An energy storage system and control method for micro mobile nuclear power source waste heat utilization

Abstract

The application discloses a kind of energy storage systems and control methods for micro mobile nuclear power source waste heat utilization, system includes integrated in container carrier exhaust gas passage, multiple movable reaction bed and transmission structure;Multiple ladder temperature zones are distributed in the exhaust gas passage along the direction of airflow;The movable reaction bed is loaded with zeolite loaded magnesium sulfate composite medium, and each stage reaction bed is equipped with mass sensor.The application drives the reaction bed to displace in temperature zone by transmission structure, and constructs countercurrent cascade heat exchange field;Control system determines the thermodynamic equilibrium state of medium in the temperature zone according to mass change rate, and drives the reaction bed to change zone dynamically accordingly, realizes that medium traverses different temperature environment in physical space.The application effectively optimizes the consistency of the dehydration degree of heat storage medium, significantly improves the energy storage density of system, and is highly adapted to the mobilization deployment needs of micro nuclear power source.

Description

Technical Field

[0001] This invention relates to the fields of nuclear energy comprehensive utilization and thermochemical energy storage technology, and in particular to an energy storage system and control method for utilizing waste heat from micro mobile nuclear power sources. Background Technology

[0002] With the increasing demand for highly mobile and reliable power in special scenarios such as power supply in remote areas, polar scientific research, front-line positions, and emergency response to sudden disasters, micro mobile nuclear power sources have become an important direction for the development of energy equipment due to their high degree of modularity, support for vehicle-mounted transportation, strong environmental adaptability, and long-term maintenance-free operation.

[0003] Currently, these types of miniature mobile nuclear power plants generally adopt the Open Air Brayton Cycle as the core solution for thermoelectric conversion. This system uses ambient air as the working fluid, eliminating the need for a large cooling water system, resulting in a compact structure and rapid response. However, existing Open Air Brayton Cycle systems face significant challenges in practical applications: First, the exhaust gas temperature at the turbine outlet remains high, and the flow rate is enormous. Directly releasing this high-grade waste heat into the atmosphere would result in significant energy waste, leading to low overall thermoelectric conversion efficiency and relatively high fuel consumption. Second, due to the stringent constraints of mobile power plants on overall equipment size, weight, and space, traditional waste heat recovery methods (such as Organic Rankine Cycle (ORC) bottom circulation and sensible heat storage tanks) are often bulky or excessively heavy, making it difficult to achieve efficient waste heat recovery without sacrificing system mobility.

[0004] In recent years, thermochemical energy storage (TCES) technology has attracted much attention due to its high heat storage density and low long-cycle heat loss. Among them, inorganic hydrated salts, represented by magnesium sulfate hydrate (MgSO4·7H2O), have advantages such as high heat storage density, suitable operating temperature, non-toxicity, and low cost, and are considered ideal media for recovering low- and medium-temperature waste heat. However, existing thermochemical energy storage systems generally adopt a structure that statically fills the energy storage medium in a fixed reaction bed. This traditional structure faces the following technical bottlenecks when dealing with the waste heat recovery of micro-nuclear power plants: The heat transfer and dehydration process is highly uneven: In a stationary reactor, high-temperature exhaust gas penetrates the stationary heat storage material layer unidirectionally from the inlet side, and the gas flow temperature decreases sharply along the axial direction. This results in the heat storage material near the inlet side being in a high-temperature zone for a long time, which is prone to excessive dehydration or structural sintering; while the material far from the inlet side cannot be fully dehydrated and stored due to insufficient heating, resulting in low overall energy storage utilization, difficulty in achieving high-density deep dehydration, and poor mobility in the spatiotemporal decoupling of the heat charging and discharging process.

[0005] Therefore, there is an urgent need in this field to develop a novel thermochemical energy storage system and corresponding control method that can adapt to the space constraints of micro mobile nuclear power sources, have high energy storage density, and achieve deep and uniform recovery of waste heat. Summary of the Invention

[0006] To address the technical problems of existing stationary thermochemical reactors, such as uneven heat transfer along the process, large differences in dehydration levels between the front and rear ends, limited overall thermal storage density, and lack of operational flexibility, this invention aims to provide an energy storage system and control method for utilizing waste heat from micro-mobile nuclear power plants. This invention aims to achieve stepped, deep dehydration of the thermal storage medium through a multi-stage, layered dehydration physical arrangement combined with dynamic zone switching control based on quality monitoring, thereby optimizing the uniformity of the thermal storage dehydration process and the controllability of system operation.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An energy storage system for utilizing waste heat from a micro-mobile nuclear power source includes: a waste gas channel and a multi-stage movable reactor bed and a conveying structure disposed within the waste gas channel. The exhaust gas channel is provided with an exhaust gas inlet for introducing high-temperature exhaust gas from the nuclear power system and an exhaust gas outlet for discharging heat exchange gas. The exhaust gas inlet is connected to the exhaust end of the air turbine of the miniature mobile nuclear power reactor system through an interface pipe. The exhaust gas channel has multiple temperature zones with a stepped temperature decrease distributed along the airflow direction. Each of the movable reaction beds is loaded with a composite thermal storage medium to absorb the heat from the exhaust gas and undergo a dehydration thermal storage reaction. The composite thermal storage medium includes hydrated magnesium sulfate as the main energy storage medium and zeolite molecular sieve as the carrier. The conveying structure is configured to carry the movable reaction beds at each stage and is driven by the control system to perform step-by-step displacement between multiple dehydration temperature zones. Each of the movable reaction beds is equipped with a mass sensor to monitor the real-time mass data of the composite thermal storage medium during the staged dehydration process.

[0008] Furthermore, the displacement direction of the movable reaction bed driven by the conveying structure is arranged in the opposite direction to the airflow direction in the exhaust gas channel, so as to construct a counter-current cascade heat exchange field between the heat storage medium and the exhaust gas.

[0009] Furthermore, the multiple temperature zones within the exhaust gas channel are sequentially divided according to the airflow direction into: a high-temperature deep dehydration zone, a medium-temperature transitional dehydration zone, and a preliminary preheating dehydration zone. This zoned reaction scheme aligns with the staged dehydration characteristics of hydrated magnesium sulfate as the temperature increases, effectively overcoming the shortcomings of traditional fixed-bed systems where excessive dehydration at the inlet dissolves the thermal storage salt, and insufficient dehydration occurs due to excessively low temperatures at the far end. The preliminary preheating dehydration zone is connected to the exhaust gas outlet, and the high-temperature deep dehydration zone is connected to the exhaust gas inlet.

[0010] Furthermore, the waste gas passage is integrated into a standard containerized carrier to accommodate the high mobility and space constraints of mobile nuclear power plants.

[0011] The present invention also provides a control method based on the above-mentioned energy storage system, comprising the following steps: S2: Dehydration status judgment: The control system calculates the rate of change of the instantaneous mass m with time t, dm / dt. When the rate of change of the mass of the movable reaction bed under a specific temperature zone is lower than the preset threshold within a set time period, it is determined that the movable reaction bed has reached the dehydration limit of the current temperature zone. S3: Dynamic zone switching scheduling: When the dehydration limit is reached, the control system drives the conveying structure to move the movable reaction bed against the airflow direction to the adjacent higher temperature zone to continue dehydration and moves the movable reaction bed in the high temperature completely dehydrated zone out of the exhaust gas channel, so that the heat is stored in the composite heat storage medium in the movable reaction bed (2).

[0012] Compared with the prior art, the present invention has the following advantages: 1. A multi-level layered dehydration architecture is adopted to achieve high-density tiered energy storage.

[0013] This invention breaks away from the static model of traditional fixed integrated reaction beds, utilizing a conveying structure to allow the composite thermal storage medium to undergo multi-stage dehydration by traversing temperature regions from low to high. This zoned reaction scheme aligns with the staged dehydration characteristics of hydrated magnesium sulfate as the temperature increases, effectively overcoming the shortcomings of traditional fixed beds where excessive dehydration at the inlet dissolves the thermal storage salt and insufficient dehydration at the far end due to low temperatures. It effectively optimizes the overall uniformity of the dehydration reaction, achieving high-energy-density stepped dehydration energy storage of hydrated magnesium sulfate.

[0014] 2. Highly adaptable to the mobility and space constraints of miniature mobile nuclear power sources This system combines a hierarchical dynamic reaction structure with a containerized carrier, achieving continuous operation while maintaining a highly compact energy storage system. The residence time of each reaction module can be independently controlled, and the continuous and stable step-type movable reaction bed enables efficient thermal energy storage reactions. This not only facilitates the decoupling of the heat storage and release processes in time and space but also meets the special operational requirements of rapid deployment, flexible deployment, and highly mobile scheduling of microreactors. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0016] Figure 1 A schematic diagram of the overall architecture and countercurrent stratified reaction principle of an energy storage system for utilizing waste heat from a micro mobile nuclear power source, provided in an embodiment of the present invention; Figure 2 This is a flowchart of the dynamic zone switching control method based on the rate of change of dehydration quality in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1-Exhaust gas passage; 11-Exhaust gas inlet; 12-Exhaust gas outlet; 2-Mobile reaction bed; 21-Composite thermal storage medium; 22-Mass sensor; 3-Transmission structure. Detailed Implementation

[0018] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0019] like Figure 1 As shown, this embodiment provides an energy storage system for utilizing waste heat from a micro-mobile nuclear power plant. The system is integrated within a standard containerized carrier to adapt to the high mobility and space constraints of mobile nuclear power plants. The main architecture of the system includes a waste gas channel 1, a multi-stage mobile reactor bed 2, and a conveying structure 3.

[0020] The exhaust gas channel 1 naturally forms multiple temperature zones with a stepped decrease in temperature along the axial direction of the exhaust gas flow. The airflow is introduced from the high-temperature exhaust gas inlet 11, undergoes heat exchange along the flow path, and is discharged from the exhaust gas outlet 12. According to the distribution of the temperature gradient, the exhaust gas channel 1 can be sequentially divided into a high-temperature deep dehydration zone, a medium-temperature transitional dehydration zone, and a preliminary preheating dehydration zone.

[0021] Each of the movable reaction beds 2 is an independent modular support unit, uniformly loaded with a composite thermal storage medium 21. In this embodiment, the composite thermal storage medium 21 uses zeolite molecular sieves as a porous support framework, with hydrated magnesium sulfate (initially loaded as MgSO4·7H2O) loaded on its surface. The zeolite molecular sieves provide abundant pore structure and a large specific surface area, optimizing the gas-solid mass transfer efficiency at the reaction interface.

[0022] The conveying structure 3 is located at the bottom of the exhaust gas channel 1, connected to the control system, and carries the movable reaction beds 2 at each stage, allowing them to move in steps between multiple temperature zones. Specifically, the direction of displacement of the movable reaction beds driven by the conveying structure 3 is opposite to the airflow direction within the exhaust gas channel 1.

[0023] In this counter-current stepped heat exchange architecture, the ambient-temperature composite thermal storage medium 21 first enters the preliminary preheating and dehydration zone near the exhaust gas outlet 12, where low-grade exhaust gas removes the weakly bound surface crystal water. It then proceeds to the intermediate-temperature transition dehydration zone for a transitional reaction. Finally, it enters the high-temperature deep dehydration zone near the exhaust gas inlet 11, where deep dehydration is completed using undiminished high-temperature turbine exhaust gas. This process allows the thermal storage medium to traverse temperature gradients step-by-step in physical space, closely matching the reaction characteristics of step-by-step dehydration of hydrated salts, thus achieving high-density stepped energy storage.

[0024] To control the above-mentioned stratified dehydration process, this embodiment also provides a dynamic zone switching scheduling system.

[0025] like Figure 1 and Figure 2 As shown, high-precision mass sensors 22 (such as high-temperature resistant weighing sensors) are installed at the bottom of the bearing positions of each level of the movable reaction bed 2. The specific execution logic of the system control method is as follows: Step S1 (Real-time monitoring): The control system continuously collects the instantaneous mass m of the composite heat storage medium 21 in the corresponding movable reaction bed 2 through the mass sensor 22 at the bottom of each reaction bed.

[0026] Step S2 (Dehydration State Determination): When hydrated magnesium sulfate absorbs heat and loses its water of crystallization, the rate of decrease in its macroscopic mass, accompanied by the removal of water, directly characterizes the transient rate of the chemical reaction. The control system performs differential processing on the real-time acquired mass data to calculate the rate of change of the instantaneous mass m of the composite thermal storage medium 21 with time t, dm / dt.

[0027] When the absolute value of the mass change rate dm / dt of a certain stage of the mobile reaction bed 2 within a specific temperature range is lower than the preset equilibrium threshold within a continuously set time window, the control system determines that the dehydration reaction of the composite heat storage medium 21 in that stage of the mobile reaction bed 2 has reached thermodynamic equilibrium under the enthalpy conditions of the current temperature range. At this time, the mobile reaction bed no longer has the ability to continuously absorb heat and undergo phase change within that temperature range.

[0028] Step S3 (Dynamic Zone Switching): Once the equilibrium state determination is triggered, the control system outputs a drive command to the conveying structure 3, pushing the movable reaction bed 2 in the opposite direction of the airflow into an adjacent, higher-temperature zone. Upon entering the higher-temperature zone, the higher environmental thermodynamic potential energy will disrupt the original equilibrium state, stimulating the composite thermal storage medium 21 to shed its stronger-binding deep-layer crystal water. Once the movable reaction bed 2 at the very front (highest temperature dehydration zone) completes the final stage of equilibrium determination, the drive system removes it from the exhaust gas channel 1 for storage.

[0029] Once all the movable reaction beds 2 inside the container have completed deep dehydration and been removed from the channel, the system is fully loaded. At this point, the exhaust gas pipeline is disconnected, and the vehicle carrying the high-density thermochemical energy storage module can be moved to a target area lacking a heat source to inject water and release heat, thus realizing the consumption of stored waste heat.

Claims

1. An energy storage system for utilizing waste heat from a micro-mobile nuclear power plant, characterized in that, include: The exhaust gas channel (1), the multi-stage movable reaction bed (2), and the conveying structure (3) are all included. The exhaust gas channel (1) is provided with an exhaust gas inlet (11) for introducing high-temperature exhaust gas from the nuclear power system and an exhaust gas outlet (12) for discharging heat exchange gas. The exhaust gas channel (1) has multiple temperature zones with a stepped temperature decrease distributed inside along the gas flow direction. Each of the movable reaction beds (2) is arranged in the exhaust gas channel (1), and each of the movable reaction beds (2) is loaded with a composite heat storage medium (21). The composite heat storage medium (21) includes hydrated magnesium sulfate as the heat storage body and zeolite molecular sieve porous substrate as the carrier. The conveying structure (3) is arranged in the exhaust gas channel (1) and is connected to the control system and driven by the movable reaction bed (2) at each level. The conveying structure (3) drives the movable reaction bed (2) to move sequentially between multiple temperature zones under the control of the control system.

2. The energy storage system for waste heat utilization of a micro-mobile nuclear power plant according to claim 1, characterized in that: The conveying structure (3) drives the displacement direction of the movable reaction bed (2) to be opposite to the airflow direction in the exhaust gas channel (1) in order to construct a counter-current stepped heat exchange field between the heat storage medium and the exhaust gas.

3. The energy storage system for waste heat utilization of a micro-mobile nuclear power plant according to claim 1, characterized in that: Each of the movable reaction beds (2) is equipped with a mass sensor (22) to monitor the real-time mass data of the composite thermal storage medium (21) during the dehydration reaction process.

4. The energy storage system for waste heat utilization of a micro-mobile nuclear power plant according to claim 1, characterized in that: The exhaust gas inlet (11) is connected to the exhaust end of the air turbine of the nuclear power system through a sealed pipeline.

5. The energy storage system for utilizing waste heat from a micro-mobile nuclear power plant according to claim 1, characterized in that, The multiple temperature zones within the exhaust gas channel (1) are sequentially divided according to the airflow direction into: a high-temperature deep dehydration zone, a medium-temperature transitional dehydration zone, and a preliminary preheating dehydration zone; the preliminary preheating dehydration zone is connected to the exhaust gas outlet (12), and the high-temperature deep dehydration zone is connected to the exhaust gas inlet (11).

6. The energy storage system for utilizing waste heat from a micro-mobile nuclear power plant according to claim 1, characterized in that, The exhaust gas channel (1) is integrated into a standard container-type carrier.

7. A control method for an energy storage system for utilizing waste heat from a micro-mobile nuclear power source, based on any one of claims 1 to 6, characterized in that, Includes the following steps: S1: Real-time monitoring: The instantaneous mass m of the composite thermal storage medium (21) is obtained in real time by mass sensors (22) installed in each level of the movable reaction bed (2); S2: Dehydration status judgment: The control system calculates the rate of change of the instantaneous mass m with time t, dm / dt. When the rate of change of the mass of the movable reaction bed (2) in a specific temperature zone is lower than the preset threshold within a set time period, it is determined that the movable reaction bed (2) has reached the dehydration limit of the current temperature zone. S3: Dynamic zone switching: When the dehydration limit is reached, the control system drives the conveying structure (3) to move the movable reaction bed (2) against the airflow direction to the adjacent higher temperature zone to continue dehydration and moves the movable reaction bed (2) in the high temperature completely dehydrated zone out of the exhaust gas channel (1). In this way, the heat is stored in the composite heat storage medium (21) in the movable reaction bed (2).

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