Explore the vast range of titles available.

Thermal control of spaceborne micro-hyperspectral imagers (MHIs) operating in inclined low-Earth orbits (LEOs) presents significant challenges due to the complex and dynamically varying external heat flux, which lacks a stable heat dissipation surface. This study proposes a thermal radiation analysis method capable of rapidly deriving accurate numerical solutions for the thermal radiation characteristics of spacecraft in such orbits. A dedicated thermal control system (TCS) was designed, featuring a radiator oriented towards the +zs plane, which was identified as having stable and low incident heat flux across extreme solar–orbit angle conditions. The system employs efficient thermal pathways, including thermal pads and a flexible graphite thermal ribbon, to transfer heat waste from the imaging module to the radiator, supplemented by electric heaters and multilayer insulation for temperature stability. Steady-state thermal analysis demonstrated excellent temperature uniformity, with gradients below 0.017 °C on critical optics. Subsequent thermo-optical performance analysis revealed that the modulation transfer function (MTF) degradation was maintained below 2% compared to the ideal system. The results confirm the feasibility and effectiveness of the proposed thermal design and analysis methodology in maintaining the stringent thermo-optical performance required for MHIs on inclined-LEO platforms.

The multiple working modes, complex working conditions, frequent changes in external heat flux, and high power consumption of communication satellites all pose great difficulties to their thermal design. This paper mainly describes the design of a thermal control system for high-power communication satellites. Firstly, new efficient heat transfer technologies and thermal control materials for spacecraft are introduced. Secondly, the structure and internal heat source of the satellite are introduced. Thirdly, the external heat fluxes are analyzed, and the position of the heat dissipation surface and extreme conditions are confirmed. Then, a thermal control system is designed around the difficulties of thermal control. With heat pipes, the temperature uniformity of +Y deck, −Y deck, and +Z deck increased by 8 °C, 9.9 °C, and 34.2 °C, respectively. Furthermore, the maximum temperature of the power controller, secondary power supply, bidirectional frequency converter, and solid discharge decreased by 32.5 °C, 22.0 °C, 14.0 °C, and 164 °C, respectively. Finally, a thermal balance test is performed. The test results show that the temperatures of the solid-state power amplifier, on-board computer, power controller, secondary power supply, and bidirectional frequency converter meet the requirements of the thermal control indices. In addition, the temperature of thermal-sensitive components such as batteries and the storage tank also meets the requirements. The thermal design scheme is reasonable and feasible, and the thermal balance test verifies the correctness of the thermal design.

This article focuses on the integrated application of the synergetic approach to enhance the quality of intelligent steam generator control systems.By combining various techniques such as model-based control, adaptive control, and artificial intelligence, an efficient and flexible control system can be developed. Model-based control utilizes mathematical models of steam generators to formulate control algorithms and predict system behavior. Adaptive control enables the system to adapt to changing conditions by adjusting control parameters based on real-time measurements. Artificial intelligence techniques, including neural networks and genetic algorithms, facilitate learning, optimization, and data-driven decision-making processes. The objectives of this research are to investigate the benefits of the synergetic approach in steam generator control, including improved steam generation efficiency, optimized energy consumption, enhanced system stability and reliability, and adaptability to varying operating conditions and disturbances. The findings and conclusions of this study are expected to provide valuable insights for engineers, researchers, and professionals involved in the design and implementation of intelligent steam generator control systems. By integrating the synergetic approach, substantial enhancements in control quality can be achieved, leading to optimal operation and maximum efficiency of power plants.

Abstract According to the characteristics of science payload, an adaptive design is made for the centrifuge thermal control system of standard experiment rack and the thermal control system is optimized due to the constraints of platform resources. Referring to the operating conditions of in-orbit environment, it compares the advantages and disadvantages of vapor compression refrigeration, the Stirling cycle and thermoelectric cooler. Finally, the two-stage thermal control scheme combined air–liquid heat exchanger with thermoelectric cooler is chose. In consideration of the actual condition in orbit, a ground mirror-image experiment platform is built to carry out the thermal performance experiments of thermal control system under variable working conditions, such as different science payload heat load, different temperature of liquid supply on platform, and voltage change of thermoelectric cooling component. By means of experimental research, it verifies the rationality of the thermal control system and obtains the thermal control parameters status under the in-orbit condition, which improves the safety and reliability of the system. Once the experiment rack is launched with Space Station in the future, the space-ground comparison between the in-orbit equipment and the ground mirror-image experimental platform will provide more data reference for the study of the influence of microgravity.

Stringent requirements for high fuel economy and energy efficiency mandate using increasingly complex vehicle thermal systems in most types of electrified vehicles (xEVs). Enabling the maximum benefits of such complex thermal systems under the full envelope of their operating modes demands designing complex thermal control systems. This is becoming one of the most challenging problems for electrified vehicles. Typically, the thermal systems of such vehicles have several modes of operation, constituting nonlinear multiple-input/multiple-output (MIMO) dynamic systems that cannot be efficiently controlled using classical or rule based strategies. This paper covers the different steps towards the design of a model-based control (MBC) strategy that can improve the overall performance of xEV thermal control systems. To achieve the above objective, the latter MBC strategy is applied to control cooling of the cabin and high voltage battery. First, a plant model representative of a real vehicle thermal dynamics is developed in Amesim®1D Software. In order to design the model-based controller, the plant model is then utilized to obtain a linear mathematical model using system identification methods. In virtue of its suitability for multivariable systems and its low computational cost, the Linear-Quadratic-Gaussian (LQG) controller is utilized to meet energy efficiency and regulation performance objectives. The robustness against the external disturbances as well as structural uncertainties is demonstrated through rigorous simulations for the considered approach.

Scientific experimental racks are an indispensable supporter in space stations for experiments with regard to meeting different temperature and humidity requirements. The diversity of experiments brings enormous challenges to the thermal control system of racks. This paper presents an indirect coupling thermal control single-phase fluid loop system for scientific experimental racks, along with fuzzy incremental control strategies. A dynamic model of the thermal control system is built, and three control strategies for it, with different inputs and outputs, are simulated. A comparison of the calculated results showed that pump speed and outlet temperature of the cold plate branch are, respectively, the best choice for the control variable and controlled variable in the controller. It showed that an indirect coupling thermal control fluid loop system with a fuzzy incremental controller is feasible for the thermal control of scientific experimental racks in space stations.

One of the key problems in the design of nanosatellites is to provide a specified temperature range for the operation of electronic equipment. In structures of modern nanosatellites mainly used the elemental base of smartphones. To process a large amount of information, more advanced processors with high thermal power are required. The specified thermal mode of the on-board computer can be achieved using a remote heat removal system or by direct contact of the processor cover with the carbon fiber reinforced plastics (CFRP) body of the nanosatellite. Using a model of nanosatellite as an example, a thermal control system with miniature loop heat pipes and highly heat-conducting refrigerators-emitters is designed. The influence of the thermal conductivity coefficient in the reinforcement plane of the nanosatellite CFRP body on its temperature state in low Earth orbit is studied.

In the present work, the phase change energy storage heat exchanger in thermal control system of short-time and periodic working satellite payloads is taken as the research object. Under the condition of constant heated power of the satellite payload, the heat transfer characteristics of phase change energy storage heat exchanger are analyzed by numerical simulation and experimental method. The heat exchanger with fin arrays to enhance heat transfer is filled with tetradecane, whose density varies with temperature. The flow field distribution, the solid-liquid distribution, the temperature distribution, and the phase change process in the plate phase change energy storage heat exchanger unit are analyzed. The flow and heat transfer characteristics of heat exchangers under different fluid-flow rates and temperature were investigated. nema

Effective thermal management is essential for ensuring the safety, performance, and longevity of lithium-ion batteries across diverse applications, from electric vehicles to energy storage systems. This paper presents a thorough review of thermal management strategies, emphasizing recent advancements and future prospects. The analysis begins with an evaluation of industry-standard practices and their limitations, followed by a detailed examination of single-phase and multi-phase cooling approaches. Successful implementations and challenges are discussed through relevant examples. The exploration extends to innovative materials and structures that augment thermal efficiency, along with advanced sensors and thermal control systems for real-time monitoring. The paper addresses strategies for mitigating the risks of overheating and propagation. Furthermore, it highlights the significance of advanced models and numerical simulations in comprehending long-term thermal degradation. The integration of machine learning algorithms is explored to enhance precision in detecting and predicting thermal issues. The review concludes with an analysis of challenges and solutions in thermal management under extreme conditions, including ultra-fast charging and low temperatures. In summary, this comprehensive review offers insights into current and future strategies for lithium-ion battery thermal management, with a dedicated focus on improving the safety, performance, and durability of these vital energy sources.

During operation, lithium-ion batteries generate a significant amount of heat, leading to increased temperature and temperature gradients within the battery cluster. These conditions significantly impair the durability and safety of batteries, underscoring the necessity for a stable heat dissipation system to maintain optimal battery temperatures. The present work introduces a cost-efficient, passive heat dissipation system that integrates prismatic lithium-ion batteries with phase change material (PCM) components. Findings demonstrate that the PCM components effectively lower the highest temperature and reduce the largest temperature variation observed at the end of the discharge process, highlighting their exceptional thermal storage and regulation properties. Moreover, the impact of critical PCM design factors—such as thermal conductivity, melting temperature, and latent heat capacity—on the system’s thermal performance was analyzed. The research offers foundational insights and practical recommendations for designing and deploying passive, economical battery thermal management systems that leverage PCM technology.