最新刊期
卷 46 ， 期 3 ， 2025
- 摘要：Heat pump technology has become an essential solution in the field of medium- and low-temperature heating due to its superior efficiency in converting electrical energy into thermal energy. However, owing to the lack of stable heat sources during winter in northern China, it is necessary to store the heat sources within the urban area throughout the seasons to ensure the stability of the heat provided by the heat pump system. In this study, based on the project of seasonal/daily thermal storage of river water in Guantao, a simulation model was constructed using the Transient System Simulation Tool (TRNSYS). A sensitivity analysis of the thermal energy storage unit parameters was conducted under the constraint of the fixed site area. The configurations and strategies of the daily thermal energy storage were optimized. The results show that the temperature rise of the thermal energy storage unit reaches 3.2 ℃ after 10 years of operation, effectively preventing the soil heat imbalance. The distance between the buried pipes and the depth had the greatest influence on the performance of the system. The total length of the pipes could be reduced by approximately 23% with a spacing of 4 m and a depth of 150 m. The daily thermal energy storage system should be matched to the valley power storage heat and heat release load to avoid wasting the valley power. If the storage heat power is large, the volume of the storage tank can be increased, and the flat power heat release is considered. The optimized system improves the utilization rate of valley power and reduces annual operating costs by 11.2%.关键词：seasonal thermal energy storage;river water;peak-valley electricity price;TRNSYS2|0|0更新时间：2025-05-30
- 摘要：Energy storage technology can balance the mismatch between energy supply and demand, which is an important link between the use of renewable energy and waste heat. Absorption thermal energy storage has attracted considerable attention in recent years owing to its high energy-storage density, high energy-storage efficiency, low charging temperature, low heat loss, and flexible output. A state-of-the-art review of advanced cycles, working pairs, and experimental prototypes was conducted. The development of advanced cycles has further improved the energy storage density and efficiency and lowered the charging temperature. The screening of novel working pairs solved the crystallization problem of conventional salt solutions, increased the options of working fluids for different scenarios, and reduced costs. The successful development and operation of experimental prototypes have confirmed the excellent performance of absorption thermal energy storage and paved the way for its promotion and application. In conclusion, the challenges and opportunities of absorption thermal energy storage for the future are summarized, and the development direction is discussed.关键词：absorption thermal energy storage;energy storage density;energy storage efficiency;charging temperature;working pair2|0|0更新时间：2025-05-30
- 摘要：Topological fins can significantly improve heat transfer in latent heat storage units. In this study, a two-dimensional topology optimization model for a shell-and-tube latent heat storage unit was developed and experimentally validated. The optimal fin for different operating conditions and charge-discharge cycles was investigated. Box-counting dimensions and fin surface areas per unit length were used to characterize the topological fins. The results showed that increasing the charging time simplified the fin structures, whereas discharging times of more than 600 s extended the fin tips. For the 3 000 s charge-discharge cycle, the optimal fin increased the surface area per unit length by 80% and the discharge energy density by 37.6% compared to the fin for the 3 000 s charging process. The topological fin for a 300 s discharge-charge cycle with an extended branch resulted in a 7.7% increase in heat storage density.关键词：latent thermal energy storage;topology optimization;fin structure;natural convection;multi-condition optimization2|0|0更新时间：2025-05-30
- 摘要：Solution absorption energy storage is a new energy storage and release technology characterized by high energy storage density, low heat loss, good mobility, and long-term energy storage. Energy storage density and energy storage efficiency are the key indexes for measuring the energy storage capacity of absorption energy storage systems and the key parameters for evaluating the energy conversion efficiency of absorption energy storage systems, respectively. Based on thermodynamic principles, the energy storage characteristics and applicability of absorption energy storage systems were investigated using six types of absorption solutions under different conditions. The results show that both energy storage density and energy storage efficiency increase with an increase in heat source temperature and cooling water temperature and decrease with solution concentration. At a heat source temperature of 70-120 ℃ and condensing temperature of 24-36 ℃, NaOH-H2O has the largest energy storage density and efficiency, CaCl2-H2O has the smallest energy storage density and efficiency, and LiBr-H2O has the widest applicability of temperature range.关键词：absorption;energy storage;energy storage density;energy storage efficiency2|0|0更新时间：2025-05-30
- 摘要：In this study, a phase-change heat-storage water tank with a flat-plate storage plate was designed with phase-change materials. A heat-storage water tank model was constructed using the same staggered arrangement. Experiments and simulations were used to investigate the heat storage and discharge performances of a flat-plate-filled phase-change heat-storage water tank and the influence of the discharge flow rate on the heat release performance of the change materials. The role of different discharge flow rates in improving the heat release performance of phase change materials is discussed. The results show that filling a 98 L water tank with 12.15 L of phase change materials in a flat plate manner increased the heat storage capacity of the water tank by 17.91% while improving the stability of the system operation. By analyzing the flow rates under different heat release modes, it was found that at a discharge flow rate of 100-175 L/h, the heat release ratio of the phase change materials was maintained above 88%. The hot water supply volume reached 135 L. However, the heat transfer between the fluid and the phase change materials was no longer timely when the flow rate increased. The heat release ratio of the phase change materials gradually decreased to 81.5%, and the hot-water supply volume decreased to 125 L. To improve the heat discharge performance of phase change materials in a heat-storage water tank, it is necessary to ensure sufficient external heat transfer conditions and fundamentally improve the heat exchange capacity of the phase change materials.关键词：phase change thermal energy storage system;numerical simulation;heat transfer enhancement;composite phase change materials2|0|0更新时间：2025-05-30
- 摘要：A household photovoltaic intelligent power supply system was proposed to increase the on-site consumption capacity of household photovoltaics and fulfill the requirements for a comfortable and convenient living environment. The system can fulfill the requirements of household electricity, space heating, space cooling, and hot water supply throughout the year. Heating and cooling were realized using air source heat pumps (ASHP), underfloor heating, fan coil units, and energy storage water tanks, which store hot water in winter and cold water in summer. A TRNSYS simulation model of the system was created based on residential buildings in Shandong, China. Based on the simulation results and local electricity prices, the energy storage operation plan was optimized, and the economic efficiency of the system was analyzed. The results indicate that the system can meet the building's year-round electricity consumption, maintain indoor temperatures in winter and summer, and generate revenue from photovoltaic power, yielding the maximum return on investment throughout the entire life cycle. The optimal operating schedule for the ASHP is from 09:00 to 16:00 and 22:00 to 05:00 in winter and from 07:00 to 18:00 and 22:00 to 05:00 in summer. Controllable electrical appliances were used from 10:00 to 16:00. In contrast, appliances with energy storage were used from 11:00 to 14:00 to consume and store the photovoltaic electricity. The energy-storage water tank reduces standard coal consumption by 46% compared to the case without a water tank, demonstrating a substantial energy-saving effect.关键词：household photovoltaic;air-source heat pump;on-site consumption;energy storage2|0|0更新时间：2025-05-30
Energy Storage Technology
- 摘要：Hydrogen energy, as a carbon-free energy source and a pivotal technology for attaining the goals of "carbon peaking and carbon neutrality", has attracted considerable global interest in recent years. The storage of liquid hydrogen offers several advantages owing to its high hydrogen storage density, low storage pressure, and high energy density. However, the industrial development of hydrogen energy still faces many problems. Technologies for large-scale, long-term storage and long-distance transportation are crucial problems in the utilization of liquid hydrogen. Therefore, it is necessary to develop efficient technologies for storing and transporting liquid hydrogen and to build large liquid hydrogen storage tanks with good thermal insulation performance. In this paper, the development status of large liquid hydrogen storage tank storage technology at home and abroad is reviewed, and key problems such as cryogenic insulation and material thermal stress in liquid hydrogen storage are analyzed. The difficulties associated with hydrogen storage and transportation are highlighted, and the development direction of liquid hydrogen storage technology is examined.关键词：liquid hydrogen;storage tank;storage and transportation;insulation;thermal stress2|0|0更新时间：2025-05-30
- 摘要：An electric vertical take-off and landing flying vehicle (eVTOL) is a potential technology for future urban air mobility. A major challenge for thermal management systems is the high cooling requirement and the variable application scenarios. To overcome this challenge, a multi-scene eVTOL-integrated thermal management system was developed. In this study, an eVTOL thermal management simulation platform based on Amesim simulation software was developed to investigate the effects of flight conditions on thermal management and range. The simulation results show that increasing the cruise altitude can reduce the thermal management energy consumption when the ground temperature is high. The maximum reduction of energy consumption for thermal management energy is 4 kW when the cruising temperature ranges from 10 ℃ to 26 ℃. When the hovering rescue duration is more than 150 s during the emergency rescue operation, the temperature difference inside the battery becomes too pronounced. A reduced payload improves the range, with the unloaded range being 1.33 times greater than the fully loaded range.关键词：flying vehicle;electric vertical take-off and landing;thermal management architecture;simulation platform;performance analysis2|0|0更新时间：2025-05-30
- 摘要：A transcritical CO2 heat-pump air-conditioning system has effective heating performance at low temperatures, and the variation of dynamic parameters during operation significantly affects the thermal comfort inside the passenger cabin. To study the comfort of the passenger compartment and the coupling law of the dynamic changes in the parameters of the transcritical CO2 heat-pump air-conditioning system, a joint simulation model was built based on the one-dimensional simulation software GT-Suite and the three-dimensional computational fluid dynamics (CFD) software STAR-CCM+. The three-dimensional cabin model can provide accurate real-time state parameters of the supply and return air for a one-dimensional simulation system of heat-pump air conditioners. The results show that the temperature distribution of the thermal environment of the passenger compartment is relatively non-uniform, necessitating the application of the weighted predicted mean vote (PMV) to evaluate this non-uniformity. In a multi-PID control transcritical CO2 automobile heat pump air conditioning system, a control method based on the weighted PMV comfort model can maintain the regulation and stability of the system's target parameters. Under ambient temperature conditions of 43 ℃ in cooling mode, the control method can reduce the compressor's power consumption by 9.4%. At an ambient temperature of -10 ℃ in heating mode, this method can reduce compressor's the power consumption by 17.9%. This control method can reduce the power consumption of the system compressor while satisfying comfort requirements, constituting a highly efficient energy-saving strategy.关键词：CO2;automotive heat-pump air conditioning;co-simulation;weighted PMV model2|0|0更新时间：2025-05-30
- 摘要：As the power density of lithium-ion batteries continues to increase and high-power fast-charging technologies emerge, the development of battery thermal management systems has become an important and challenging area of research. In this study, a direct-cooling thermal management system for multi-box battery packs using roll-bond cold plates was presented, and the performance of the system was experimentally investigated under different operating conditions. The experimental results show that at a charging rate of 0.5 C and a compressor speed of 2 400 r/min, the average coefficient of performance (COP) of the system can reach 5.83, the maximum dimensionless loss coefficient of the cold plate is 6.27%, and the maximum temperature difference between the cold plates is 1.90 ℃. Notably, the temperature difference between the plates escalates with increasing compressor speed and the thermal load on the cold plate, reaching a maximum value of 3.99 ℃ during the tests. Concurrently, the COP of the system showed a decreasing trend with the compressor speed, reaching a maximum value of 7.41 throughout the duration of the experiments.关键词：thermal management system;Direct cooling;Multi-Box Battery Packs;coefficient of performance2|0|0更新时间：2025-05-30
- 摘要：In this study, the critical snow formation height of a mixed single-aperture nucleator in an artificial snow machine was examined. The threshold values of critical snow formation height were experimentally measured at different air-water pressure ratios and ambient temperatures, and the effects of air-water pressure ratios and ambient temperatures on the threshold values of critical snow formation heights were analyzed. The results showed that the threshold value for the critical height of critical snow formation did not exist at temperatures of -5 ℃ and -10 ℃ under the working conditions with a gas-water pressure ratio of 0.40 MPa∶0.40 MPa, but snow formation could be realized at -15 ℃, and the threshold value for the critical height of critical snow formation was 50-55 cm. When the gas-water pressure ratio is 0.50 MPa∶0.45 MPa or 0.50 MPa∶0.40 MPa, snow can be formed at ambient temperatures of -5 ℃, -10 ℃, and -15 ℃. The gas-water pressure ratio and ambient temperatures have a certain influence on the height of critical snow formation. Under the same ambient temperature, the greater the gas-water pressure ratio, the lower the critical snow height. Provided that the gas-water pressure ratio remains constant, the critical snow height decreases when the ambient temperature lowers from -5 ℃ to -15 ℃, and the trend of the change is more obvious in the temperature interval from -5 ℃ to -10 ℃.关键词：artificial snowmaking;refrigeration system;Critical snow height;operating conditions2|0|0更新时间：2025-05-30
- 摘要：Nucleator nozzles play an important role in promoting the rapid nucleation, crystallization, and snow formation of artificial snow droplets. A visual experimental platform was designed to investigate the gas-liquid two-phase flow process inside the nucleator nozzle and its influence on atomization behavior. The results showed the presence of a two-phase annular flow within the nucleator nozzle and a continuous hollow-cone spray field outside the nucleator nozzle. As the gas-liquid pressure ratio (ΦGL) increases, the interfacial disturbance waves at the gas-liquid interface of the internal flow gradually disappear. As the air core occupied more space, the liquid film thickness gradually decreased and became uniform and stable. This markedly improved the atomization efficiency and quality. When the ΦGL was increased from 20% to 67%, the uniformity and stability of droplet distribution increased by 17% and 60%, respectively. This research offers important guidance for the structural design of high-performance atomized components.关键词：outdoor snowmaker;nucleator nozzle;internal flow pattern;droplet distribution;high-tech Winter Olympics2|0|0更新时间：2025-05-30
- 摘要：As the driving component of a valved linear compressor, the matching relationship between the motor force and gas force directly affects the performance of the compressor. A simulation model of the linear motor was established based on the equivalent gas-force model. In addition, a test bench for the valved linear compressor was constructed to analyze both the simulation and experimental results under various working conditions. This study aimed to investigate the performance of a compressor across different operating scenarios while verifying the reliability of gas force linearization. When the inflation pressure and piston pressure were 0.2 MPa and 5 mm, respectively, the resonance frequency of the experiment and simulation was 50 Hz, and the motor efficiency was 84.3%. The maximum relative errors of the input work, voltage, current, and motor efficiency were 25.8%, 21.7%, 22.7%, and 13.5%, respectively. This indicates that the motor efficiency of the compressor is related to its resonance frequency and that the motor efficiency of the compressor is the highest when the resonance frequency is consistent with the operating frequency. The simulation model of the linear motor is reliable, and the calculation results for the gas load are relatively accurate.关键词：valved linear compressor;linearization of gas forces;linear motors;motor efficiency;resonant frequency2|0|0更新时间：2025-05-30
- 摘要：Improving the energy efficiency of data centers by conserving energy in cooling systems is a priority strategy. In this study, thermal analysis of the prevailing air-water-air cooling system revealed inefficiencies caused by a significant discrepancy in the flow rate between the air and water sides of the server room air conditioning system. To mitigate such discrepancy, a new system architecture with a high-temperature differential on the waterside was proposed. Compared with a conventional system with a small temperature differential, the proposed high-temperature differential cooling system substantially augmented the proportion of natural cooling throughout the year, reduced the energy consumption of pumping fluids, and reduced the total energy consumption of the cooling system by approximately 20%-30%. Although the introduction of a high-temperature differential cooling system requires an increase in the heat exchange area and an increase in the cost of air conditioning for the server room, it concurrently reduces the investment in cooling towers, chillers, circulating pumps, chilled water storage tanks, pipelines, and valves, ultimately reducing the total investment in the cooling system by 15%-25%. Furthermore, the high-temperature differential cooling system facilitates operational adjustments, decouples control from external temperature variations and IT load changes, and minimizes maintenance requirements.关键词：data center;series heat exchange network;flow matching;large temperature difference2|0|0更新时间：2025-05-30
- 摘要：With the development of cold chain Internet of Things (IoT) technology, real-time temperature monitoring and data sharing have become important means to improve the efficiency of chilled meat supply chain management. In this paper, a strategy for optimizing time and temperature coordination based on the cold chain IoT was proposed to improve the operational efficiency of the chilled meat supply chain. Based on predictive microbiology and system reliability theory, this study investigated the effects of time and temperature on the quality of chilled meat. A quality-change model for chilled meat and an energy consumption model for the chilled meat supply chain were developed. To illustrate this approach, a case study of a chilled chicken supply chain was conducted. The findings revealed that there is an optimal level of freshness in the chilled meat supply chain that maximizes the benefits of the supply chain. If the freshness level in one stage deviates from this optimal value, subsequent stages can adjust the time and temperature to achieve maximum supply chain efficiency.关键词：cold chain;Fresh food supply chain;Freshness;Time-Temperature;perishable goods2|0|0更新时间：2025-05-30
- 摘要：To investigate the effect of different drying conditions on the efficacy of a closed heat pump clothing-drying system, parametric studies with control variables were carried out on the circulating air volumetric flow rate, expansion valve opening, and air inlet temperature within the drying chamber and their impact on system heat production, heat pump system coefficient of performance (SCOP), cooling capacity utilization ratio (ER), and exergy loss. The findings indicated that when the expansion valve was set to 70% opening, the circulating air volumetric flow rate was increased from 500 m3/h to 1 000 m3/h, and the heat generation of the system increased by 59.73%. In contrast, the SCOP, ER, and exergy loss decreased by 31.29%, 56.65%, and 31.31%, respectively. Furthermore, when the circulating air volumetric flow rate of 1 000 m3/h was maintained while adjusting the expansion valve opening from 20% to 70%, the heat generation, SCOP, and ER of the system increased by 32.58%, 6.51%, and 29.51%, respectively. At the same time, the exergy loss decreased by 12.44%. Finally, under the conditions of a 70% open expansion valve, a circulating air volumetric flow rate of 1 000 m3/h, and an increase in the desiccator′s air intake temperature from 40 ℃ to 70 ℃, the heat generation of the system increased by 43.71%, while the SCOP, ER, and exergy loss decreased by 11.22%, 60.84%, and 14.17%, respectively. These results emphasize the advantages of reducing the circulating air volumetric flow rate and inlet air temperature within the drying chamber while increasing the expansion valve opening, as these adjustments help to improve the overall performance of the system and promote energy efficiency.关键词：heat pump drying system;system heat production;energy efficiency;cooling capacity utilization ratio;exergy loss2|0|0更新时间：2025-05-30
- 摘要：An experimental platform was built to evaluate the thermal switching performance of a parallel pulsating multi-channel heat pipe using fluoroether HFE-7100 as the working fluid with a liquid filling ratio of 80%. The heating and cooling temperatures of the pulsating heat pipe were controlled using water baths for heating and cooling. The thermal switching characteristics of the pulsating heat pipe at different cooling temperatures were investigated experimentally. The results showed that after the complete start-up of the multi-channel parallel pulsating heat pipe, the average temperature of the evaporation section decreased, the average temperature of the condensation section increased, the thermal resistance decreased, and the heat transfer performance improved rapidly. The temperature and thermal resistance transient processes exhibited a sudden step change, which can be used as a thermal switch. As the cooling temperature increased, the closing time of the thermal switch and the switch temperature increased. At a cooling temperature of 10 ℃, the closing time of the thermal switch was 12 s, and the switch temperature was 59.3 ℃. At higher cooling temperatures, the thermal switch performed better, characterized by a greater increase in the switch ratio and heat transfer rate. When the cooling temperature was 30 ℃, the heat transfer rate increased by 26.8 W following the closure of the thermal switch, with a switch ratio of 5.05.关键词：pulsating heat pipe;thermal switches;switching ratio;cooling temperature2|0|0更新时间：2025-05-30
- 摘要：This study utilizes machine learning techniques to conduct an in-depth analysis of time-series historical data on energy consumption in buildings. A generalized model identification method was developed using an optimization algorithm based on black-box models. The final identification model was determined after optimizing three machine learning methods, including polynomial regression, artificial neural networks, and extreme gradient boosting. A near-zero energy office building in Beijing is the primary focus of this study. Using historical building data and simulation data of the heating system in TRNSYS, load prediction and equipment energy consumption models were established using the developed model identification method. During deployment, the predicted R2 value and total energy consumption deviation were 0.87 and 5.18%, respectively. The results demonstrate that the prediction models established through this method possess high accuracy, providing a reliable basis for subsequent system energy consumption optimization.关键词：model identification;machine learning;TRNSYS;near-zero energy buildings2|0|0更新时间：2025-05-30
- 摘要：Ovarian tissue cryopreservation is an important method for female fertility preservation. Slow freezing of ovarian tissue results in poor follicular survival and low retransplantation efficiency. This study optimized the ovarian tissue cooling procedure by ice seeding, and the effects of ice seeding temperature and cooling rate after seeding on ovarian tissue cryopreservation were analyzed. The programmed cooling apparatus was combined with an ultrasonic device to achieve the ultrasonic seeding of ice crystals, and the ultrasonic intensity was screened. The ovarian survival and histology were assessed after rewarming. The results revealed that the optimized cooling procedure with ice seeding reduced the damage to ovarian tissues. When ice seeding was triggered at -11 ℃ with a cooling rate of 1 ℃/min after nucleation, follicle survival was 88.02%. Ultrasonic nucleation equipment enabled contactless ice seeding of the samples, reducing the risk of contamination and improving the success rate of ice seeding. Furthermore, the follicle survival rate of frozen ovarian tissue increased to 88.38%. The optimization of the procedure and the improvement of the equipment improved the effect of ovarian tissue cryopreservation, reduced the risk of introducing contamination during the cryopreservation process, and provided a new method for the slow cryopreservation of ovarian tissues in clinics.关键词：ovarian tissue;cryopreservation;slow freezing;ultrasonic ice seeding2|0|0更新时间：2025-05-30
- 摘要：Dimethyl sulfoxide (Me2SO) in cell banking exhibits significant side effects on both the cells and the human body. Therefore, an approach that mitigates the side effects of Me2SO with comparable efficacy is urgently needed. The human umbilical cord mesenchymal was used as the research material. First, the thermal physical properties of trehalose, glucose, and L-proline and their regulation of ice crystal growth were measured using a differential scanning calorimeter and a cryomicroscope. Cryopreservation experiments were performed to determine the optimal concentration of each component in the cryopreservation solution, and the viability and functionality of the cells after cryopreservation were validated. The results show that there is no significant difference in cell viability (92.42%±0.28%) and recovery rate (87.80%±4.22%) between the use of the novel stem cell cryopreservation solution (1.25 mol/L ethylene glycol+10 g/L whey protein+0.1 mol/L trehalose+Normosol-R) and the conventional cryopreservation solution (a volume fraction of 10% Me2SO). Moreover, after 3 days of culture, the cell number was (12.42±0.60) × 106 (proliferation fold of 4.97), and the cell phenotype was not significantly different from that of fresh cells. The proposed novel solution for stem cell cryopreservation solves the problem of "Me2SO-free" cryopreservation of cells and offers promising potential for clinical applications.关键词：cryopreservation;cell therapy;mesenchymal stem cells;Me2SO-free;cryopreservation2|0|0更新时间：2025-05-30
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