Composite hydrated salt heat storage material preparation device and control method thereof

Abstract

The application discloses a kind of composite hydrated salt heat storage material preparation device and control method thereof, belong to composite hydrated salt heat storage material preparation technical field, including preparation container and salt solution preparation container, preparation container has the accommodating cavity of top opening, target adsorbent is placed in accommodating cavity, target adsorbent is porous working substance frame material not loaded metal salt, for as the carrier skeleton of composite hydrated salt heat storage material, salt solution preparation container is connected to the top of accommodating cavity by water pump and salt solution injection pipeline, and salt solution preparation container is used to accommodate the mixed solution of water and metal salt.The application can realize the production of "porous adsorption carrier (such as zeolite) loaded metal salt hydrated salt to form composite working pair", replace laboratory manual operation, ensure the consistency and repeatability of product ratio.

Description

Technical Field

[0001] This invention relates to the field of composite hydrated salt thermal storage material preparation technology, and particularly to a composite hydrated salt thermal storage material preparation device and a method for preparing the composite hydrated salt thermal storage material preparation device. Background Technology

[0002] Thermal energy storage technologies are mainly classified into three categories: sensible heat storage, latent heat storage, and thermochemical heat storage. Among them, thermochemical heat storage utilizes special materials as adsorbents, achieving the storage and utilization of thermal energy through two reversible reactions—dehydration and hydration—during heat absorption and release. It boasts significant advantages such as high heat storage density (up to 600 kJ / kg or more), a wide operating temperature range, long-term heat storage capability, and low heat loss. Using porous materials such as zeolites as carriers, loading a certain amount of non-toxic metal salts (such as MgCl2, CaCl2, etc.) to form composite working fluid pairs, represents a promising large-capacity, high-performance thermal energy storage method.

[0003] The inventors, through searching, found that the most relevant prior art to this application is the formulation and laboratory preparation method of composite hydrated salt thermal storage materials, as detailed below: (1) Chinese patent application (publication number CN110079280A) discloses a composite thermal storage material of binary hydrated salt. This patent discloses a composite thermal storage material using zeolite 13X or activated carbon particles as a carrier and filled with a binary mixed salt of MgCl2 and CaCl2. The preparation method is as follows: the porous material is dried at 150°C for 2-4 hours and then cooled and sealed; it is immersed in a mixed solution of MgCl2 and CaCl2 with a total concentration of 20wt% and vacuum impregnated for 2 hours; the surface salt is removed by washing with ethanol, and the material is dried at room temperature for 24 hours and then dried at 150°C for 24-48 hours. This method can improve the thermal storage density and reduce heat loss, and is suitable for cross-seasonal thermal storage.

[0004] (2) US Patent Application (Publication No. US20180237678A1) discloses a composite material for thermochemical heat storage and its preparation method. This patent discloses a composite heat storage material and its formation method in which hydrated salt is directly arranged on a porous substrate (such as attapulgite or activated carbon). The preparation process includes: adding the salt solution dropwise to the thermally activated substrate and reacting continuously for 48-72 hours under stirring at 150 rpm. This scheme discusses the high hydrothermal stability and heat storage density advantage (approximately 220 kWh / m³) of zeolite as the substrate. 3 However, it is noted that the zeolite regeneration temperature is relatively high (usually greater than 110°C), therefore salt-based composite materials are preferred.

[0005] (3) US Patent Application (Publication No. US20240183623A1) discloses a salt hydrate composite material for thermochemical thermal storage and its preparation method. This patent discloses a method for preparing hydrated salt composite thermal storage materials by dry mixing / ball milling (without adding water), using a substrate (such as graphene oxide, expanded graphite, vermiculite, etc.) and a binder; the scheme discusses the energy density (approximately 100-200 kWh / m³) of zeolite and silica gel as adsorption thermochemical thermal storage materials. 3 However, the key is to solve the problems of salt deliquescence, swelling and agglomeration through dry processes.

[0006] Option 2: Automatic preparation and concentration control device for salt solutions (4) Chinese patent application (authorization announcement number CN216630414U) discloses an automatic preparation system for a fixed concentration solution of soluble salts. The patent discloses an automatic preparation system for a fixed concentration solution of salts, including an auger automatic feeder, a dissolving tank (including a stirrer and a level gauge), a clear water tank and a storage tank. The target solution concentration is precisely controlled by setting the instrument, and the feeding, dissolving, diluting and conveying are fully automatic. The system is designed for the preparation of general chemical solutions, but does not have a soaking and adsorption process for porous adsorbents, nor does it involve the multi-parameter coordinated control of solution concentration, temperature and level during the soaking process.

[0007] Direction 3: Multi-parameter cooperative control method (5) Chinese patent application (publication number CN109999527A) discloses a multi-fluid intelligent batching control method. This patent discloses a multi-fluid batching control method for distillation / reactor processes, which performs segmented fuzzy logic collaborative control of temperature, pressure, liquid level, and flow rate. This solution is applied to chemical distillation and reactor scenarios, but does not involve the concentration-temperature-liquid level three-closed-loop linkage control in the porous material soaking and adsorption process, nor does it involve the specific process of circulating solution soaking and overflow recovery.

[0008] In summary, existing technologies mainly focus on: (a) the formulation of composite hydrated salt thermal storage materials and laboratory manual preparation methods (vacuum impregnation, dropwise stirring, dry ball milling), (b) general chemical solution automatic preparation systems, and (c) general multi-parameter control methods for distillation / reaction vessels. There are no published documents or patents describing preparation devices specifically for the specific process scenario of "forming composite thermal storage working fluid pairs by loading hydrated salts onto porous adsorption carriers", especially dedicated equipment that integrates solution circulation soaking, overflow recovery, and three-closed-loop coordinated control of liquid level, temperature, and concentration.

[0009] Based on the above-mentioned existing technologies, the following core defects exist when moving composite hydrated salt thermal storage materials from the laboratory to industrial production: (1) No dedicated automated preparation equipment: The preparation methods described in the existing patent documents (CN110079280A, US20180237678A1 and US20240183623A1) are all manual operations in the laboratory (vacuum impregnation, long-term drop stirring, dry ball milling), which rely on manual control of each process parameter and cannot guarantee the consistency of products and the stability of the ratio between batches.

[0010] (2) Separation of solution preparation and adsorption soaking process: The existing general solution preparation device (CN216630414U) can only complete the preparation of salt solution of fixed concentration. It does not have the function of placing the target adsorbent (zeolite carrier) into it for controlled soaking and adsorption, and cannot realize the integrated continuous preparation from "solution preparation → soaking → adsorption → circulation adjustment".

[0011] (3) Multi-parameter control methods are not suitable for immersion adsorption scenarios: The existing general multi-parameter control scheme (CN109999527A) is geared towards distillation / reactor scenarios and does not design a coordinated control strategy for the cascade coupling relationship between the liquid level drop (the solution is absorbed by the adsorbent), the concentration drop (salt is trapped by the adsorbent), and the temperature change (adsorption exothermic / environmental heat dissipation) during the process of "solution immersion in porous adsorbent".

[0012] (4) Lack of circulating solution and concentration compensation mechanism: Laboratory manual preparation usually involves a single soaking. During the soaking process, the solution concentration continuously decreases as the adsorption progresses, resulting in uneven salt loading inside the adsorbent. Existing technologies do not propose a scheme to maintain a stable soaking solution concentration through solution circulation and real-time concentration compensation. Summary of the Invention

[0013] Firstly, the technical problem to be solved by the present invention is to provide a device for preparing composite hydrated salt thermal storage materials, so as to realize the production of "composite working fluid pairs formed by loading metal hydrates with porous adsorption carriers (such as zeolites) to form composite working fluid pairs", replacing manual operation in the laboratory and ensuring the consistency and repeatability of product ratio.

[0014] To solve the aforementioned technical problem in the first aspect, the present invention adopts the following solution: a composite hydrated salt thermal storage material preparation device, comprising a preparation container and a salt solution preparation container. The preparation container has a cavity with a top opening, in which a target adsorbent is placed. The target adsorbent is a porous working fluid skeleton material without metal salt loading, used as a carrier skeleton for the composite hydrated salt thermal storage material. The salt solution preparation container is connected to the top of the cavity through a water pump and a salt solution injection pipe. The salt solution preparation container is used to contain a mixture of water and metal salt.

[0015] Furthermore, the above-mentioned preparation container is equipped with an adsorbent storage rack, in which the adsorbent can be stored. The bottom of the adsorbent storage rack is provided with support legs, and the top is provided with a cover plate. A salt solution injection port is provided in the middle of the cover plate. The salt solution injection port is connected to a salt solution injection pipe. After the salt solution enters the preparation container, it can soak the adsorbent in the adsorbent storage rack.

[0016] Furthermore, the aforementioned adsorbent storage mesh frame includes a bottom double-ring mesh and a middle double-ring mesh. The bottom double-ring mesh includes a bottom sealing plate and a first inner ring mesh cover and a first outer ring mesh cover coaxially arranged on the bottom sealing plate 2303. Support legs are set at the bottom of the bottom double-ring mesh to suspend and support the adsorbent storage mesh frame. The upper ends of the first inner ring mesh cover and the first outer ring mesh cover are respectively provided with a first external thread and a first internal thread. The middle double-ring mesh includes a second inner ring mesh cover and a second outer ring mesh cover. The second inner ring mesh cover and the second outer ring mesh cover are fixedly connected near the bottom by multiple circumferentially evenly arranged spokes. The lower ends of the second inner ring mesh cover and the second outer ring mesh cover are respectively provided with a second internal thread and a second external thread. The upper ends of the second inner ring mesh cover and the second outer ring mesh cover are respectively provided with a third external thread and a third internal thread. The threaded openings, the first external thread and the first internal thread, can be spirally connected to the second internal thread and the second external thread, respectively. The middle section of the double ring mesh is spliced ​​in multiple ways. The second internal thread and the second external thread at the lower end of the upper middle section of the double ring mesh can be spirally connected to the third external thread and the third internal thread at the upper part of the lower middle section of the double ring mesh, respectively. The bottom of the cover plate is provided with a fourth internal thread and a fourth external thread, which can be spirally connected to the third external thread and the third internal thread, respectively. The outer diameter of the cover plate maintains a clearance fit with the inner diameter of the preparation container. After the multiple middle section double ring meshes and the bottom double ring mesh are spliced ​​together, a storage cavity is formed between the inner and outer ring meshes. After the target adsorbent is placed into the storage cavity, it is covered by the cover plate. The cover plate is provided with vent holes around its circumference, and the vent holes are located outside the storage cavity.

[0017] Furthermore, the aforementioned salt solution is equipped with a container fitted with a stirrer for stirring the solution and a heater for heating the solution.

[0018] Furthermore, the aforementioned raw material supply subsystem includes a hydrated salt silo, an electrically controlled feed switch, a clean water container, and an electrically controlled water valve. The hydrated salt silo is used to store metal salt particles or powder to be loaded. The hydrated salt silo is installed above the salt solution preparation container and is connected to the salt solution preparation container via an electrically controlled feed switch and a salt addition pipe. The clean water container is connected to the salt solution preparation container via a pump and a water injection pipe, on which an electrically controlled water valve is installed.

[0019] Furthermore, the container for the aforementioned salt solution is equipped with a temperature sensor for measuring the solution temperature, a liquid level sensor for measuring the solution level, and a salt concentration sensor for measuring the solution salt concentration.

[0020] Furthermore, the aforementioned temperature sensor, liquid level sensor, and salt concentration sensor are connected to the main controller, which in turn is connected to the water pump, pump, electrically controlled feed switch, electrically controlled water valve, heater, and agitator.

[0021] Furthermore, the aforementioned preparation container is fixedly connected to the left side of the support frame, the salt solution preparation container is fixedly connected to the right side of the support frame, and the hydrated salt silo is fixedly connected to the support frame located above the salt solution preparation container.

[0022] Secondly, the technical problem to be solved by the present invention is to provide a control method for a composite hydrated salt thermal storage material preparation device, so as to achieve precise control of salt solution and precise control of adsorption, with close changes in salt concentration, and to ensure the adsorption consistency of the adsorption material.

[0023] To solve the aforementioned technical problem in the second aspect, the present invention adopts the following solution: a method for preparing a composite hydrated salt thermal storage material preparation device, the method comprising the following steps: Step 1: Place the target adsorbent into the preparation container and set the required process parameters: immersion solution temperature, salt solution concentration, liquid level, and adsorption time; Step 2, Salt solution preparation: Pour clean water into the container for preparing the salt solution, monitor the liquid level in real time, and stop pouring clean water when the preset liquid level is reached. Then stir and heat the container for preparing the salt solution, and stop heating when the water temperature reaches the preset temperature. Add the set amount of metal salt to the container for preparing the salt solution, and dissolve it under stirring. Stop adding metal salt when the salt concentration reaches the preset concentration. The initial salt solution preparation is complete. Step 3, Circulating Immersion Adsorption: The salt solution in the salt solution preparation container is pumped into the preparation container through the salt solution injection pipe. The solution gradually immerses the target adsorbent in the preparation container. When the liquid level in the preparation container is higher than the outlet of the recovery pipe, the solution flows back to the salt solution preparation container through the recovery pipe, forming a solution circulation. Step 4: After the preset adsorption time is reached, remove the target adsorbent from the preparation container and let it dry to obtain the finished composite hydrated salt thermal storage material.

[0024] Furthermore, the above-mentioned liquid level control: continuously monitor the liquid level in the salt solution container, and if it falls below the preset value by more than 1 cm, add clean water to the salt solution container to the preset liquid level; salt concentration control: continuously monitor the solution concentration in the salt solution container, and if it falls below the preset value by more than 2%, add metal salt to the salt solution container to the preset concentration; temperature control: continuously monitor the solution temperature in the salt solution container, and if it falls below the preset value by more than 1°C, heat the salt solution in the salt solution container to the preset temperature.

[0025] Compared with the prior art, the advantages of the present invention are as follows: (1) The present invention prepares a container to place the target adsorbent. The salt solution to be adsorbed is prepared in the container and then pumped into the preparation container. The target adsorbent adsorbs the salt solution to form a composite hydrated salt heat storage material. The solution is circulated in conjunction with the raw material supply subsystem and the recovery pipeline to ensure the stability of the salt solution preparation, ensure the consistency of the salt solution during the adsorption process, and improve the adsorption uniformity, thereby greatly improving the production efficiency and product consistency. (2) Three-loop collaborative control ensures stable product quality: In view of the cascade coupling characteristics of liquid level, salt concentration and temperature during the adsorbent soaking process, a special collaborative control strategy is designed to continuously maintain the stability of process parameters in the dynamic process, and realize the fully automated preparation of composite hydrated salt thermal storage materials: The laboratory manual operation (vacuum impregnation, long-term drip stirring) is transformed into one-click automatic production. The operator only needs to place the adsorbent, set the parameters and take out the finished product to ensure that the salt load of different batches of products is consistent. (3) The salt solution is recycled to solve the problem of uneven adsorption: the solution is continuously circulated between the preparation container and the salt solution container, and real-time concentration compensation is used to avoid uneven adsorption caused by local concentration decay of the solution during static soaking, so that the salt distribution inside the adsorbent is more uniform. (4) The salt solution preparation is highly integrated and easy to operate: the preparation, heating, stirring, soaking, circulation and recycling are all integrated into a single device. The human-machine interactive touch interface allows for intuitive parameter setting, reducing the requirements for the professional skills of the operators. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural schematic diagram of a composite hydrated salt thermal storage material preparation device according to Embodiment 1 of this application; Figure 2 This is an isometric view of the apparatus for preparing a composite hydrated salt thermal storage material according to Embodiment 1 of this application; Figure 3 This is a front view schematic diagram of a composite hydrated salt thermal storage material preparation device according to Embodiment 1 of this application; Figure 4 This is a top view schematic diagram of a composite hydrated salt thermal storage material preparation device according to Embodiment 1 of this application; Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure of the middle AA section; Figure 6 This is a schematic diagram of the principle connection of a composite hydrated salt thermal storage material preparation device in Embodiment 1 of this application; Figure 7 This is a schematic diagram of the cross-sectional structure of the container prepared in Embodiment 1 of this application; Figure 8This is a schematic diagram of the cover plate structure of the adsorbent storage mesh rack in Embodiment 1 of this application; Figure 9 This is a schematic cross-sectional view of the adsorbent storage grid structure in Embodiment 1 of this application; Figure 10 This is a schematic diagram of the bottom double-ring mesh cross-sectional structure in Embodiment 1 of this application; Figure 11 This is a schematic diagram of the cross-sectional structure of the middle section of the double-ring network in Embodiment 1 of this application; Figure 12 This is a top view of the double-ring network structure in the middle section of Embodiment 1 of this application; Figure 13 This is a schematic diagram of the cross-sectional structure of the pressure plate in Embodiment 1 of this application; Figure 14 This is a schematic diagram of the control principle of the device for preparing composite hydrated salt thermal storage materials. Detailed Implementation

[0027] The present invention will now be described in detail with reference to specific embodiments.

[0028] Example 1: As Figure 1-14 As shown, a device for preparing composite hydrated salt thermal storage material includes a preparation container 1 and a salt solution preparation container 6. The preparation container 1 has a cavity 101 with a top opening, in which a target adsorbent 2 is placed. The preparation container is made of a corrosion-resistant material and can hold one or more target adsorbents. The target adsorbent 2 is a porous working fluid frame material without metal salt loading, used as the carrier skeleton of the composite hydrated salt thermal storage material. The target adsorbent 2 allows the metal salt solution to enter its porous structure through an immersion adsorption process, and after drying, a composite working fluid pair is formed. The salt solution preparation container 6 is connected to the top opening of the cavity 101 through a water pump 5 and a salt solution injection pipe 16. The salt solution preparation container 6 is used to hold a mixture of water and metal salt. Through this device, the salt solution can be prepared as needed and sent into the preparation container to prepare the composite hydrated salt thermal storage material. The preparation container 1 is fixedly connected to the left side of the support frame 21, and the salt solution preparation container 6 is fixedly connected to the right side of the support frame 21.

[0029] In order to form a recyclable salt solution and ensure the homogeneity of the salt solution, such as Figure 7As shown, the preparation container 1 has a drain outlet 22 at its bottom. The drain outlet 22 is connected to the salt solution preparation container 6 via a recovery pipe 17. The liquid is recovered when the outlet of the recovery pipe 17 is lower than the immersion liquid surface near the target adsorbent 2. That is, when the liquid level in the preparation container is higher than the outlet of the recovery pipe, the solution automatically flows back to the salt solution preparation container through the recovery pipe, thus recovering the salt solution into the salt solution preparation container 6, forming a cycle. This cycle, along with online karstification monitoring and automatic salt addition, automatically adjusts the salt solubility of the salt solution to ensure balanced karstification adsorption (as the target adsorbent 2 in the preparation container...). As the adsorbent adsorbs, the salt solubility of the salt solution changes (decreases). Therefore, it is necessary to circulate and add salt solution and automatically adjust the salt solubility. An adsorbent storage rack 23 is placed in the preparation container 1. The adsorbent 2 can be stored in the adsorbent storage rack 23. The bottom of the adsorbent storage rack 23 is provided with support legs 24 and the top is provided with a cover plate 25. A salt solution injection port 26 is provided in the middle of the cover plate 25. The salt solution injection port 26 is connected to the salt solution injection pipe 16. After the salt solution enters the preparation container 1, it can soak the adsorbent 2 in the adsorbent storage rack 23.

[0030] To facilitate the 3D printing of the adsorbent storage mesh and avoid the difficulty in fabrication due to the mesh being too tall (up to 1m), the adsorbent storage mesh 23 is designed as a segmented structure, such as... Figure 7-13As shown, specifically, the adsorbent storage mesh frame 23 includes a bottom double-ring mesh 2301 and a middle double-ring mesh 2302. The bottom double-ring mesh 2301 includes a bottom sealing plate 2303 and a first inner annular mesh cover 2304 and a first outer annular mesh cover 2305 coaxially arranged with the bottom sealing plate 2303. Support legs 24 are arranged at the bottom of the bottom double-ring mesh 2301 to suspend and support the adsorbent storage mesh frame 23. The upper ends of the first inner annular mesh cover 2304 and the first outer annular mesh cover 2305 are respectively provided with a first external threaded opening 2306 and a first internal threaded opening 2307. The segmented double-ring mesh 2302 includes a second inner ring mesh cover 2308 and a second outer ring mesh cover 2309. The second inner ring mesh cover 2308 and the second outer ring mesh cover 2309 are fixedly connected near their bottom ends by multiple circumferentially evenly arranged spokes 2310. The lower ends of the second inner ring mesh cover 2308 and the second outer ring mesh cover 2309 are respectively provided with a second internal thread opening 2311 and a second external thread opening 2312. The upper ends of the second inner ring mesh cover 2308 and the second outer ring mesh cover 2309 are respectively provided with a third external thread opening 2313 and a third internal thread opening 231. 4. The first external threaded port 2306 and the first internal threaded port 2307 can be spirally connected to the second internal threaded port 2306 and the second external threaded port 2307, respectively. The middle section double ring mesh 2302 adopts multiple splices. The second internal threaded port 2311 and the second external threaded port 2312 at the lower end of the upper middle section double ring mesh 2302 can be spirally connected to the third external threaded port 2313 and the third internal threaded port 2314 at the upper section of the lower middle section double ring mesh 2302, respectively. The bottom of the cover plate 25 is provided with a fourth internal threaded port 2501 and a fourth external threaded port 2502. The fourth internal thread port 2501 and the fourth external thread port 2502 can be spirally connected to the third external thread port 2313 and the third internal thread port 2314 at the upper end of the middle section double ring net 2302, respectively. The outer diameter of the cover plate 25 maintains a clearance fit with the inner diameter of the preparation container 1. After multiple middle section double ring nets 2302 and bottom double ring nets 2302 are spliced ​​together, a storage cavity 2315 is formed between the inner and outer ring nets. After the target adsorbent 2 is placed into the storage cavity 2315, it is covered with the cover plate. The cover plate is provided with vent holes 2503 around its circumference. The vent holes are located outside the storage cavity.

[0031] To improve the uniformity of the salt solution preparation and meet temperature requirements, the salt solution container 6 is equipped with a stirrer 7 for stirring the solution and a heater 8 for heating the solution. The stirrer 7 includes a stirring blade, a stirring shaft, and a stirring motor. The stirring motor is fixedly connected to the middle of the top cover of the salt solution container 6. The motor shaft of the stirring motor is fixedly connected to the upper end of the stirring shaft, and the stirring blade is fixedly connected to the lower end of the stirring shaft. The heater 8 is installed at the bottom of the salt solution container 6 and continuously stirs the solution to ensure uniformity during water injection, salt addition, and circulation adjustment. The heater heats the salt solution to a preset temperature and maintains stability through a temperature closed loop.

[0032] To facilitate the preparation of the salt solution, a raw material supply subsystem is installed on the top of the salt solution preparation container 6. The raw material supply subsystem includes a hydrated salt silo 3, an electrically controlled feed switch 4, a clean water container 11, and an electrically controlled water valve 12. The clean water container 11 stores clean water for preparation. The hydrated salt silo 3 is fixedly connected to the support frame 21 located above the salt solution preparation container 6. The hydrated salt silo 3 is used to store the metal salt particles or powder to be loaded. The hydrated salt silo 3 is installed above the salt solution preparation container 6 and is connected to the salt solution preparation container 6 through the electrically controlled feed switch 4 and the salt addition pipe 18. The clean water container 11 is connected to the salt solution preparation container 6 through a pump and a water injection pipe 13. An electrically controlled water valve 12 is installed on the water injection pipe 13. The hydrated salt silo 3 and the electrically controlled feed switch 4 facilitate the rapid addition of metal salts, while the clean water container 11 and the electrically controlled water valve 12 facilitate the injection of clean water into the salt solution preparation container 6.

[0033] To facilitate the monitoring of the temperature, level, and salt concentration of the salt solution, the salt solution container 6 is equipped with a temperature sensor 10 for measuring the solution temperature, a level sensor 20 for measuring the solution level, and a salt concentration sensor 9 for measuring the solution salt concentration. The level sensor 20 is mounted on the top cover of the salt solution container 6. The temperature sensor 10 uses a thermocouple with its probe positioned below the liquid surface. Both the temperature sensor 10 and the salt concentration sensor 9 are mounted on the side wall of the salt solution container 6, with the probe of the salt concentration sensor 9 also positioned below the liquid surface. Through the temperature sensor 10, level sensor 20, and salt concentration sensor 9, the temperature, level, and salt concentration of the salt solution can be monitored in real time. Based on changes in these parameters, corresponding controls are implemented for the heater, water injection, and the addition of metal salt, resulting in more precise control. The main controller 14 is the core decision-making unit of the system, responsible for executing the control algorithm, collecting sensor data, driving all actuators (electrically controlled feed switch, electrically controlled water valve, stirrer, heater, and water pump), and running the three-closed-loop collaborative control logic.

[0034] For ease of automated control, temperature sensor 10, liquid level sensor 20, and salt concentration sensor 10 are connected to main controller 14. Main controller 14 is connected to water pump 5, pump, electrically controlled feed switch 4, electrically controlled water valve 12, heater 8, and stirrer 7 (stirring motor of stirrer), as well as human-machine interface 15 (touch screen). Main controller 14 is also connected to power supply 19, which supplies power to water pump 5, pump, electrically controlled feed switch 4, electrically controlled water valve 12, heater 8, stirrer 7, and human-machine interface 15. The main controller monitors the temperature, liquid level, and salt concentration changes of the salt solution, and then controls the heater, electrically controlled feed switch 4, and electrically controlled water valve 12 accordingly. It performs automated monitoring and control of temperature, liquid level, and salt concentration, as well as automated injection of the target adsorbent into the salt solution, automatic control of adsorption time, parameter setting via human-machine interface, and audible and visual alarm.

[0035] This embodiment discloses a composite hydrated salt thermal storage material preparation device, which can realize the fully automated production of "metal hydrated salt loaded with porous adsorbent carrier (such as zeolite) to form a composite working fluid pair", replacing manual operation in the laboratory and ensuring the consistency and repeatability of product ratio.

[0036] Example 2: A method for preparing a composite hydrated salt thermal storage material preparation device, the method comprising the following steps: Step 1: The operator places the target adsorbent 2 (porous working fluid material such as zeolite without metal salt loading) into the adsorbent storage mesh rack 23, covers it with a cover plate, and then places it into the preparation container 1. The power supply 19 of the preparation device is turned on, and the main controller 14 performs a self-test and drives the human-machine interface 15 to enter the running state. The operator sets the required process parameters on the human-machine interface 15 (touch screen): soaking solution temperature, salt solution concentration, liquid level and adsorption time. After clicking the start preparation button, the parameters are transmitted to the main controller 14. Step 2, Salt Solution Preparation: The main controller 14 opens the electrically controlled water valve 12, and the clean water in the clean water container 11 is injected into the salt solution preparation container through the water injection pipe 13. The liquid level sensor 20 detects the liquid level in real time. After the preset liquid level is reached, the electrically controlled water valve 12 is closed to stop the injection of clean water. Then, the stirrer 7 is started to stir the salt solution preparation container 6 and the heater 8 is started to heat it. After the temperature sensor 10 detects that the water temperature reaches the preset temperature, the heater 8 is turned off to stop heating. The electrically controlled feeding switch 4 is opened, and the metal salt in the hydrated salt bin 3 enters the salt solution preparation container 6 through the salt addition pipe 18 to realize the addition of the set amount of metal salt to the salt solution preparation container 6. Under the action of stirring, it dissolves. After the salt concentration sensor 9 detects that the salt concentration reaches the preset concentration, the electrically controlled feeding switch 4 is turned off to stop the addition of metal salt, and the initial salt solution preparation is completed. Step 3, Circulating Immersion Adsorption: The main controller 14 starts the water pump 5, and pumps the salt solution in the salt solution preparation container 6 into the preparation container 1 through the water pump 5 and the salt solution injection pipe 16. The solution gradually immerses the target adsorbent 2 in the preparation container 1. When the liquid level in the preparation container 1 is higher than the outlet of the recovery pipe, the solution flows back to the salt solution preparation container 6 through the recovery pipe 17, forming a solution circulation. Step 4: When the preset preparation (adsorption) time is reached, the main controller 14 controls the human-machine interface 15 to provide audio and visual prompts. The operator takes out the target adsorbent 2 from the preparation container 1 and dries it, thus obtaining the finished composite hydrated salt thermal storage material.

[0037] In step 3, the liquid level control is as follows: Liquid level sensor 20 continuously monitors the liquid level in the salt solution container 6. Once it drops below the preset value by more than 1 cm, the main controller 14 opens the electrically controlled water valve 12 to replenish clean water to the salt solution container 6 to the preset liquid level. The reasons for the drop in liquid level include: water absorption by the adsorbent, liquid retention in the pipeline, and a small amount of evaporation. Salt concentration control is as follows: Salt concentration sensor 9 continuously monitors the solution concentration in the salt solution container 6. Once it drops below the preset value by more than 2%, the main controller 14 opens the electrically controlled feeding switch 4 to replenish metal salt to the salt solution container 6 to the preset concentration. The reasons for the drop in concentration include: some salt in the reflux solution has been retained and absorbed by the adsorbent, and the dilution of the solution by the water replenishment operation. Temperature control is as follows: Temperature sensor 10 continuously monitors the solution temperature in the salt solution container 6. Once it drops below the preset value by more than 1°C, the temperature sensor 9 opens the water valve 12 to replenish clean water to the preset value to the preset liquid level. In the above, the main controller 14 turns on the heater 8 to heat the salt solution in the salt solution container 6 to the preset temperature. The reasons for the temperature drop include: ambient heat dissipation, cold water introduced for water replenishment, and room temperature salt introduced for salt replenishment. The cascade coupling relationship of these three closed loops is: water replenishment (liquid level closed loop trigger) → concentration drop → trigger concentration closed loop salt replenishment; salt replenishment → temperature drop → trigger temperature closed loop heating. The three closed loops form a cascade trigger chain, which dynamically maintains the stability of process parameters during the cyclic soaking process and ensures that the salt load in the adsorbent is uniform.

[0038] The three controlled parameters (liquid level, concentration, and temperature) are all related to the specific physicochemical process of the porous adsorbent soaking in the adsorbed salt solution. The closed-loop control of the three parameters does not operate independently, but rather forms a cascade triggering relationship naturally due to the correlation of the physical processes. This application utilizes this relationship to design a collaborative compensation strategy—when the adjustment action of any closed loop causes other parameters to deviate, the corresponding closed loop automatically intervenes to compensate, forming a self-stabilizing regulation. The solution circulates between the preparation container 1 and the salt solution container 6. The sensor in the container reflects the average state of the entire system in real time. The closed-loop control is executed on the container side, and the regulation effect is transmitted to the adsorbent in the preparation container through circulation, realizing the dynamic balance of the entire system.

[0039] Compared with the prior art, the embodiments of this application have the following advantages: (1) It can realize the fully automated preparation of composite hydrated salt thermal storage materials: transforming the manual operation in the laboratory (vacuum impregnation, long-term dripping and stirring) into one-click automatic production. Operators only need to place the adsorbent, set the parameters and take out the finished product, which greatly improves production efficiency and product consistency. (2) Three-loop collaborative control ensures stable product quality: In view of the cascade coupling characteristics of liquid level, salt concentration and temperature during the adsorbent soaking process, a special collaborative control strategy is designed to continuously maintain the stability of process parameters in the dynamic process and ensure that the salt load of different batches of products is consistent. (3) The salt solution is recycled to solve the problem of uneven adsorption: the solution is continuously circulated between the preparation container and the salt solution container, and real-time concentration compensation is used to avoid uneven adsorption caused by local concentration decay of the solution during static soaking, so that the salt distribution inside the adsorbent is more uniform. (4) The salt solution preparation is highly integrated and easy to operate: the preparation, heating, stirring, soaking, circulation and recycling are all integrated into a single device. The human-machine interactive touch interface allows for intuitive parameter setting, reducing the requirements for the professional skills of the operators.

[0040] Specific Case 1: Preparation of Zeolite 13X-supported MgSO4 composite thermal storage material (1) Place blank zeolite 13X particles (i.e. target adsorbent 2) into preparation container 1. The zeolite particles are pre-dried at 150°C for 2 hours to remove adsorbed moisture. (2) Turn on the power supply 19 of the preparation device. After the main controller 14 passes the self-test, the human-machine interface 15 enters the parameter setting interface. (3) Setting parameters: soaking temperature 40℃, salt solution concentration 20wt%, liquid level (based on the scale of the equipped container), adsorption time 2 hours; (4) Click to start preparation, and the system will automatically execute: add water to the preset liquid level → start the stirrer → heat the salt solution to 40°C → open the hopper and add the metal salt of MgSO4 to a concentration of 20wt% → start the water pump to pump the solution into the preparation container to soak the zeolite; (5) During the 2-hour soaking process, the liquid level, salt concentration and temperature control are continuously operated: when the liquid level drops by more than 1 cm, water is automatically replenished; when the salt concentration drops by more than 2% due to water replenishment and adsorption, salt (MgSO4) is automatically replenished; when the temperature drops by more than 1℃ due to water replenishment and salt replenishment, heating is automatically performed. (6) After 2 hours, the preparation device will issue an audio-visual prompt. The operator will take out the zeolite particles and let them air dry or dry them at low temperature to obtain the finished zeolite 13X-MgSO4 composite heat storage material. According to the test, the heat storage density of the material can reach about 600-700kJ / kg, and the deviation of heat storage density between batches is controlled within ±5%.

[0041] Other specific examples: Adjustment of preparation parameters for different salt types and concentrations For different target adsorbent materials (zeolite 4A, zeolite 5A, activated carbon, etc.) and different metal salt types (CaCl2, MgSO4, SrBr2, etc.), the device can automatically adapt by simply adjusting the preset temperature, concentration, and adsorption time on the human-machine interface. For example, if the metal salt solution is CaCl2, the concentration is set to 25wt%, the soaking temperature is 35℃, and the adsorption time is 1.5 hours; if the metal salt solution is MgSO4, the concentration is set to 15wt%, the soaking temperature is 50℃, and the adsorption time is 3 hours.

Claims

1. A device for preparing composite hydrated salt thermal storage materials, characterized in that, The device includes a preparation container and a salt solution preparation container. The preparation container has a top-opening cavity in which a target adsorbent is placed. The target adsorbent is a porous working fluid framework material without metal salt loading, which serves as the carrier framework for the composite hydrated salt thermal storage material. The salt solution preparation container is connected to the top of the cavity via a water pump and a salt solution injection pipe. The salt solution preparation container is used to hold a mixture of water and metal salt. A raw material supply subsystem is installed on the top of the salt solution preparation container. A drain outlet is provided at the bottom of the preparation container. The drain outlet is connected to the salt solution preparation container via a recovery pipe. The liquid is recovered when the outlet of the recovery pipe is below the immersion liquid level of the target adsorbent.

2. The apparatus for preparing composite hydrated salt thermal storage material according to claim 1, characterized in that, The preparation container contains an adsorbent storage rack, in which the adsorbents can be stored. The bottom of the adsorbent storage rack is equipped with support legs, and the top is equipped with a cover plate. A salt solution injection port is located in the middle of the cover plate. The salt solution injection port is connected to a salt solution injection pipe. After the salt solution enters the preparation container, it can soak the adsorbents in the adsorbent storage rack.

3. The apparatus for preparing composite hydrated salt thermal storage material according to claim 2, characterized in that, The adsorbent storage mesh frame includes a bottom double-ring mesh and a middle double-ring mesh. The bottom double-ring mesh includes a bottom sealing plate and a first inner ring mesh cover and a first outer ring mesh cover coaxially arranged on the bottom sealing plate. Support legs are set at the bottom of the bottom double-ring mesh to suspend and support the adsorbent storage mesh frame. The upper ends of the first inner ring mesh cover and the first outer ring mesh cover are respectively provided with a first external thread and a first internal thread. The middle double-ring mesh includes a second inner ring mesh cover and a second outer ring mesh cover. The second inner ring mesh cover and the second outer ring mesh cover are fixedly connected near the bottom by multiple circumferentially evenly arranged spokes. The lower ends of the second inner ring mesh cover and the second outer ring mesh cover are respectively provided with a second internal thread and a second external thread. The upper ends of the second inner ring mesh cover and the second outer ring mesh cover are respectively provided with a third external thread and a third internal thread. An external thread and a first internal thread can be spirally connected to a second internal thread and a second external thread, respectively. The middle section of the double ring mesh is spliced ​​in multiple ways. The second internal thread and the second external thread at the lower end of the upper middle section of the double ring mesh can be spirally connected to the third external thread and the third internal thread at the upper part of the lower middle section of the double ring mesh, respectively. The bottom of the cover plate is provided with a fourth internal thread and a fourth external thread, which can be spirally connected to the third external thread and the third internal thread, respectively. The outer diameter of the cover plate maintains a clearance fit with the inner diameter of the preparation container. After multiple middle section double ring meshes and the bottom double ring mesh are spliced ​​together, a storage cavity is formed between the inner and outer ring meshes. After the target adsorbent is placed into the storage cavity, it is covered with the cover plate. The cover plate is provided with vent holes around its circumference, and the vent holes are located outside the storage cavity.

4. The apparatus for preparing composite hydrated salt thermal storage material according to claim 1, characterized in that, The salt solution is equipped with a container fitted with a stirrer for stirring the solution and a heater for heating the solution.

5. The apparatus for preparing composite hydrated salt thermal storage material according to claim 1 or 4, characterized in that, The raw material supply subsystem includes a hydrated salt silo, an electrically controlled feed switch, a clean water container, and an electrically controlled water valve. The hydrated salt silo is used to store metal salt particles or powder to be loaded. The hydrated salt silo is installed above the salt solution preparation container and is connected to the salt solution preparation container through an electrically controlled feed switch and a salt addition pipeline. The clean water container is connected to the salt solution preparation container through a pump and a water injection pipeline, on which an electrically controlled water valve is installed.

6. The apparatus for preparing composite hydrated salt thermal storage material according to claim 1 or 5, characterized in that, The salt solution container is equipped with a temperature sensor for measuring the solution temperature, a liquid level sensor for measuring the solution level, and a salt concentration sensor for measuring the salt concentration of the solution.

7. The apparatus for preparing composite hydrated salt thermal storage material according to claim 6, characterized in that, Temperature sensors, liquid level sensors, and salt concentration sensors are connected to the main controller, which in turn is connected to the water pump, pump, electrically controlled feed switch, electrically controlled water valve, heater, and agitator.

8. The apparatus for preparing composite hydrated salt thermal storage material according to claim 2, characterized in that, The preparation container is fixedly connected to the left side of the support frame, the salt solution container is fixedly connected to the right side of the support frame, and the hydrated salt silo is fixedly connected to the support frame located above the salt solution container.

9. The preparation method of the composite hydrated salt thermal storage material preparation device according to claim 6, characterized in that, The method includes the following steps: Step 1: Place the target adsorbent into the preparation container and set the required process parameters: immersion solution temperature, salt solution concentration, liquid level, and adsorption time; Step 2, Salt solution preparation: Pour clean water into the container for preparing the salt solution, monitor the liquid level in real time, and stop pouring clean water when the preset liquid level is reached. Then stir and heat the container for preparing the salt solution, and stop heating when the water temperature reaches the preset temperature. Add the set amount of metal salt to the container for preparing the salt solution, and dissolve it under stirring. Stop adding metal salt when the salt concentration reaches the preset concentration. The initial salt solution preparation is complete. Step 3, Circulating Immersion Adsorption: The salt solution in the salt solution preparation container is pumped into the preparation container through the salt solution injection pipe. The solution gradually immerses the target adsorbent in the preparation container. When the liquid level in the preparation container is higher than the outlet of the recovery pipe, the solution flows back to the salt solution preparation container through the recovery pipe, forming a solution circulation. Step 4: After the preset adsorption time is reached, remove the target adsorbent from the preparation container and let it dry to obtain the finished composite hydrated salt thermal storage material.

10. The apparatus for preparing composite hydrated salt thermal storage material according to claim 9, characterized in that, Liquid level control: Continuously monitor the liquid level in the salt solution container. If it falls below the preset value by more than 1 cm, add clean water to the salt solution container to bring it up to the preset level. Salt concentration control: Continuously monitor the concentration of the salt solution in the container. If it falls below the preset value by more than 2%, add metal salt to the salt solution container to bring it up to the preset concentration. Temperature control: Continuously monitor the temperature of the salt solution in the container. If it falls below the preset value by more than 1°C, heat the salt solution in the container to the preset temperature.

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