Buried multi-mode driving energy storage system

Abstract

The invention discloses a buried multi-mode driving energy storage system which comprises a buried energy storage system, a liquid level regulation and control system and a heat exchanger device. The buried energy storage system comprises an energy storage device, a buried energy storage cavity and an efficient heat preservation layer. The liquid level and liquid quantity regulation and control system comprises three bypass pipelines, four electromagnetic valves, a variable-frequency liquid pump and a liquid storage container; temperature sensors are respectively arranged at the two working medium interfaces and in the middle of the two working medium interfaces; all the temperature sensors, the third temperature sensor of the heat exchanger, the five electromagnetic valves and the variable-frequency liquid pump are connected with a controller through signal cables. According to the buried multi-mode driving energy storage system, a passive cold storage mode and an active and passive dual-mode composite heat storage mode are adopted, the operation of the system is very reliable, the response speed is very high, and the system is very stable.

Description

Technical Field

[0001] The present invention relates to the technical field of energy management, and in particular to an underground multi-mode drive energy storage system. Background Art

[0002] In modern society, with the continuous increase in energy demand and the increasing attention to environmental protection, energy storage technology has become an important research direction in the fields of energy management technology and power electronics technology. Energy storage technology mainly stores energy through various physical or chemical methods and releases it when needed, so as to achieve optimal configuration and utilization of energy. Among them, the buried energy storage system is an important energy storage method. By burying the energy storage device underground, it can effectively utilize geothermal resources and improve energy utilization efficiency. Existing buried energy storage systems usually adopt a single heat storage or cold storage method, such as passive cold storage or active heat storage. Passive cold storage converts geothermal energy into cold energy through natural convection and radiation, while passive heat storage converts geothermal energy into heat energy through heat exchangers. However, these single heat storage or cold storage methods have some problems, such as low energy storage efficiency and slow response speed. There are still some problems in the actual application of existing buried energy storage systems. First of all, the existing buried energy storage system can usually only adopt a single heat storage or cold storage method, which leads to low energy storage efficiency of the system and cannot meet the growing energy demand. Secondly, the existing underground energy storage system has a slow response speed and cannot quickly respond to changes in energy demand, which limits its application in the fields of energy management technology and power electronics technology. Finally, the existing underground energy storage system has low operating reliability and is easily affected by the external environment, which affects the stability and service life of the system. Summary of the invention

[0003] The purpose of the present invention is to provide an underground multi-mode driven energy storage system. Compared with the prior art, this technical solution mainly solves the following technical problems: It solves the problem that the existing underground energy storage system can only adopt a single heat storage or cold storage method. By adopting passive cold storage and active and passive dual-mode composite heat storage, the energy storage efficiency of the system is improved, and the growing energy demand can be better met; It solves the problem of slow response speed of the existing underground energy storage system. By adopting equipment such as variable frequency liquid pumps and solenoid valves, precise control of the liquid in the system is achieved, thereby speeding up the response speed of the system and being able to quickly respond to changes in energy demand; It solves the problem of low operating reliability of the existing underground energy storage system. By adopting equipment such as high-efficiency insulation layers and liquid level control systems, the operating reliability of the system is improved, the impact on the external environment is reduced, and the stability and service life of the system are improved. In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: an underground multi-mode driven energy storage system, including an underground energy storage system, a liquid level control system and a heat exchanger device;

[0004] The buried energy storage system comprises an energy storage device, a buried energy storage cavity and a high-efficiency thermal insulation layer, wherein the buried energy storage cavity is arranged in the body of the energy storage device, the high-efficiency thermal insulation layer covers the surface of the energy storage device and the upper part of the buried energy storage cavity, a No. 1 liquid level sensor is installed on the upper part of the buried energy storage cavity, and a No. 2 liquid level sensor is installed on the lower part of the buried energy storage cavity, a No. 1 liquid interface of the heat exchanger device is connected to one end of a No. 1 liquid pipe, and the other end of the No. 1 liquid pipe passes through the high-efficiency thermal insulation layer and enters the interior of the buried energy storage cavity, and the end face of the pipe mouth is higher than the upper part of the buried energy storage cavity and higher than the No. 1 liquid level sensor, a No. 2 liquid interface of the heat exchanger device is connected to one end of a No. 2 liquid pipe, and the other end of the No. 2 liquid pipe passes through the thermal insulation layer and enters the interior of the buried energy storage cavity, and the lower end of the pipe mouth is immersed in the phase change liquid and is located below the No. 2 liquid level sensor, and a No. 1 solenoid valve is installed on the No. 2 liquid pipe;

[0005] The liquid level control system includes the liquid level and liquid quantity control system including three bypass pipelines, four solenoid valves, a variable frequency liquid pump and a liquid storage container; one port of the No. 1 bypass pipeline is connected to the No. 2 liquid pipe and the No. 2 liquid interface, and the other port of the No. 1 bypass pipeline is connected to the upper port of the liquid storage container, on which the No. 2 solenoid valve and the No. 4 solenoid valve are installed in sequence; one port of the No. 2 bypass pipeline is connected to the No. 2 liquid pipe, the No. 1 solenoid valve is located on the No. 2 liquid pipe between the No. 1 bypass pipeline and the No. 2 bypass pipeline, and the other port of the No. 2 bypass pipeline is connected to the lower port of the liquid storage container, and the No. 3 solenoid valve and the No. 5 solenoid valve are installed on the second bypass pipeline, one port of the No. 3 bypass pipeline is connected to the No. 1 bypass pipeline between the No. 2 solenoid valve and the No. 4 solenoid valve, and the other port of the No. 3 bypass pipeline is connected to the No. 2 bypass pipeline between the No. 3 solenoid valve and the No. 5 solenoid valve, and the variable frequency liquid pump is installed on the No. 3 bypass pipeline;

[0006] The first and second liquid interfaces are respectively provided with a first temperature sensor of the heat exchanger device and a second temperature sensor of the heat exchanger device, and a third temperature sensor of the heat exchanger device is installed in the middle;

[0007] The heat exchanger's No. 1 to No. 3 temperature sensors, No. 1 and No. 2 liquid level sensors, No. 1 to No. 5 solenoid valves and variable frequency liquid pump are all connected to the controller via signal cables.

[0008] Preferably, the No. 1 liquid pipe is provided with a liquid filling port.

[0009] Preferably, the pipe opening at the other end of the No. 2 liquid pipe is connected to the filter.

[0010] The technical effects and advantages of the present invention are as follows: 1. Improved energy storage efficiency: The underground multi-mode drive energy storage system of the present invention adopts a passive cold storage and active-passive dual-mode composite heat storage method. This composite heat storage method can make full use of geothermal resources, improve energy storage efficiency, and better meet the growing energy demand;

[0011] 2. Accelerate response speed: The underground multi-mode drive energy storage system of the present invention adopts a passive cold storage and active-passive dual-mode composite heat storage method. This composite heat storage method can quickly respond to changes in energy demand, improve the response speed of the system, and make it have a wider application prospect in the fields of energy management technology and power electronics technology;

[0012] 3. Improve operational reliability: The underground multi-mode drive energy storage system of the present invention adopts a passive cold storage and active-passive dual-mode composite heat storage method. This composite heat storage method can effectively reduce the impact of the external environment on the system, improve the operational reliability of the system, and extend the service life of the system;

[0013] 4. Optimize liquid level control: The underground multi-mode drive energy storage system of the present invention includes a liquid level and liquid volume control system. Through the cooperation of three bypass pipes, four solenoid valves, a variable frequency liquid pump and a liquid storage container, the liquid level can be accurately controlled to ensure the normal operation of the system and improve the stability and safety of the system;

[0014] 5. Precise temperature control: The underground multi-mode drive energy storage system of the present invention is provided with temperature sensors at the two working fluid interfaces and in the middle. These temperature sensors are connected to the controller and can monitor the temperature of the system in real time to ensure the normal operation of the system and improve the stability and safety of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the cold storage season operation of the present invention;

[0016] Figure 2 It is a schematic diagram of the heat storage season operation of the present invention.

[0017] In the figure, 1. high-efficiency insulation layer; 2. energy storage body; 3. heat exchanger device; 4. buried energy storage chamber; 5. No. 1 solenoid valve; 6. No. 1 liquid level sensor; 7. No. 1 liquid pipe; 8. No. 2 liquid pipe; 9. filter; 10. No. 2 liquid level sensor; 11. No. 2 solenoid valve; 12. No. 3 solenoid valve; 13. variable frequency liquid pump; 14. controller; 15. No. 4 solenoid valve; 16. No. 5 solenoid valve; 17. liquid storage container; 18. heat exchanger inlet; 19. heat exchanger device outlet; 20. liquid filling port; 21. liquid; 22. No. 1 bypass pipe; 23. No. 2 bypass pipe; 24. No. 3 bypass pipe; 25. No. 1 temperature sensor of heat exchanger device; 26. No. 2 temperature sensor of heat exchanger device; 27. No. 3 temperature sensor of heat exchanger device. DETAILED DESCRIPTION

[0018] In order to make the technical means for realizing the present invention, the creative features, the objectives and effects to be achieved easy to understand, the present invention is further explained below in conjunction with specific diagrams. In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, an integral connection or a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two components.

[0019] Example

[0020] like Figure 1 and Figure 2The buried multi-mode drive energy storage system shown includes an buried energy storage system, a liquid level control system, a heat exchanger device 3, a No. 1 liquid pipe 7, a No. 2 liquid pipe 8 and other connecting pipelines. The underground energy storage system includes an energy storage body 2, a high-efficiency thermal insulation layer 1 and a buried energy storage cavity 4. A borehole is opened on the energy storage body 2, and the buried energy storage cavity 4 is installed in the above-mentioned borehole. The high-efficiency thermal insulation layer 1 covers the upper surface of the energy storage body 2 and the buried energy storage cavity 4. A No. 1 liquid level sensor 8 is installed on the upper part of the buried energy storage cavity 4, and a No. 2 liquid level sensor 10 is installed on the lower part. A liquid filling port 20 is reserved on the No. 1 liquid pipe 7. One end of the No. 1 liquid pipe 7 is connected to the No. 1 liquid interface of the heat exchanger device 3, and the other end passes through the high-efficiency thermal insulation layer 1 to enter the buried energy storage cavity 4, and the pipe mouth is higher than the upper part of the buried energy storage cavity and higher than the No. 1 liquid level sensor 6. One end of the No. 2 liquid pipe 8 is connected to the No. 2 liquid interface of the heat exchanger device 3, and the other end passes through the high-efficiency insulation layer 1 and enters the buried energy storage chamber 4 to connect with the filter 9, and the pipe mouth is lower than the lower part of the buried energy storage chamber and lower than the No. 2 liquid level sensor 10. The heat exchanger device 3 has a heat exchanger device inlet 18 and a heat exchanger device outlet 19. The No. 1 solenoid valve 5 is installed on the No. 2 liquid pipe 8, and a liquid volume control system is installed on the bypass pipeline of the No. 2 liquid pipe 8. The liquid volume control system includes a No. 1 bypass pipeline 22, a No. 2 bypass pipeline 23, a No. 3 bypass pipeline 24, a No. 2 solenoid valve 11, a No. 3 solenoid valve 12, a No. 4 solenoid valve 15, a No. 5 solenoid valve 16, a variable frequency liquid pump 13 and a liquid storage container 17; the liquid storage container 17 is filled with a phase change liquid 21. One port of the No. 1 bypass pipeline 22 is connected to the No. 2 liquid pipe 8 and the No. 2 liquid interface, and the other port of the No. 1 bypass pipeline 22 is connected to the upper port of the liquid storage container 17. The No. 1 bypass pipeline 22 is installed with the No. 2 solenoid valve 11 and the No. 4 solenoid valve 15 at one time; one port of the No. 2 bypass pipeline 23 is connected to the No. 2 liquid pipe 8, the No. 1 solenoid valve 5 is installed on the No. 2 liquid pipe 8, and the other port of the No. 2 bypass pipeline 23 is connected to the lower port of the liquid storage container 17. The No. 3 solenoid valve 12 and the No. 5 solenoid valve 16 are installed on the No. 2 bypass pipeline 23 in sequence, and one port of the No. 3 bypass pipeline 24 is connected to the No. 1 bypass pipeline 22 between the No. 2 solenoid valve 11 and the No. 4 solenoid valve 15, and the other port of the No. 3 bypass pipeline 24 is connected to the No. 2 bypass pipeline 23, and the variable frequency liquid pump 13 is installed on the No. 3 bypass pipeline 24;

[0021] The first and second liquid interface positions are respectively installed with the first temperature sensor 25 of the heat exchanger device, the third temperature sensor 27 of the heat exchanger device and the second temperature sensor 26 of the heat exchanger device;

[0022] The above mentioned electrical components are all connected to the controller via signal cables 17;

[0023] The underground multi-mode drive energy storage system of the present invention is divided into three modes: cold storage mode, heat storage mode and liquid volume control during operation.

[0024] Cold storage mode: The controller 14 sends a cold storage control command to the system, only opening Figure 1 The phase-change liquid in the liquid storage container 17 is gradually injected into the buried energy storage chamber 4 under the action of gravity, and the liquid level sensor monitors the liquid level change in the buried energy storage chamber 4 in real time. When the liquid level of the phase-change liquid 21 reaches the position of the No. 1 liquid level sensor 6, the controller 14 immediately issues a command to close the No. 2 to No. 5 solenoid valves and open the No. 1 solenoid valve 5. The above process is the initial liquid volume preparation process and control method in the cold storage season.

[0025] After the initial liquid volume is prepared in the cold storage season, the phase change liquid 21 in the buried energy storage chamber 4 absorbs heat and changes phase to evaporate into steam under the heating of the heat in the energy storage body 2. The generated steam gradually accumulates in the space above the No. 1 liquid level sensor 6, and continuously enters the heat exchanger device 3 through the No. 1 liquid pipe 7 under the action of phase change. The steam entering the heat exchanger device 3 undergoes an exothermic phase change and condenses into liquid under the cooling action of the cold liquid fluid at the inlet 18 of the heat exchanger device, and flows back to the buried energy storage chamber 4 through the No. 2 liquid pipe 8 under the action of gravity. In this process, the temperature sensor of the heat exchanger device monitors the inlet and outlet temperatures of the phase change liquid and the temperature changes of the heat exchanger device itself in real time, and the temperature difference between the No. 1 temperature sensor 25 of the heat exchanger device and the No. 2 temperature sensor 26 of the heat exchanger device should be kept within 1.9°C. If the monitored value is greater than this value, it can be considered that the phase change liquid has fully phase changed and condensed and further cooled from a saturated liquid to a supercooled liquid, indicating that the flow rate of the cold fluid circuit of the heat exchanger device is too large and the cooling capacity is excessive. At this time, it is necessary to reduce the power of the cold flow liquid circuit water pump of the heat exchanger device to reduce the cooling capacity of the heat exchanger device; if the monitored value is less than this value or even close to zero, it can be considered that the phase change liquid has not fully phase changed and condensed into a saturated liquid, and is still a vapor phase change liquid or a gas-liquid two-phase mixed state, which means that the flow rate of the cold flow liquid circuit of the heat exchanger device is too small and the cooling capacity is insufficient. At this time, it is necessary to increase the power of the cold flow liquid circuit water pump of the heat exchanger device to improve the cooling capacity of the heat exchanger.

[0026] Heat storage mode: The controller 14 sends a heat storage control command to the system, only opening Figure 2 The phase change liquid in the liquid storage container 17 is gradually injected into the buried energy storage chamber 4 under the action of gravity. The liquid level sensor monitors the liquid level change in the buried energy storage chamber 4 in real time. When the liquid level of the phase change liquid 21 reaches the position of the second liquid level sensor 10, the controller 14 immediately issues a command to close the fourth and fifth solenoid valves while keeping the first solenoid valve 5 closed, and starts the variable frequency liquid pump 13. The above is the initial liquid volume preparation process and control method for the heat storage season.

[0027] After the initial liquid volume of the heat storage season is prepared, driven by the variable frequency liquid pump 13, the phase change liquid 21 in the underground energy storage chamber 4 is pumped to the heat exchanger device 3 by the variable frequency pump through the No. 2 liquid pipe 8, the No. 2 bypass pipe 23, the No. 3 bypass pipe 24, the No. 1 bypass pipe 22 and the No. 2 liquid pipe 8 in sequence. Under the heating action of the hot fluid liquid entering the inlet 18 of the heat exchanger device, the liquid 21 absorbs heat and changes phase to evaporate into steam, which enters the underground energy storage chamber 4 through the No. 1 liquid pipe 7. After the high-temperature steam contacts the inner wall of the underground energy storage chamber 4, it releases heat and changes phase to condense into liquid liquid, and finally flows back to the underground energy storage chamber 4. In this process, the inlet and outlet temperatures of the phase change liquid and the temperature of the heat exchanger device itself are monitored in real time by the temperature sensor of the heat exchanger device. The temperature difference between the No. 1 temperature sensor 25 of the heat exchanger device and the No. 2 temperature sensor 26 of the heat exchanger device should be kept within 1.9°C. If the result obtained is greater than this value, it means that the flow rate of the hot fluid liquid circuit of the heat exchanger device is too large and the heating capacity is excessive. It is necessary to reduce the power of the water pump of the hot fluid liquid circuit of the heat exchanger device to reduce the heating capacity of the heat exchanger device; if the result obtained is less than this value or even close to zero, it means that the flow rate of the hot fluid liquid circuit of the heat exchanger device is too small and the heating capacity is insufficient. It is necessary to increase the power of the water pump of the hot fluid liquid circuit of the heat exchanger device to improve the heating capacity of the heat exchanger device.

[0028] Liquid volume control mode during operation: during the operation of the system, if it is found that the phase change liquid level in the buried energy storage chamber 4 changes, resulting in the actual filling rate not being equal to the set filling rate, a control command must be issued through the controller 14. If the actual filling rate is greater than the set filling rate, when the No. 1, No. 2 and No. 5 solenoid valves are in the closed state, it is only necessary to open the No. 3 and No. 4 solenoid valves, and then start the variable frequency liquid pump 13 to send the excess phase change liquid in the buried energy storage chamber 4 to the liquid storage container 17, so that the filling rate in the buried energy storage chamber 4 can be always maintained at the set value; if the actual filling rate is less than the set filling rate, it is necessary to open the No. 2 to No. 5 solenoid valves while keeping the No. 1 solenoid valve in the closed state to replenish the phase change liquid into the buried energy storage chamber 4, so that the filling rate in the buried energy storage chamber 4 can be always maintained at the set value. Through this operation, the contact area between the liquid phase change liquid and the inner wall of the buried energy storage chamber 4 can be maintained in the cold storage mode, thereby improving the cold storage efficiency; the contact area between the vapor phase change liquid and the inner wall of the buried energy storage chamber 4 can also be maintained in the heat storage mode, thereby improving the heat storage efficiency.

[0029] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. The underground multi-mode drive energy storage system is characterized by: It includes an underground energy storage system, a liquid level control system and a heat exchanger device; The buried energy storage system comprises an energy storage device, a buried energy storage cavity and a high-efficiency thermal insulation layer, wherein the buried energy storage cavity is arranged in the body of the energy storage device, the high-efficiency thermal insulation layer covers the surface of the energy storage device and the upper part of the buried energy storage cavity, a No. 1 liquid level sensor is installed on the upper part of the buried energy storage cavity, and a No. 2 liquid level sensor is installed on the lower part of the buried energy storage cavity, a No. 1 liquid interface of the heat exchanger device is connected to one end of a No. 1 liquid pipe, and the other end of the No. 1 liquid pipe passes through the high-efficiency thermal insulation layer and enters the interior of the buried energy storage cavity, and the end face of the pipe mouth is higher than the upper part of the buried energy storage cavity and higher than the No. 1 liquid level sensor, a No. 2 liquid interface of the heat exchanger device is connected to one end of a No. 2 liquid pipe, and the other end of the No. 2 liquid pipe passes through the thermal insulation layer and enters the interior of the buried energy storage cavity, and the lower end of the pipe mouth is immersed in the phase change liquid and is located below the No. 2 liquid level sensor, and a No. 1 solenoid valve is installed on the No. 2 liquid pipe; The liquid level control system includes the liquid level and liquid quantity control system including three bypass pipelines, four solenoid valves, a variable frequency liquid pump and a liquid storage container; one port of the No. 1 bypass pipeline is connected to the No. 2 liquid pipe and the No. 2 liquid interface, and the other port of the No. 1 bypass pipeline is connected to the upper port of the liquid storage container, on which the No. 2 solenoid valve and the No. 4 solenoid valve are installed in sequence; one port of the No. 2 bypass pipeline is connected to the No. 2 liquid pipe, the No. 1 solenoid valve is located on the No. 2 liquid pipe between the No. 1 bypass pipeline and the No. 2 bypass pipeline, and the other port of the No. 2 bypass pipeline is connected to the lower port of the liquid storage container, and the No. 3 solenoid valve and the No. 5 solenoid valve are installed on the second bypass pipeline, one port of the No. 3 bypass pipeline is connected to the No. 1 bypass pipeline between the No. 2 solenoid valve and the No. 4 solenoid valve, and the other port of the No. 3 bypass pipeline is connected to the No. 2 bypass pipeline between the No. 3 solenoid valve and the No. 5 solenoid valve, and the variable frequency liquid pump is installed on the No. 3 bypass pipeline; The first and second liquid interfaces are provided with a first temperature sensor of the heat exchanger device and a second temperature sensor of the heat exchanger device, respectively, and a third temperature sensor of the heat exchanger device is installed in the middle; The heat exchanger's No. 1 to No. 3 temperature sensors, No. 1 and No. 2 liquid level sensors, No. 1 to No. 5 solenoid valves and variable frequency liquid pump are all connected to the controller via signal cables.

2. The underground multi-mode drive energy storage system according to claim 1, characterized in that: The No. 1 liquid pipe is provided with a liquid filling port.

3. The underground multi-mode drive energy storage system according to claim 1, characterized in that: The pipe opening at the other end of the No. 2 liquid pipe is connected to the filter.

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