Heat storage system and method of testing the same

Abstract

The application discloses a heat storage system and a testing method thereof, and relates to the technical field of heat storage systems. The heat storage system comprises an atomizer array, a vertical tank body, a heat storage body filled in the tank body, and a support structure arranged at the bottom of the heat storage body and used for bearing the heat storage body and allowing fluid to pass. The atomizer array is arranged at the top of the tank body and comprises a plurality of atomizing heads arranged along the cross section of the tank body. Each atomizing head is communicated with a total medium pipe through a liquid supply branch pipe. The total medium pipe is used for conveying heat transfer medium to each atomizing head, so that each atomizing head atomizes the heat transfer medium into uniform mist droplets and sprays the mist droplets to the surface of the heat storage body. The application can effectively inhibit the formation of channeling, channel flow and thermal short circuit, and effectively improve the heat exchange efficiency and heat volume utilization rate.

Description

Technical Field

[0001] This invention relates to the field of thermal storage system technology, and in particular to a thermal storage system and its testing method. Background Technology

[0002] Shower atomized bed thermal storage has become the mainstream technical solution in the field of medium- and low-temperature thermal storage due to its simple structure, low cost, and wide range of applicable materials. Traditional packed beds usually adopt bottom inlet and top outlet or submerged forced flow methods, which have the disadvantages of uneven fluid distribution, easy formation of channeling, troughing, and thermal short circuits, low heat exchange efficiency, and low utilization rate of effective thermal storage volume. Although existing spray heat exchange technology can improve the distribution, it still has the defects of uneven fluid distribution, easy formation of channeling, and thermal short circuits. Summary of the Invention

[0003] The purpose of this invention is to provide a thermal storage system and its testing method to solve the problems existing in the prior art, effectively suppress the formation of channeling, troughing and thermal short circuits, and improve the utilization rate of effective thermal storage volume and heat exchange efficiency.

[0004] To achieve the above objectives, the present invention provides the following solution: This invention provides a thermal storage system, including an atomizer array, a tank, a thermal storage body filled inside the tank, and a support structure disposed at the bottom of the thermal storage body for supporting the thermal storage body and allowing fluid to pass through; the atomizer array is disposed inside the tank and above the thermal storage body, the atomizer array includes a plurality of atomizing heads arranged along the cross-section of the tank, each atomizing head is connected to a total medium inlet, the total medium inlet is used to supply heat transfer medium to each atomizing head, and each atomizing head is used to atomize the heat transfer medium into droplets and spray them onto the surface of the thermal storage body.

[0005] In some embodiments, each of the atomizing heads is connected to the main airflow inlet via a gas supply branch pipe, and the main airflow inlet is used to supply high-pressure gas to each atomizing head; the atomizing head is a compression atomizer, which breaks the heat transfer medium into micron-sized droplets by mixing high-pressure gas with the heat transfer medium.

[0006] In some embodiments, a temperature measuring unit disposed inside the tank is further included, the temperature measuring unit comprising at least three height sections arranged along the axial direction of the tank and at least three temperature measuring elements arranged radially in each height section; The temperature measuring device is a thermocouple or a resistance temperature detector (RTD).

[0007] In some embodiments, a differential pressure transmitter is also included for measuring the pressure drop from the upper surface to the lower surface of the bed, the bed being formed by stacking the heat storage body.

[0008] In some embodiments, the tank body is cylindrical or rectangular, made of stainless steel / carbon steel, and has an insulation layer on the outer wall; The heat storage medium is one or more sensible heat materials such as basalt, ceramic balls, cast iron filings, and concrete blocks. The support structure is a grid or perforated plate, used to support the filler and allow fluid to flow through.

[0009] In some embodiments, it is applicable to scenarios such as solar thermal power generation and thermal storage, industrial waste heat recovery, clean heating, combined heat and power, and thermal energy storage and efficient heat exchange in energy storage power stations.

[0010] The present invention also provides a method for testing the heat storage and release performance of the thermal storage system as described above, comprising the following steps: The system undergoes cyclic heating and cooling to test the long-term stability and performance degradation of the thermal storage system.

[0011] In some embodiments, the bed is preheated or precooled to a set initial temperature before the initial heating. After starting the charging process, control the inlet temperature and flow rate, collect process data, and charge until the charging termination condition is met; After the heat release is started, the inlet temperature and flow rate are controlled, process data are collected, and heat release continues until the heat release termination condition is met.

[0012] In some embodiments, by changing the structural parameters and / or operating parameters, steps one to four are repeated to conduct variable parameter optimization experiments and obtain thermal storage and release performance data under different parameter conditions.

[0013] In some embodiments, after each heat charge and release, the method further includes: data processing to calculate heat storage and release performance indicators; The heat charging termination conditions are: the outlet temperature reaches the inlet temperature threshold, the predetermined heat storage capacity is reached, or the set operating time is reached. The heat release termination conditions are: the outlet temperature drops to the inlet temperature threshold, the predetermined heat release is reached, or the set operating time is reached.

[0014] The present invention achieves the following technical effects compared to the prior art: In this invention, an atomizer array replaces the traditional single nozzle or bottom-inlet method. Each atomizer head is arranged along the cross-section of the tank and supplied with liquid uniformly through the main medium inlet. This atomizes the heat transfer medium into uniform droplets. Compared to droplets sprayed by water pressure from ordinary sprayers, these droplets more evenly cover the entire bed cross-section. Under gravity, the droplets uniformly permeate through the gaps in the heat storage medium and fully contact the surfaces of each particle. Therefore, it effectively suppresses channeling and thermal short-circuiting, improving the utilization rate of the effective heat storage volume and heat exchange efficiency. Simultaneously, due to the small droplets, the contact area between the heat transfer medium and the heat storage medium per unit volume is significantly increased, thereby enhancing the heat exchange effect between the solid and liquid layers and improving the charging and releasing rates. Attached Figure Description

[0015] 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.

[0016] Figure 1 This is a schematic diagram of the structure of a thermal storage system provided in an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the application of thermal storage systems in China; In the diagram: 1-Media outlet; 2-Liquid accumulation layer; 3-Heat storage body; 4-Pressure stabilizing atomizing layer; 5-Feed inlet; 6-Atomizer array; 7-Pressure stabilizing port; 8-Total media inlet; 9-Total airflow inlet; 10-Insulation layer; 11-Discharge port; 12-Tank body; 13-Tank body support; 14-Drain outlet; 100-Heat storage system. Detailed Implementation

[0017] 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.

[0018] The purpose of this invention is to provide a thermal storage system and its testing method to solve the problems existing in the prior art, effectively suppress the formation of channeling, troughing and thermal short circuits, and improve the utilization rate of effective thermal storage volume and heat exchange efficiency.

[0019] 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.

[0020] The following is combined Figures 1 to 2 The following describes embodiments of the present invention.

[0021] Example 1 The present invention provides a heat storage system 100, including an atomizer array 6, a vertical tank 12, a heat storage body 3 filled inside the tank 12, and a support structure disposed at the bottom of the heat storage body 3 for supporting the heat storage body 3 and allowing fluid to pass through; the atomizer array 6 is disposed at the top of the tank 12 and includes a plurality of atomizing heads arranged along the cross-section of the tank 12, each atomizing head being connected to a total medium inlet 8 through a liquid supply branch pipe, the total medium inlet 8 being used to supply heat transfer medium to each atomizing head so that each atomizing head atomizes the heat transfer medium into uniform droplets and sprays them onto the surface of the heat storage body 3.

[0022] In this embodiment, because an atomizer array 6 is used instead of the traditional single nozzle or bottom liquid inlet method, and each atomizer head is arranged along the cross-section of the tank 12 and supplied with liquid uniformly through the total medium inlet 8, the heat transfer medium is atomized into uniform droplets that can cover the entire bed cross-section. Under the action of gravity, the droplets uniformly seep through the stacking gaps of the heat storage body 3 and make full contact with the surface of each particle. Therefore, it can effectively suppress the formation of channeling and thermal short circuits and improve the utilization rate of the effective heat storage volume. At the same time, due to the small droplets, the contact area between the heat transfer medium per unit volume and the heat storage body 3 is significantly increased, thereby enhancing the heat exchange effect between the solid and liquid and improving the charging and releasing rate.

[0023] In some embodiments, each atomizing head is connected to the main airflow inlet 9 via a gas supply branch pipe. The main airflow inlet 9 is used to supply high-pressure gas to each atomizing head. The atomizing head is a compression atomizer, which breaks the heat transfer medium into micron-sized droplets by mixing high-pressure gas with the heat transfer medium.

[0024] In this embodiment, since each atomizing head is connected to the main airflow inlet 9 through a gas supply branch pipe and adopts a gas-assisted atomization method, the high-pressure gas and the heat transfer medium are mixed inside the atomizing head or at the outlet. The shear force of the high-speed airflow is used to break the liquid into micron-sized droplets. Micron-sized droplets are lighter and fall more slowly, making them easier to diffuse with the airflow and uniformly adhere to the particle surface when passing through the gaps in the particle bed. This avoids the local scouring and channeling problems caused by the rapid settling of large droplets due to gravity. In addition, the droplet size of the compression atomization can be controlled online by adjusting the gas-liquid ratio. It can adapt to the atomization needs under different working conditions without replacing the atomizing head, and has higher operational flexibility.

[0025] The high-pressure gas can be compressed nitrogen or other inert gases to prevent the high-temperature heat transfer medium from oxidizing or deteriorating during atomization.

[0026] In some examples, the atomizing head may also be an ultrasonic atomizer, or any atomizer that can be arrayed and integrated.

[0027] In some embodiments, the thermal storage system 100 further includes a temperature measuring unit disposed inside the tank 12. The temperature measuring unit includes at least three height sections arranged along the axial direction of the tank 12 and at least three temperature measuring elements arranged radially in each height section.

[0028] In this embodiment, since at least three height sections are arranged axially inside the tank 12, and at least three temperature measuring elements are arranged radially in each section, a high-density multidimensional temperature measurement grid is formed in both the axial and radial directions. When the temperature front moves axially during the heat charging or releasing process, the measuring points at each height section can sequentially capture the time nodes of temperature jumps, thereby accurately calculating the moving speed of the temperature front. At the same time, the temperature difference of multiple measuring points radially within the same height section can intuitively reflect the temperature uniformity and stratification characteristics within that section. If the temperature of a measuring point in a certain area deviates significantly from that of other measuring points in the same section, it indicates that there is uneven fluid distribution or local thermal short-circuiting in that area. Therefore, high-density multidimensional temperature measurement can provide accurate experimental data support for evaluating the uniformity of liquid distribution in the system, diagnosing channeling and thermal short-circuiting, and verifying numerical simulation results.

[0029] Understandably, the number of axial temperature measuring points is not limited to three sections. It can be set to four, five, or more sections depending on the bed height and temperature measurement accuracy requirements. The higher the bed, the more sections are needed to capture the complete leading edge movement trajectory. The number of radial measuring points is also not limited to three. For large-diameter tanks 12, five or seven measuring points (including the center point and points near the wall) can be set to more precisely characterize the radial temperature distribution. Thermocouples or platinum resistance thermometers (RTDs) can be used as temperature measuring points. Thermocouples have fast response speeds and low cost, making them suitable for dynamic temperature measurement; RTDs offer higher accuracy and better stability, making them suitable for long-term cyclic testing. The temperature measuring points can be installed in an insertion manner (measuring points extend into the bed), a wall-mounted manner (measuring points are fixed to the inner wall of tank 12), or a suspended manner (measuring points are suspended in the gaps of the bed), depending on the bed stacking method and temperature measurement requirements. Furthermore, temperature sensors can be installed on the inlet and outlet pipes of tank 12, forming a three-dimensional temperature measurement network in conjunction with the measuring points inside the bed.

[0030] In some embodiments, when the atomizing head is a compressor atomizer, a pressure stabilizing port 7 is provided at the top of its canister 12. The pressure stabilizing port 7 is used to discharge internal non-condensable gases when the internal pressure exceeds a preset threshold, thereby maintaining the pressure of the canister 12 within a safe operating range. It is understood that a pressure relief valve is provided at the pressure stabilizing port 7. Of course, in some examples, a pressure relief valve may not be provided, and the pressure stabilizing port 7 can simply be a normally open exhaust port.

[0031] In some embodiments, the temperature measuring element is a thermocouple or a resistance temperature detector (RTD).

[0032] This embodiment provides a specific implementation method for the temperature measuring device. Besides thermocouples and resistance temperature detectors (RTDs), fiber Bragg grating temperature sensors can also be used. These sensors offer advantages such as electromagnetic interference resistance, corrosion resistance, and the ability to perform distributed continuous temperature measurement. They can simultaneously measure temperature at multiple locations along a single fiber, further simplifying wiring and increasing measurement density. In engineering applications where high temperature accuracy is not required, an infrared thermal imager can be used to non-contactly measure the surface temperature distribution of the bed through a 12-window viewing window in the tank. However, this method only obtains the surface temperature and cannot reflect the internal temperature field of the bed.

[0033] In some embodiments, the thermal storage system 100 further includes a differential pressure transmitter for measuring the pressure drop from the upper surface to the lower surface of the bed, which is formed by stacking thermal storage bodies 3.

[0034] In this embodiment, a differential pressure transmitter is installed from the upper surface to the lower surface of the bed, which can monitor the resistance change of the heat transfer medium flowing through the particle bed in real time during the charging and releasing processes. The pressure drop data and flow rate data can be combined to calculate the permeability and flow resistance coefficient of the bed. When the particles break, pulverize, or scale on the surface during long-term circulation, the porosity of the bed decreases, and the pressure drop will increase accordingly. Therefore, long-term monitoring of the pressure drop can indirectly reflect the integrity of the bed structure and the risk of blockage. At the same time, the pressure drop is directly related to the pump consumption. By measuring the pressure drop, the energy consumption of the system can be quantitatively assessed, providing data for optimizing the operating conditions, thereby achieving synergistic optimization of pressure drop and heat exchange efficiency.

[0035] As an alternative to this embodiment, multiple pressure measuring points can be set at different heights inside the bed to measure the pressure drop distribution in segments, thereby locating the main contributing sections of the pressure drop (such as the upper, middle, or bottom support structures of the bed). Pressure measurement can also be performed by using multiple absolute pressure sensors to measure the absolute pressure at the inlet and outlet respectively and then calculating the difference.

[0036] In some embodiments, the tank 12 is cylindrical or rectangular, made of stainless steel / carbon steel, and has an efficient heat insulation layer 10 on its outer wall; the heat insulation layer 10 may be ceramic fiber, rock wool, etc., wrapped on the outer wall of the tank 12 to minimize environmental heat loss and ensure test accuracy.

[0037] The heat storage body 3 is one or more sensible heat materials such as basalt, ceramic spheres, cast iron filings, and concrete blocks; the heat storage body 3 may also be a phase change material sphere of paraffin or molten salt encapsulated in metal or ceramic. The supporting structure is a grid or perforated plate, which is used to support the packing and ensure smooth fluid flow.

[0038] This embodiment further defines the structure of the tank 12, the supporting structure, and the composition of the heat storage body 3.

[0039] In some embodiments, electromagnetic flow meters / mass flow meters can also be installed on the pipeline to achieve high-precision metering.

[0040] In some embodiments, it is applicable to scenarios such as solar thermal power generation and thermal storage, industrial waste heat recovery, clean heating, combined heat and power, and thermal energy storage and efficient heat exchange in energy storage power stations.

[0041] In some embodiments, there needs to be a space between the top of the bed and the top of the tank 12, and between the bottom of the bed and the bottom of the tank 12, so as to form a pressure-stabilizing atomizing layer 4 at the top and a liquid accumulation layer 2 at the bottom.

[0042] In some embodiments, the tank body 12 is mounted on the tank support 13. The bottom of the tank body 12 is also provided with a drain port 14, and the side of the tank body 12 is provided with a feed port 5 and a discharge port 11. The feed port 5 is used to allow external particulate heat storage body 3 to enter the tank body 12, and the discharge port 11 facilitates the discharge of particulate heat storage body 3 from the inside of the tank body 12.

[0043] The tank body 12 is also provided with a medium outlet 1 at the bottom and a total medium inlet 8 and a total airflow inlet 9 at the top.

[0044] The usage process is as follows: 1. Heat storage process: After the heat is released, the heat transfer oil is sent to the heat source device through a circulating pump to be heated and then transported to the heat storage tank to exchange heat into the heat storage body 3, thus completing the heat release.

[0045] After releasing heat, the heat transfer oil is pumped back to the heat source device for reheating, and this cycle repeats continuously.

[0046] 2. Heat extraction process: After passing through an indirect heat exchanger, the high-temperature heat transfer oil exchanges heat with the heat users. The cooled heat transfer oil is then pumped into the heat storage tank and heat storage body 3 through a circulation pump to exchange heat, absorb heat and raise its temperature to become high-temperature heat transfer oil. It is then sent to the indirect heat exchanger to exchange heat with the heat users, and so on in a continuous cycle.

[0047] Example 2 This invention also provides a method for testing the heat storage and release performance of a thermal storage system, comprising the following steps: The system undergoes cyclic heating and cooling to test the long-term stability and performance degradation of the thermal storage system.

[0048] This embodiment can test the long-term stability and performance degradation of the thermal storage system.

[0049] In some embodiments, the bed is preheated or precooled to a set initial temperature before the first heating. After starting the charging process, control the inlet temperature and flow rate, collect process data, and charge until the charging termination condition is met; After the heat release is started, the inlet temperature and flow rate are controlled, process data are collected, and heat release continues until the heat release termination condition is met.

[0050] In this embodiment, the bed is adjusted to a uniform initial temperature through the above-mentioned systematic testing steps, eliminating the influence of uneven initial temperature on the test results and ensuring the comparability between different test cycles. The charging and releasing processes simulate the actual working process of the thermal storage system 100. By continuously collecting data, the changes in parameters such as temperature, pressure, and flow rate over time can be completely recorded. By repeatedly executing the charging-releasing cycle, the performance change trend of the system after multiple cycles can be evaluated, including whether the heat exchange power decreases, whether the pressure drop increases, and whether the thermal storage density decreases, thereby providing data support for the long-term operational reliability and maintenance cycle of the system.

[0051] In some embodiments, steps one to four are repeated by changing structural parameters and / or operating parameters to conduct variable parameter optimization experiments and obtain thermal storage and release performance data under different parameter conditions.

[0052] In this embodiment, by systematically changing structural parameters (such as particle size, bed height, atomizer arrangement, etc.) and operating parameters (such as inlet temperature, heat transfer medium flow rate, etc.) in the variable parameter optimization experiment, and repeatedly executing the complete charge and discharge heat test process, the influence of each parameter on performance indicators such as heat storage density, power density, thermal efficiency, pressure drop and pump consumption can be obtained. This establishes a mapping relationship between multiple parameters and performance, and the optimal combination of structural and operating parameters can be selected accordingly, providing a design basis for scaling up the system from laboratory scale to industrial production.

[0053] Structural parameters can be changed by replacing the particle material with one of different sizes, changing the bed filling height, or replacing the support plate with one of different porosity. Operating parameters can be changed by adjusting the variable frequency pump speed (changing the flow rate) and the temperature control device setting (changing the inlet temperature). Alternatively, a single-factor rotation method (changing only one parameter at a time while keeping the others fixed) can be used to test each parameter individually to clearly obtain the independent influence of each parameter.

[0054] In some examples, the parameters that can be changed include: inlet fluid temperature, shower atomization flow rate, type of filler material, particle size, bed height, bed diameter, porosity, shower atomizer type, porosity, and installation height.

[0055] In some embodiments, after each heat charge and release, the method further includes: data processing to calculate heat storage and release performance indicators.

[0056] In this embodiment, by processing the raw data such as temperature, pressure, and flow rate collected during the heat charging and heat release processes, and using the energy balance equation and basic fluid mechanics formulas for calculation, discrete sensor data can be transformed into heat storage and release performance indicators with clear physical meaning. This allows test results under different operating conditions, materials, and structures to be compared horizontally under the same standard system, providing a quantitative basis for system performance evaluation and optimization direction judgment.

[0057] In some examples, calculable performance metrics include: charge / release power, cumulative heat storage, cumulative heat release, charge / release time, temperature front movement speed, temperature stratification, charge / release efficiency, cycle efficiency, effective heat storage density, power density, bed pressure drop, pump power consumption, and performance degradation rate.

[0058] In some embodiments, the system heat loss can also be quantitatively assessed by static insulation tests or energy balance methods, and compensation corrections can be made in performance calculations.

[0059] In some embodiments, the heat charging termination condition is that the outlet temperature reaches the inlet temperature threshold, the predetermined heat storage capacity is reached, or the set operating time is reached. The heat release termination conditions are: the outlet temperature drops to the inlet temperature threshold, the predetermined heat release is reached, or the set operating time is reached.

[0060] In this embodiment, by setting multiple optional termination conditions, the heat charging and releasing processes can be terminated by temperature (the outlet temperature approaches the inlet temperature, indicating that the bed is sufficiently thermally or coldly saturated), energy (the target heat storage / release capacity is reached), or time (a fixed running time), to adapt to different testing objectives and operating conditions. Temperature-driven termination is suitable for testing the maximum heat storage capacity of the system; energy-driven termination is suitable for simulating the on-demand heat storage / release operation mode in actual engineering; and time-driven termination is suitable for comparing the heat storage / release performance of different systems within the same operating time. The coexistence of these three termination conditions ensures testing flexibility.

[0061] 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 thermal storage system, comprising a tank, a thermal storage body filled inside the tank, and a support structure disposed at the bottom of the thermal storage body for supporting the thermal storage body and allowing fluid to pass through; characterized in that, It also includes an atomizer array, which is disposed inside the tank and above the heat storage body. The atomizer array includes a plurality of atomizing heads arranged along the cross-section of the tank. Each atomizing head is connected to a total medium inlet, which supplies heat transfer medium to each atomizing head. Each atomizing head is used to atomize the heat transfer medium into droplets and spray them onto the surface of the heat storage body.

2. The thermal storage system according to claim 1, characterized in that: Each of the atomizing heads is connected to the main airflow inlet via a gas supply branch pipe. The main airflow inlet is used to supply high-pressure gas to each atomizing head. The atomizing head is a compression atomizer, which breaks the heat transfer medium into micron-sized droplets by mixing the high-pressure gas with the heat transfer medium.

3. The thermal storage system according to claim 1, characterized in that: It also includes a temperature measuring unit disposed inside the tank, the temperature measuring unit comprising at least three height sections arranged along the axial direction of the tank and at least three temperature measuring elements arranged radially in each height section; The temperature measuring device is a thermocouple or a resistance temperature detector (RTD).

4. The thermal storage system according to claim 1, characterized in that: It also includes a differential pressure transmitter for measuring the pressure drop from the upper surface to the lower surface of the bed, which is formed by the accumulation of the heat storage body.

5. The thermal storage system according to claim 1, characterized in that: The tank body is cylindrical or rectangular, made of stainless steel / carbon steel, and has an insulation layer on the outer wall; The heat storage medium is one or more sensible heat materials such as basalt, ceramic balls, cast iron filings, and concrete blocks. The support structure is a grid or perforated plate, used to support the filler and allow fluid to flow through.

6. The thermal storage system according to claim 1, characterized in that: It is suitable for solar thermal power generation and heat storage, industrial waste heat recovery, clean heating, combined heat and power, and energy storage and efficient heat exchange scenarios in energy storage power stations.

7. A method for testing the heat storage and release performance of a thermal storage system according to any one of claims 1 to 6, characterized in that, Includes the following steps: The system undergoes cyclic heating and cooling to test the long-term stability and performance degradation of the thermal storage system.

8. The test method according to claim 7, characterized in that: Before the initial heating, preheat or precool the bed to the set initial temperature. After starting the charging process, control the inlet temperature and flow rate, collect process data, and charge until the charging termination condition is met; After the heat release is started, the inlet temperature and flow rate are controlled, process data are collected, and heat release continues until the heat release termination condition is met.

9. The test method according to claim 7, characterized in that: By repeating steps one through four with changes in structural and / or operating parameters, variable parameter optimization experiments are conducted to obtain data on heat storage and release performance under different parameter conditions.

10. The test method according to claim 8, characterized in that: After each heat charging and releasing process, the process also includes: data processing, and calculation of heat storage and release performance indicators; The heat charging termination conditions are: the outlet temperature reaches the inlet temperature threshold, the predetermined heat storage capacity is reached, or the set operating time is reached. The heat release termination conditions are: the outlet temperature drops to the inlet temperature threshold, the predetermined heat release is reached, or the set operating time is reached.

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