold or heat in the energy storage mechanism flows into the heat exchange component under the driving of the gravity potential energy of the fluid working medium during a power demand peak period; one end of the medium return mechanism is connected with each heat exchange component, and the other end is connected with the energy storage mechanism, and the medium return mechanism is used for receiving the fluid working medium after heat exchange during the power demand peak period and conveying the fluid working medium back to the energy storage mechanism during a power demand valley period.

[0006] Preferably, the energy storage mechanism is a cold storage mechanism used for storing cold, and the heat exchange component is a refrigeration terminal, and the fluid working medium is a cooling medium.

[0007] Preferably, the energy storage mechanism comprises a first box body, a phase change energy storage unit and an ice making host, the first box body is arranged at the first installation station, the ice making host is installed at the first installation station and located outside the first box body, the first box body is connected with the potential energy driving pipeline and the medium return mechanism, and the phase change energy storage unit is installed in the first box body and connected with the output end of the ice making host, and is used for receiving the cold generated by the ice making host during a power demand valley period and storing and releasing the cold through a phase change process.

[0008] Preferably, the phase change energy storage unit is encapsulated with a phase change material, and the phase change temperature of the phase change material is-5℃ to 10℃.

[0009] Preferably, the phase change energy storage unit is an ice ball or a plate type ice tank encapsulated with water.

[0010] Preferably, the heat exchange component is internally formed with a flow channel for the fluid working medium to flow, the inlet of the flow channel is connected with the potential energy driving pipeline, and the outlet is connected with the medium return mechanism, and when the cooling medium flows through the flow channel, the ambient temperature of the target space is reduced through heat exchange with the air in the target space.

[0011] Preferably, the potential energy driving pipeline comprises a main pipe, a plurality of branch pipes and a plurality of flow control valves, one end of the main pipe is connected to and communicates with the bottom of the first tank, the other end of the main pipe is connected to and communicates with each of the branch pipes, one end of each of the branch pipes away from the main pipe is connected to and communicates with the inlet of the flow channel of the corresponding heat exchange member, and one of the branch pipes is provided with one of the flow control valves to independently control the flow of the cold carrier in the corresponding branch pipe.

[0012] Preferably, the medium return mechanism comprises a second tank and a liquid supplementing pump, the second tank is installed at a position lower than the second installation station, one end of the second tank is connected to and communicates with each of the heat exchange members, the other end of the second tank is connected to and communicates with the liquid supplementing pump, and one end of the liquid supplementing pump away from the second tank is connected to and communicates with the first tank to transport the cold carrier temporarily stored in the second tank back to the first tank.

[0013] Preferably, the application further comprises a plurality of temperature sensors and a controller, the temperature sensors are arranged in the corresponding target spaces to collect the ambient temperature of the target spaces in real time, the flow control valves are electromagnetic valves, and each of the temperature sensors and the electromagnetic valves is electrically connected to the controller to enable the controller to automatically adjust the opening degree of the electromagnetic valve on the corresponding branch pipe according to the ambient temperature data collected by the temperature sensor.

[0014] The application further provides a use method of the building refrigeration system based on gravity driving and phase change energy storage as described in any one of the above, comprising the following steps: S1: during the power demand low valley period, the energy storage mechanism is started to run, so that the fluid working substance completes the cold or heat storage process in the energy storage mechanism; at this time, the medium return mechanism transports the fluid working substance which has completed heat exchange and is collected during the power demand peak period back to the energy storage mechanism to supplement the fluid working substance in the energy storage mechanism; S2: when entering the power demand peak period, the energy storage mechanism stops active refrigeration or heating, the fluid working substance which has stored cold or heat in the energy storage mechanism flows into the heat exchange member arranged in the target space under the action of the gravity potential energy; the fluid working substance exchanges heat with the ambient air of the target space in the heat exchange member, absorbs the heat in the target space or releases cold, so as to adjust the ambient temperature of the target space; S3: the fluid working substance which has completed heat exchange is raised or lowered in temperature, then flows out of the heat exchange member and enters the medium return mechanism, and the medium return mechanism temporarily stores the fluid working substance; S4: when entering the power demand low valley period again, the step S1 is repeatedly performed, so that the medium return mechanism transports the temporarily stored fluid working substance back to the energy storage mechanism to start a new round of energy storage and refrigeration / heating cycle.

[0015] The present invention achieves the following technical effects compared to the prior art: This invention provides a building cooling system and method based on gravity-driven and phase-change energy storage. It fully utilizes the building's spatial layout, setting up energy storage mechanisms and heat exchange components at varying installation positions. Potential energy is used to drive pipelines and a medium return mechanism to circulate the working fluid. By cleverly leveraging gravity, no additional power equipment is needed to propel the fluid between the energy storage mechanism and the heat exchange components, significantly reducing system energy consumption. Furthermore, this time-sharing method of storing and releasing cold or heat effectively utilizes resources during off-peak electricity hours, achieving optimized energy utilization. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the structure of a building refrigeration system based on gravity drive and phase change energy storage provided by the present invention; In the diagram: 1. First housing; 2. Phase change energy storage unit; 3. Second housing; 4. Heat exchanger; 5. Main pipe; 6. Branch pipe; 7. Ice maker; 8. Liquid replenishment pump; 9. Building body; 10. Flow control valve. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] The purpose of this invention is to provide a building refrigeration system and method based on gravity drive and phase change energy storage to solve the problems existing in the prior art, make full use of the building's height, achieve zero-energy cycle of refrigerant, and achieve a more significant energy-saving effect by combining phase change energy storage technology.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Example 1 This embodiment provides a building cooling system based on gravity drive and phase change energy storage, as shown in Figure 1. It includes: a building body 9, an energy storage mechanism, at least one heat exchanger 4, a potential energy drive pipeline, and a medium reflux mechanism. The building body 9 has a first installation position and at least one second installation position. Each second installation position is located within the target space of the building body 9, and the position of the first installation position is higher than the position of the second installation position. The energy storage mechanism is located at the first installation position for storing cold or heat energy during periods of low electricity demand. The heat exchanger 4 is located at the second installation position to regulate the ambient temperature of the target space. One end of the potential energy drive pipeline is connected to the energy storage mechanism, and the other end is connected to the heat exchanger 4, so that the fluid working medium storing cold or heat energy in the energy storage mechanism can be cooled during periods of high electricity demand. During peak hours, the fluid flows into the heat exchanger 4 driven by its gravitational potential energy. One end of the medium return mechanism is connected to each heat exchanger 4, and the other end is connected to the energy storage mechanism. The medium return mechanism is used to receive the fluid working medium after heat exchange during peak electricity demand periods and to transport the fluid working medium back to the energy storage mechanism during off-peak electricity demand periods. This structural design makes full use of the spatial layout of the building body 9, setting up the energy storage mechanism and heat exchanger 4 at different installation positions, and using potential energy to drive the pipeline and medium return mechanism to achieve the circulation of the fluid working medium. It cleverly uses gravity to drive the fluid working medium without the need for additional power equipment to push the fluid working medium to flow between the energy storage mechanism and the heat exchanger 4, which greatly reduces the system energy consumption. At the same time, this time-sharing storage and release of cold or heat energy can effectively utilize resources during off-peak electricity periods and achieve optimized energy utilization.

[0022] In a preferred embodiment, the energy storage mechanism is a cold storage mechanism used to store cold energy, the heat exchange component 4 is a refrigeration terminal, and the fluid working medium is a refrigerant. This clarifies the specific attributes of the main components of the system in terms of refrigeration function, allowing the system to focus on the refrigeration field. The cold storage mechanism is specifically used to store cold energy, the refrigeration terminal is responsible for transferring the cold energy to the target space to achieve refrigeration, and the refrigerant serves as the medium for cold energy transfer. The three work together to ensure the effective realization of the building's refrigeration function.

[0023] In a preferred embodiment, the energy storage mechanism includes a first housing 1, a phase change energy storage unit 2, and an ice maker 7. The first housing 1 is located at a first installation position, and the ice maker 7 is installed at the first installation position and located outside the first housing 1. The first housing 1 is connected to a potential energy drive pipeline and a medium return mechanism. The phase change energy storage unit 2 is installed inside the first housing 1 and connected to the output end of the ice maker 7. It is used to receive the cooling energy generated by the ice maker 7 during periods of low electricity demand and store and release the cooling energy through a phase change process. The detailed design of the energy storage mechanism makes the storage and release of cooling energy more efficient and orderly. The first housing 1 provides physical space for the entire energy storage mechanism, accommodates the phase change energy storage unit 2, and connects to the pipeline to realize the flow of the working fluid. The ice maker 7 operates during periods of low electricity demand, cooling and changing the phase of the material in the phase change energy storage unit 2 to store a large amount of cooling energy. The phase change energy storage unit 2 utilizes the phase change characteristics of the material to release cooling energy during peak electricity demand, providing a stable cold source supply for the refrigeration system and realizing "peak shaving and valley filling" of electricity.

[0024] In a preferred embodiment, the phase change energy storage unit 2 encapsulates a phase change material with a phase change temperature ranging from -5°C to 10°C. Limiting the phase change temperature of the phase change material to this range allows the phase change energy storage unit 2 to store and release cooling capacity within a temperature range suitable for building cooling. This temperature range ensures effective storage of cooling capacity during off-peak electricity periods and provides a suitable refrigerant temperature for the cooling terminals during peak electricity demand, ensuring cooling performance while optimizing the system's adaptability to building cooling needs.

[0025] In a preferred embodiment, the phase change energy storage unit 2 is an ice ball or plate-type ice tank encapsulated with water. The ice ball or plate-type ice tank, as a specific form of the phase change energy storage unit 2, has good encapsulation properties and a large cold storage surface area. Water, as a phase change material, is widely available, inexpensive, and has good cold storage performance. This design not only facilitates arrangement and installation within the first housing 1 but also improves the cold storage efficiency of the phase change energy storage unit 2, enhancing the system's economy and practicality.

[0026] In a preferred embodiment, the heat exchanger 4 has a flow channel for the fluid working medium. The inlet of the flow channel is connected to the potential energy drive pipeline, and the outlet is connected to the medium return mechanism. When the refrigerant flows through the flow channel, it exchanges heat with the air in the target space, thereby reducing the ambient temperature of the target space. The design of the flow channel inside the heat exchanger 4 ensures that the refrigerant and the air in the target space can fully exchange heat. During the flow of the refrigerant in the flow channel, it efficiently transfers the cooling capacity it carries to the surrounding air, thereby achieving the purpose of reducing the ambient temperature of the target space and ensuring the cooling effect of the refrigeration system.

[0027] In a preferred embodiment, the potential energy drive pipeline includes a main pipe 5, multiple branch pipes 6, and multiple flow control valves 10. One end of the main pipe 5 is connected to and communicates with the bottom of the first housing 1, and the other end is connected to and communicates with each branch pipe 6. The end of each branch pipe 6 away from the main pipe 5 is connected to and communicates with the inlet of the flow channel of the corresponding heat exchange component 4. Each branch pipe 6 is equipped with a flow control valve 10 to independently control the flow rate of the refrigerant in the corresponding branch pipe 6. This structural design of the potential energy drive pipeline allows the refrigerant to be evenly distributed from the bottom of the first housing 1 through the main pipe 5 to each branch pipe 6 and flow to the corresponding heat exchange component 4. The flow control valves 10 allow for independent adjustment of the refrigerant flow rate in each branch pipe 6, enabling flexible adjustment of the refrigerant flow rate according to the cooling needs of different target spaces, achieving precise cooling, improving the cooling efficiency and energy utilization efficiency of the system, and enhancing the adaptability of the system.

[0028] In a preferred embodiment, the medium return mechanism includes a second housing 3 and a replenishment pump 8. The second housing 3 is installed below the second installation position, with one end connected to and communicating with each heat exchanger 4, and the other end connected to the replenishment pump 8. The end of the replenishment pump 8 away from the second housing 3 is connected to and communicating with the first housing 1 to transport the refrigerant temporarily stored in the second housing 3 back to the first housing 1. The second housing 3 is used to collect the refrigerant returning from the heat exchangers 4, and its position below the second installation position facilitates the natural flow of the refrigerant by gravity. The replenishment pump 8 transports the refrigerant in the second housing 3 back to the first housing 1 during periods of low power consumption, preparing for the next energy storage and refrigeration cycle. This design ensures the recycling of the refrigerant, ensures the continuous and stable operation of the system, and improves the system's reliability and energy recycling rate.

[0029] In a preferred embodiment, the system further includes multiple temperature sensors and a controller. The temperature sensors are positioned within the corresponding target space to collect the ambient temperature in real time. The flow control valve 10 is a solenoid valve. Each temperature sensor and solenoid valve is electrically connected to the controller, enabling the controller to automatically adjust the opening of the solenoid valve on the corresponding branch pipe 6 based on the ambient temperature data collected by the temperature sensors. The temperature sensors monitor the ambient temperature of the target space in real time and feed the data back to the controller. The controller automatically adjusts the opening of the solenoid valve based on this data, thereby precisely controlling the refrigerant flow rate in each branch pipe 6. This automated adjustment method allows the refrigeration system to adjust the cooling capacity in real time according to the actual temperature requirements of different target spaces, further improving the accuracy of refrigeration and energy efficiency, while also enhancing user comfort and making the system more intelligent and user-friendly.

[0030] In a preferred embodiment, the first container 1 is a structural water tank on the roof of the building 9 or a specially constructed storage tank.

[0031] In a preferred embodiment of this invention, the working fluid is an ethylene glycol solution.

[0032] The present invention also provides a method for using a building cooling system based on gravity drive and phase change energy storage as described in any of the above claims, comprising the following steps: 1. System Installation and Preparation The first installation station and the second installation station of the building body 9 are determined. The first installation station is located at a high position such as the top of the building, and the second installation stations are distributed in the target space of each floor of the building, ensuring that the position of the first installation station is higher than that of the second installation station.

[0033] Install the first housing 1 at the first installation station, and install the ice maker 7 on the outside of the first housing 1. Install the phase change energy storage unit 2 inside the first housing 1, and connect the phase change energy storage unit 2 to the output terminal of the ice maker 7. For example, if the phase change energy storage unit 2 is an ice ball encapsulating water, the position of the ice ball inside the first housing 1 needs to be properly arranged to ensure smooth cold energy transfer with the ice maker 7. At the same time, connect the first housing 1 to the potential energy drive pipeline and the medium return mechanism.

[0034] Install heat exchange components 4 (refrigeration terminals) at each of the second installation stations, ensuring that the inlet of the internal flow channel of the heat exchange component 4 is connected to the potential energy drive pipeline, and the outlet is connected to the medium return mechanism.

[0035] One end of the main pipe 5 of the potential energy drive pipeline is connected to the bottom of the first housing 1 and in communication, and the other end is connected to each branch pipe 6 and in communication. The other end of each branch pipe 6 is connected to the inlet of the corresponding heat exchange component 4. A flow control valve 10 is installed on each branch pipe 6.

[0036] Install the second housing 3 at a position lower than the second installation station. Connect one end of the second housing 3 to each heat exchange component 4 and communicate with it. Connect the other end of the second housing 3 to the replenishment pump 8. Connect the other end of the replenishment pump 8 to the first housing 1 and communicate with it.

[0037] Temperature sensors are installed in each target space, and the temperature sensors and the solenoid valves used as flow control valves 10 are electrically connected to the controller.

[0038] 2. Off-peak electricity demand periods (energy storage phase) Cold energy storage: The ice maker 7 is activated, generating cold energy which is then transferred to the phase change energy storage unit 2 inside the first housing 1. For example, if the phase change energy storage unit 2 is an ice ball, the water inside the ice ball gradually freezes under the action of the ice maker 7, storing a large amount of cold energy through the phase change process of water. This process utilizes off-peak electricity prices to reduce energy storage costs.

[0039] Refrigerant circulation: Start the replenishment pump 8, which transports the refrigerant temporarily stored in the second tank 3 back to the first tank 1, so that the refrigerant can fully contact the phase change energy storage unit 2 with the stored cold energy in the first tank 1, absorb the cold energy, and complete the preparation for cold energy storage of the refrigerant.

[0040] 3. Peak electricity demand periods (cooling phase) Cold energy delivery: Turn off the replenishment pump 8 and the ice maker 7. The refrigerant that has absorbed the cold energy in the first housing 1 flows from the bottom of the first housing 1 through the main pipe 5 into each branch pipe 6 due to the height difference between the first and second installation positions and driven by gravitational potential energy. The flow control valve 10 (solenoid valve) on each branch pipe 6 adjusts the refrigerant flow according to the controller command, so that the refrigerant flows into the corresponding heat exchange component 4 (refrigeration terminal).

[0041] Cooling operation: The refrigerant enters the internal flow channel of the heat exchanger 4 and exchanges heat with the air in the target space. For example, if the heat exchanger 4 is a fan coil unit, the fan blows hot indoor air through the coil, and the refrigerant absorbs the heat from the air, lowering the air temperature, thereby achieving cooling of the target space.

[0042] Refrigerant reflux: After heat exchange is completed, the refrigerant with increased temperature flows out from the outlet of the heat exchange component 4 and flows into the second box 3 for temporary storage by gravity.

[0043] 4. Automatic temperature control During the cooling phase, the temperature sensor collects the ambient temperature of the target space in real time and transmits the temperature data to the controller. Based on the received temperature data, the controller automatically adjusts the opening of the solenoid valve on the corresponding branch pipe 6. If the temperature of the target space is high, the controller increases the opening of the solenoid valve, allowing more refrigerant to flow into the heat exchange component 4 corresponding to the target space, thus enhancing the cooling effect; if the temperature is low, the controller decreases the opening of the solenoid valve to reduce the refrigerant flow and avoid over-cooling, thereby achieving precise automatic adjustment of the target space temperature.

[0044] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A building cooling system based on gravity drive and phase change energy storage, characterized in that: include: The building body has a first installation station and at least one second installation station, each of the second installation stations being located within the target space of the building body, and the position of the first installation station being higher than the position of the second installation station. An energy storage mechanism, which is installed at the first installation station, is used to store cold or heat during periods of low electricity demand. At least one heat exchanger is provided at the second installation station to regulate the ambient temperature of the target space; A potential energy driving pipeline, one end of which is connected to the energy storage mechanism and the other end of which is connected to the heat exchange component, so that the fluid working medium that has stored cold or heat in the energy storage mechanism flows into the heat exchange component under the drive of its gravitational potential energy during peak power demand periods. as well as The medium return mechanism has one end connected to each of the heat exchange components and the other end connected to the energy storage mechanism. The medium return mechanism is used to receive the fluid working medium after heat exchange during peak power demand periods and to transport the fluid working medium back to the energy storage mechanism during off-peak power demand periods.

2. The building cooling system based on gravity drive and phase change energy storage according to claim 1, characterized in that: The energy storage mechanism is a cold storage mechanism used to store cold energy, the heat exchange component is a refrigeration terminal, and the fluid working medium is a refrigerant.

3. The building cooling system based on gravity drive and phase change energy storage according to claim 2, characterized in that: The energy storage mechanism includes a first housing, a phase change energy storage unit, and an ice maker. The first housing is disposed at the first installation position, and the ice maker is installed at the first installation position and located outside the first housing. The first housing is connected to the potential energy drive pipeline and the medium return mechanism. The phase change energy storage unit is installed inside the first housing and connected to the output end of the ice maker. It is used to receive the cold energy generated by the ice maker during periods of low electricity demand and store and release the cold energy through a phase change process.

4. The building cooling system based on gravity drive and phase change energy storage according to claim 3, characterized in that: The phase change energy storage unit is encapsulated with a phase change material, and the phase change temperature of the phase change material is -5℃ to 10℃.

5. The building cooling system based on gravity drive and phase change energy storage according to claim 4, characterized in that: The phase change energy storage unit is an ice ball or plate ice tank encapsulated with water.

6. The building cooling system based on gravity drive and phase change energy storage according to claim 2, characterized in that: The heat exchanger has a flow channel inside for the flow of the working fluid. The inlet of the flow channel is connected to the potential energy drive pipeline, and the outlet is connected to the medium return mechanism. When the refrigerant flows through the flow channel, it exchanges heat with the air in the target space to reduce the ambient temperature of the target space.

7. The building cooling system based on gravity drive and phase change energy storage according to claim 6, characterized in that: The potential energy driving pipeline includes a main pipe, multiple branch pipes, and multiple flow control valves. One end of the main pipe is connected to and communicates with the bottom of the first housing, and the other end is connected to and communicates with each of the branch pipes. The end of each branch pipe away from the main pipe is connected to and communicates with the inlet of the flow channel of the corresponding heat exchange component. Each branch pipe is equipped with a flow control valve to independently control the flow rate of the refrigerant in the corresponding branch pipe.

8. The building cooling system based on gravity drive and phase change energy storage according to claim 1, characterized in that: The medium return mechanism includes a second housing and a replenishment pump. The second housing is installed at a position lower than the second installation station. One end of the second housing is connected and communicates with each of the heat exchange components, and the other end is connected and communicates with the replenishment pump. The end of the replenishment pump away from the second housing is connected and communicates with the first housing to transport the refrigerant temporarily stored in the second housing back to the first housing.

9. The building cooling system based on gravity drive and phase change energy storage according to claim 1, characterized in that: It also includes multiple temperature sensors and a controller. The temperature sensors are set in the corresponding target space to collect the ambient temperature of the target space in real time. The flow control valve is a solenoid valve. Each of the temperature sensors and the solenoid valve is electrically connected to the controller so that the controller can automatically adjust the opening degree of the solenoid valve on the corresponding branch pipe according to the ambient temperature data collected by the temperature sensors.

10. A method of using a building cooling system based on gravity drive and phase change energy storage as described in any one of claims 1 to 9, characterized in that: Includes the following steps: S1: During periods of low electricity demand, the energy storage mechanism is activated, allowing the working fluid to complete the storage process of cold or heat within the energy storage mechanism. At this time, the medium return mechanism transports the working fluid collected during periods of high electricity demand, after heat exchange, back to the energy storage mechanism to replenish the working fluid within the energy storage mechanism. S2: When the peak electricity demand period arrives, the energy storage device stops actively cooling or heating. Under the action of gravitational potential energy, the fluid working medium that has stored cold or heat in the energy storage device flows naturally into the heat exchanger set in the target space through the potential energy driving pipeline. The fluid working medium exchanges heat with the ambient air in the target space in the heat exchanger, absorbing heat or releasing cold in the target space, thereby regulating the ambient temperature of the target space. S3: After heat exchange, the temperature of the working fluid increases or decreases, and then flows out of the heat exchange component and enters the medium return mechanism, which temporarily stores these working fluids. S4: When the power demand is low again, repeat step S1 to allow the medium return mechanism to transport the temporarily stored fluid back to the energy storage mechanism and start a new round of energy storage and cooling / heating cycle.

Images