Multi-source energy supply system design method for gradient utilization of temperature and pressure chemical energy
By designing a multi-source energy supply system that utilizes thermo-pressure chemical energy in a cascade manner, the system optimizes the cascade utilization paths of thermal energy, internal energy, and chemical energy, solving the problems of insufficient power supply and thermal management in multi-source energy systems under high Mach number conditions, and achieving efficient energy utilization.
Patent Information
- Application Number
- CN202511179181.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-22
- Publication Date
- 2026-01-02
AI Technical Summary
In mission environments with high Mach numbers, multi-source energy systems face challenges such as insufficient power supply and difficulty in thermal management. Existing energy recovery schemes fail to effectively identify and classify the energy flow grades of thermal energy, pressure energy, and chemical energy, resulting in inefficient consumption of high-grade thermal energy, insufficient work done by pressure energy, and incomplete conversion of chemical energy, leading to increased losses and decreased energy utilization.
By designing a multi-source energy supply system that utilizes thermo-pressure chemical energy in a cascade manner, the system prioritizes matching high-temperature heat sources with the working fluid with the smallest temperature difference for heat exchange, recovering heat energy step by step; converting the pressure energy of high-pressure gas into mechanical energy through an adiabatic expansion process; and gradually releasing the chemical energy of fuel through a multi-stage conversion path, forming a system topology and realizing the cascade utilization of energy.
This improved the system's output power, heat recovery, and energy utilization, while reducing fuel consumption and increasing the system's energy efficiency.
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Figure CN121257012A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of multi-source energy system comprehensive energy management, and particularly relates to a multi-source energy supply system design method for temperature-pressure-chemical energy gradient utilization. BACKGROUND
[0002] In the task environment under high Mach number working conditions, the multi-source energy system faces two major challenges of insufficient power supply and great difficulty in thermal management. On the one hand, the ramjet power system cannot output shaft power, making it difficult to meet the power supply demand of high-power weapon systems; on the other hand, the high-temperature environment in the tail nozzle area causes thermal fatigue and ablation of the wall material, causing the performance of the tail nozzle to decline or even fail. To solve the above problems, an energy supply system combining a reformer with a turbine and a solid oxide fuel cell (SOFC) is proposed, which aims to recover and utilize the heat energy carried by the high-temperature gas in the tail nozzle area and the waste heat released by the SOFC electrochemical reaction to provide the necessary heat source for the heat sink and endothermic reaction of the reforming system. At the same time, the high-pressure reforming gas is expanded to do work, converting its internal energy into mechanical energy. In addition, the SOFC converts the chemical energy contained in the reforming gas into electrical energy through the electrochemical reaction process, providing continuous and stable power output for the system. In summary, the system recovers the heat energy and other multiple energy sources in the multi-source energy system to improve the system output power and meet the power demand.
[0003] However, existing energy recovery schemes mostly use a single path, making it difficult to simultaneously meet the heat dissipation demand under high heat load and the energy supply demand under high power load. The fundamental reason is that the thermal energy, pressure energy and chemical energy in the multi-source energy system have significantly different energy grades. If the energy flow grade is not effectively identified and utilized, it often leads to problems such as inefficient consumption of high-grade thermal energy, insufficient work of pressure energy, and incomplete conversion of chemical energy, resulting in increased losses and decreased energy utilization rate. Therefore, it is urgent to establish a systematic design method for multi-energy collaboration, which can optimize the energy transfer and conversion process according to the temperature gradient, pressure gradient and chemical energy gradient law, and realize efficient utilization of multi-source energy. SUMMARY
[0004] The purpose of the present application is to provide a multi-source energy supply system design method for temperature-pressure-chemical energy gradient utilization, based on a multi-source energy system for temperature-pressure-chemical energy gradient utilization, for guiding the architectural design of an efficient airborne energy supply system. This method improves system performance by orderly planning the gradient utilization path of thermal energy, internal energy and chemical energy.
[0005] The purpose of the present application is achieved by the following technical solutions:
[0006] A design method for a multi-source energy supply system utilizing thermo-pressure chemical energy in a cascade manner, the method comprising the following steps:
[0007] Step 1: Based on the principle of multi-stage thermal energy utilization, determine the optimal heat exchange sequence between each heat source and the heat sink: prioritize matching high-temperature heat sources with the working fluid with the smallest temperature difference for heat exchange, thereby achieving step-by-step heat recovery. Specifically:
[0008] 1) Prioritize using medium- and high-temperature waste heat sources (such as SOFC exhaust gas, >1000K) to heat medium- and high-temperature working fluids with smaller temperature differences (such as hydrogen-rich gas at approximately 970K).
[0009] 2) The preheated working fluid is then reheated using a high-grade heat source (such as the tail nozzle heat source, approximately 1800K).
[0010] 3) Finally, the residual heat after each stage of cooling is used to preheat the cryogenic liquid fuel and reaction medium (such as liquid kerosene and water) to achieve the gradual release and end-of-pipe recovery of heat.
[0011] By adopting the design logic of prioritizing heat exchange matching with the minimum temperature difference, irreversible heat loss is minimized and thermal energy utilization efficiency is improved.
[0012] Step 2: Based on the principle of pressure cascade utilization, plan the energy extraction path for high-pressure gas:
[0013] For the pressure potential energy of high-pressure gas, the high-grade pressure energy should be converted into mechanical energy in the working device through an adiabatic expansion process. In this process, by reasonably setting the pressure drop ratio and the outlet back pressure, the expanded gas can still reach the necessary pressure and temperature conditions to meet the downstream reaction or storage requirements.
[0014] Step 3: Based on the principle of cascaded release of chemical energy, design a phased conversion pathway for fuel chemical energy:
[0015] The chemical energy of fuels should be released gradually through a multi-stage conversion pathway: first, a chemical reaction process under endothermic conditions should be used to partially convert it into intermediate products (such as hydrogen), and then an electrochemical process should be used to extract it into high-grade energy (such as electrical energy), thus achieving the staged release and utilization of chemical energy. A typical implementation of this principle is "thermochemical reforming combined with electrochemical power generation," but this method is not limited to this pathway.
[0016] Step 4: Integrate the three types of tiered paths to generate the system topology;
[0017] Based on the above design logic, the connection sequence and control nodes between each device are determined to form an energy supply system architecture based on energy cascade utilization.
[0018] Step 5: Performance verification and optimization. Verify the matching between each energy level and the overall energy efficiency index of the system through simulation or experiment.
[0019] The system's output power, heat recovery, fuel consumption rate, and overall energy utilization rate are evaluated under the same fuel input conditions, and compared with traditional architectures that do not employ cascade management to confirm the performance benefits of this method.
[0020] The beneficial effects of this invention are:
[0021] A multi-source energy system based on the cascade utilization of temperature, pressure, and chemical energy is used to guide the architectural design of efficient airborne power supply systems. This method improves system performance by systematically planning the cascade utilization paths of thermal energy, internal energy, and chemical energy; based on the cascade laws of temperature, pressure, and chemical energy, it achieves optimized energy utilization design, optimizes energy transfer and conversion processes, and realizes efficient utilization of multi-source energy. Attached Figure Description
[0022] Figure 1 This is the energy cascade utilization process of the present invention;
[0023] Figure 2 This is an architecture diagram of an energy supply system based on the cascade utilization of energy, incorporating the method of this invention.
[0024] Figure 3 This is a diagram of a traditional energy supply system architecture that does not employ energy cascade utilization.
[0025] Among them: 1-kerosene pump, 2-water storage tank, 3-water pump, 4-reformer, 5-oil-gas turbine, 6-gas storage tank, 7-SOFC, 8, 10-exhaust gas-hydrogen-rich mixed gas heat exchanger, 9, 11-exhaust nozzle heat source-hydrogen-rich mixed gas heat exchanger, 12-exhaust gas-kerosene heat exchanger, 13-exhaust nozzle heat source-kerosene heat exchanger, 14-exhaust gas-water heat exchanger, 15-exhaust nozzle heat source-water heat exchanger, 16-29-three-way valve. Detailed Implementation
[0026] A design method for a multi-source energy supply system utilizing temperature, pressure, and chemical energy in a cascade manner is presented. Based on this system, it guides the architectural design of efficient airborne energy supply systems. This method improves system performance by systematically planning the cascade utilization paths of thermal energy, internal energy, and chemical energy, and enhances the efficiency of the energy supply system by designing heat and pressure sources and cascade utilization paths for chemical energy. The system includes components such as a reformer, turbine, SOFC, and gas storage tank. By effectively utilizing the cascaded utilization of temperature, pressure, and chemical energy, the energy supply system is optimized.
[0027] The following specific embodiments illustrate how to apply the design method described in this invention:
[0028] A design method for a multi-source energy supply system utilizing temperature, pressure, and chemical energy in a cascade manner is proposed, based on the cascade relationship between temperature, pressure, and chemical energy to achieve energy utilization. First, the available energy grade is analyzed:
[0029] like Figure 1 As shown, the system can utilize high-temperature heat sources (such as tail nozzle heat source, about 1800K), medium-temperature heat sources (SOFC tail gas >1000K), chemical energy carriers (kerosene, water, reformed gas mixture) and pressure energy potential (reformed gas pressure up to 2MPa).
[0030] Step 1: Implement the thermal energy cascade design. Based on the principle of multi-stage thermal energy cascade utilization, determine the optimal heat exchange sequence between each heat source and heat sink: prioritize matching the high-temperature heat source with the working fluid to be heated with the smallest temperature difference to achieve step-by-step heat recovery.
[0031] Based on the principle of "prioritizing heat exchange with minimal temperature difference", a heat exchange sequence is established:
[0032] 1. Preliminary preheating of the reformed hydrogen-rich gas using medium- and high-temperature SOFC tail gas (>1000K): Hydrogen-rich gas at approximately 970K is used as the first-stage heat sink, exchanging heat with the high-temperature tail gas from the SOFC (approximately 1073–1273K) in a heat exchanger, thus achieving initial temperature rise of the hydrogen-rich gas. This process prioritizes the recovery of medium-grade waste heat, avoiding heat loss caused by direct heat exchange between the high-temperature tail gas and the low-temperature heat sink.
[0033] 2. The preheated hydrogen-rich gas is reheated using a high-grade tailpipe heat source (approximately 1800K): The hydrogen-rich gas, after initial heating by the SOFC tail gas, is introduced into the tailpipe heat source heat exchange channel for efficient heat exchange with the 1800K high-temperature heat source, further raising its temperature to near the operating temperature required for the SOFC reaction. This ensures that the fuel gas reaches optimal reaction conditions before entering the SOFC. This step embodies the principle of "high-energy heat source driving high-energy demand," maximizing the work-capacity of high-temperature thermal energy.
[0034] 3. Utilizing the SOFC tail gas after staged cooling for end-stage heating of the low-temperature working fluids (kerosene and water): After completing the heat transfer to the hydrogen-rich gas, the SOFC tail gas and tail nozzle heat source, although at a lower temperature, still possess considerable heat exchange capacity. Therefore, they are used sequentially to preheat liquid kerosene and liquid water. First, the kerosene is heated to its vaporization temperature (approximately 500–700 K), and then the cold water is heated to a saturated state under high pressure (approximately 400–500 K). Through this staged heat release design from high to low, high-grade heat is fully utilized in multiple stages, significantly reducing heat exchange losses.
[0035] Step 2: Implement pressure energy utilization design and plan the energy extraction path of high-pressure gas according to the principle of pressure cascade utilization.
[0036] For the pressure potential energy of high-pressure gas, the high-grade pressure energy should be converted into mechanical energy in the working device through an adiabatic expansion process. In this process, by reasonably setting the pressure drop ratio and the outlet back pressure, the expanded gas can still reach the necessary pressure and temperature conditions to meet the downstream reaction or storage requirements.
[0037] After high-pressure hydrogen-rich gas undergoes multi-stage heating, it is adiabatically expanded by a turbine power device, converting its pressure energy into mechanical energy. By adjusting the turbine pressure ratio and back pressure, energy release is achieved, and the safe operation of downstream equipment is ensured.
[0038] Step 3: Perform chemical energy release pathway design. Based on the principle of chemical energy cascade release, design a phased conversion pathway for fuel chemical energy.
[0039] The chemical energy of fuels should be released gradually through a multi-stage conversion pathway: first, a chemical reaction process under endothermic conditions should be used to partially convert it into intermediate products (such as hydrogen), and then an electrochemical process should be used to extract it into high-grade energy (such as electrical energy), thus achieving the staged release and utilization of chemical energy. A typical implementation of this principle is "thermochemical reforming combined with electrochemical power generation," but this method is not limited to this pathway.
[0040] The reforming reaction of kerosene and water serves as the first stage for chemical energy release, while SOFC power generation constitutes the second stage, forming a cascaded conversion chain of "low-grade chemical energy → hydrogen energy → electrical energy." Specifically, in the reformer, hydrocarbon fuels (such as kerosene) and water vapor are converted into hydrogen-rich gas through an endothermic reaction, achieving partial release and conversion of chemical energy. Subsequently, this hydrogen-rich gas is fed into the SOFC, where its chemical energy is directly converted into electrical energy in an electrochemical reaction, completing the efficient extraction of high-grade energy. By setting up two stages—"thermochemical reforming + electrochemical power generation"—the cascaded and controllable release and utilization of chemical energy is achieved.
[0041] Step 4: Integrate the three types of tiered paths to generate the system topology.
[0042] Based on the above design logic, the connection sequence and control nodes (such as the position of the three-way valve) between each device are determined to form an energy supply system architecture based on energy cascade utilization.
[0043] Step 5: Performance verification and optimization. Verify the matching between energy levels and the overall system energy efficiency index through simulation or experimentation.
[0044] Through modeling calculations or experiments, the output power, heat recovery, fuel consumption rate, and overall energy utilization rate of the designed system are verified, and compared with the traditional architecture without cascade management to confirm the performance benefits brought by this method.
[0045] This invention applies a method for the cascaded utilization of thermal energy, internal energy, and chemical energy to the design of practical energy supply system architectures (e.g., Figure 2 ), and system architectures that do not adopt this method (such as Figure 3 In comparison, under the same fuel input, system architecture 1, employing a tiered energy management strategy, demonstrates at least a 1.5% improvement in output power (391.8 kW) compared to traditional architectures 2 and 3. Simultaneously, its recovered heat (1101 kW) is 16% higher than traditional airborne power supply system architectures 2 and 3. System architecture 1, employing multi-tiered collaborative management, achieves an energy utilization rate of 78.5%, at least 1.9% higher than traditional architectures 2 and 3. The proportion of fuel calorific value in the recovered heat is defined as the fuel consumption rate. The results show that the fuel consumption rate of architecture 1 is 45.35%, approximately 16.3% lower than traditional architectures 2 and 3. This verifies the superiority of the multi-source energy system design method utilizing temperature-pressure-chemical energy tiers.
Claims
1. A design method for a multi-source energy supply system utilizing thermo-pressure chemical energy in a cascade manner, characterized in that, Based on the gradient law of temperature, pressure, and chemical energy, energy utilization is achieved, including the following steps: Step 1: Based on the principle of multi-stage thermal energy utilization, determine the optimal heat exchange sequence between each heat source and heat sink: prioritize matching the high-temperature heat source with the working fluid to be heated with the smallest temperature difference to achieve step-by-step heat recovery. Step 2: Based on the principle of pressure cascade utilization, plan the energy extraction path for high-pressure gas; For the pressure potential energy of high-pressure gas, the high-grade pressure energy is converted into mechanical energy in the working device through the adiabatic expansion process; in this process, by reasonably setting the pressure drop ratio and the outlet back pressure, the expanded gas still reaches the necessary pressure and temperature conditions to meet the downstream reaction or storage requirements. Step 3: Based on the principle of cascaded release of chemical energy, design a phased conversion pathway for fuel chemical energy; The chemical energy of fuel is released gradually through a multi-stage conversion pathway: first, it is partially converted into intermediate products through a chemical reaction process under endothermic conditions, and then extracted into high-grade energy through an electrochemical process, thus realizing the staged release and utilization of chemical energy. Step 4: Integrate the three types of tiered paths to generate the system topology; Based on the above design logic, the connection sequence and control nodes between each device are determined to form an energy supply system architecture based on energy cascade utilization. Step 5: Performance verification and optimization. Verify the matching between each energy level and the overall energy efficiency index of the system through simulation or experiment.
2. The design method for a multi-source energy supply system utilizing thermo-pressure chemical energy cascaded according to claim 1, characterized in that, In step 1, the design logic of prioritizing heat exchange matching based on minimizing temperature difference is used to minimize irreversible heat loss and improve thermal energy utilization efficiency, as detailed below: 1) Prioritize the use of medium- and high-temperature waste heat sources for heating medium- and high-temperature working fluids with smaller temperature differences; 2) The preheated working fluid is heated again using a high-grade heat source; 3) Finally, the residual heat after each stage of cooling is used to preheat the cryogenic liquid fuel and the reaction medium, thereby achieving the gradual release and end-of-pipe recovery of heat.
3. The design method for a multi-source energy supply system utilizing thermo-pressure chemical energy cascade according to claim 1, characterized in that, In step 3, the realization form based on the principle of chemical energy cascade release is: thermochemical reforming combined with electrochemical power generation.
4. The design method for a multi-source energy supply system utilizing thermo-pressure chemical energy cascade according to claim 1, characterized in that, In step 5, the output power, heat recovery, fuel consumption rate and overall energy utilization rate of the designed system are verified through modeling calculations or experiments, and compared with the traditional architecture without cascade management to confirm the performance benefits.