Design and analysis of an advanced thermal management system for the solar close observations and proximity experiments spacecraft

In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relationship and functions of the integrated database,the intelligent thermal control system and the efficient liquid cooling system in the ATMS are elaborated upon.For the complex thermal field regulation system and extreme space thermal environment,a modular simulation and thermal field planning method are proposed,and the feasibility of the planning algorithm is verified by numerical simulation.A solar array liquid cooling system is developed,and the system simulation results indicate that the temperatures of the solar arrays meet the requirements as the spacecraft flies by perihelion and aphelion.The advanced thermal management study supports the development of the SCOPE program and provides a reference for the thermal management in other deep-space exploration programs.

Controllable thermal rectification design for buildings based on phase change composites

Phase-change material(PCM)is widely used in thermal management due to their unique thermal behavior.However,related research in thermal rectifier is mainly focused on exploring the principles at the fundamental device level,which results in a gap to real applications.Here,we propose a controllable thermal rectification design towards building applications through the direct adhesion of composite thermal rectification material(TRM)based on PCM and reduced graphene oxide(rGO)aerogel to ordinary concrete walls(CWs).The design is evaluated in detail by combining experiments and finite element analysis.It is found that,TRM can regulate the temperature difference on both sides of the TRM/CWs system by thermal rectification.The difference in two directions reaches to 13.8 K at the heat flow of 80 W/m^(2).In addition,the larger the change of thermal conductivity before and after phase change of TRM is,the more effective it is for regulating temperature difference in two directions.The stated technology has a wide range of applications for the thermal energy control in buildings with specific temperature requirements.

Application of entransy to optimization design of parallel thermal network of thermal control system in spacecraft

For distribution optimization of the flow rate of cold fluid and heat transfer area in the parallel thermal network of the thermal control system in spacecraft,a physical and mathematical model is set up,analyzed and discussed with the entransy theory.It is found that the optimization objective of this problem and the optimization direction of the extremum entransy dissipation principle are consistent in theory.For a two-branch thermal network system,the distributions of the flow rate of the cold fluid and the heat transfer area are optimized by calculating the extremum entransy dissipation with the Newton method.The influential factors of the optimized distributions are also analyzed and discussed.The results show that the main influence factors are the heat transfer rate of the branches and the total heat transfer area.The total flow rate of the cold fluid has a threshold,beyond which further increasing its value brings very little influence on the optimization results.Moreover,the difference between the extremum entransy dissipation principle and the minimum entropy generation principle is also discussed when they are used to analyze the problem in this paper,and the extremum entransy dissipation principle is found to be more suitable.In addition,the Newton method is mathematically efficient to solve the problem,which could accomplish the optimized distribution in a very short time for a ten-branch thermal network system.

Thermal control system of Alpha Magnetic Spectrometer

Since its installation on the International Space Station(ISS)in mid-May 2011,the Alpha Magnetic Spectrometer(AMS)has spent over two years on orbit,fully operational,collecting an enormous amount of data including the temperatures from the on-board 1118 sensors for thermal control.A large database is continuously updated and analyzed to understand the thermal behavior of the experiment in the space environment and its interaction with the ISS.This paper specifies the design,building,analysis and testing of the thermal control system and its various components for an overview of the AMS thermal control system and its space environment.Also given are some examples of analysis and correlation of the space environmental and ISS parameters with the thermal behaviors of various AMS components.

Effects of the thermal environment on the thermal control system of AMS

This paper presents an overview of the AMS thermal control system and its thermal environment on the ISS.We give examples of analysis and correlation of space environmental impacting on the thermal control system of AMS.The most critical factors that affect the thermal environment to AMS are beta angle,attitude of ISS,ISS solar array and ISS radiator positions.The design of a special sandwich structure with embedded heat pipes provides the radiator with higher heat transfer ability for electronics and power crates,and it provides a large heat retaining capacity to balance the frequent changes of the space environment temperatures as well.In cold cases,the thermostatically controlled heaters are working actively to protect AMS.However,sometimes,because of ISS special operations plus extreme beta angle condition,AMS needs to request NASA to adjust the ISS configuration for thermal control.The AMS thermal control system is reliable and stable,which has been verified by its operation on the ISS for more than three years.All the detectors operate normally,the electronics and crates work within their specific temperature limits.

Design and experimental study of thermal control system for AMS cryocoolers

The Alpha Magnetic Spectrometer(AMS) is an instrument for the international scientific experiment,composed of six detectors and 650 micro-electronics.The objective of AMS experiment is to search for dark matter and anti-matter in space.In this paper,the thermal control system for AMS cryocoolers is designed,analyzed and experimentally studied.Using loop heat pipes(LHPs) as the main heat dissipation component,the thermal control system has sufficient heat dissipation capability to prevent the cryocoolers from over temperature(+40℃) in hot environment,meanwhile to ensure temperatures of the cryocoolers higher than their lower limit(-20℃) in cold environment.Experiment results show that the thermal control system for AMS cryocoolers functions stably satisfying design specification.

Guide and control of thermal conduction with isotropic thermodynamic parameters based on a rotary-concentrating device

A rotary-concentrating device for thermal conduction is constructed to control and guide thermal energy transmitting in elastic plates.The designed device has the ability of concentrating for thermal conduction and controlling the processes of thermal diffusion in a plate.The multilayered isotropic material properties of the rotary-concentrating device are derived based on the transformation and rotary medium method and a rotation parameter to control the thermal diffusion process is introduced.The efficiency of the rotary-concentrating device for thermal conduction is verified.Stability of temperature fields in a plate with the rotary-concentrating device is analyzed to study the performance of rotary-concentrating.Numerical examples show that the constructed rotary-concentrating device for thermal conduction can effectively rotate and focus on the thermal energy into the device for a wide range of diffusion temperatures,which can enhance the thermal conduction.Therefore,this study can provide a theoretical support for potential applications in fields of energy harvesting and thermal conduction control.

Experimental Research of Electronic Devices Thermal Control Using Metallic Phase Change Materials

A Phase-change thermal control unit( PTCU) filled with metallic phase change material( PCM) Bismuth alloy for electric devices thermal protection was developed and investigated experimentally. The PTCU filled with PCM was designed and manufactured. Resistance heating components( RCHs) produced 1 W,3 W, 5 W,7W,and 10 W for simulating heat generation of electronic devices. At various heating power levels,the performance of PTCU were tested during heating period and one duty cycle period. The experimental results show that the PTCU delays RCH reaching the maximum operating temperature. Also,a numerical model was developed to enable interpretation of experimental results and to perform parametric studies. The results confirmed that the PTCU is suitable for electric devices thermal control.

SIMULATION IN THERMAL DESIGN FOR ELECTRONIC CONTROL UNIT OF ELECTRONIC UNIT PUMP

The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit （ECU） design. By means of circuit simulation, the thermal design of ECU for electronic unit pump （EUP） fuel system is applied. The power dissipation model of each power component in the ECU is created and simulated. According to the analyses of simulation results, the factors which affect the power dissipation of components are analyzed. Then the ways for reducing the power dissipation of power components are carried out. The power dissipation of power components at different engine state is calculated and analyzed. The maximal power dissipation of each power component in all possible engine state is also carried out based on these simulations. A cooling system is designed based on these studies. The tests show that the maximum total power dissipation of ECU drops from 43.2 W to 33.84 W after these simulations and optimizations. These applications of simulations in thermal design of ECU can greatly increase the quality of the design, save the design cost and shorten design time

Thermally Controllable Break Junctions with High Bandwidths and High Integrabilities

Break junctions are important in generating nanosensors and single molecular devices. The mechanically con- trollable break junction is the most widely used method for a break junction due to its simplicity and stability. However, the bandwidths of traditional devices are limited to about a few hertz. Moreover, when using traditional methods it is hard to allow independent control of more than one junction. Here we propose on-chip thermally controllable break junctions to overcome these challenges. This is verified by using finite element analysis. Adopting microelectromechanical systems produces features of high bandwidth and independent controllability to this new break junction system. The proposed method will have a wide range of applications on on-chip high speed independent controllable and highly integrated single molecule devices.

Temperature Control in a PV-WIND Medical Herb Dryer System

This paper introduces a temperature control technique for a medical herb dryer system. The technique fixes the drying temperature of the medical herbs at 40℃ even in cases of rapidly changing atmospheric conditions. The control of the dryer temperature is achieved through using on/off controller. The designed dryer contains two systems, which are the thermal and electrical systems. The thermal system is designed to heat the drying air by using solar water collector and electric heater. While, the electrical system which contains a photovoltaic (PV)-WIND hybrid system is used to feed the different electrical loads of the dryer system. The control technique is investigated through simulation work by using MATLAB-SIMULINK. The simulation results indicate the high capability of the proposed technique in controlling the drying temperature, even in case of rapidly changing atmospheric conditions.

Experimental Study on Indoor Thermal Stratification in Large Space by under Floor Air Distribution System (UFAD) in Summer

A ventilation method of down-supply up-return has grown popular in large space in recent years for comfort ventilation with low thermal load, especially in China, including gymnasium, factory space, and exhibition hall, etc. The undisturbed flow pattern in the space gives a gradient in temperature, and the vertical thermal stratification appears markedly in large space. The object for this paper is to understand the behaviour of an under floor air distribution system in a ventilated space. The thermal stratification characteristics in a real UFAD experimental space were measured. The effects of different supply conditions on the thermal stratification characteristics are investigated based on the experimental results. The relations between space air stratification and the control parameter is predicted. It can be indicated that there are 4 zones composing the vertical thermal stratification. And different zone has different control parameter.

“三全育人”理念指导下热工控制系统试验与维护课程思政的教学设计与实施

对当前高职院校热工控制系统试验与维护课程的教学现状及问题进行分析。提出了以“厚德强技乐业、电力点亮人生”为思政主线的课程思政总体设计思路,从课程思政教学目标、教学体系、教学方法、教学实施、教学评价5个方面对高职院校热工控制系统试验与维护课程思政教学进行了改革探索。实践结果表明,热工控制系统试验与维护课程思政教学改革取得了良好效果,学生的电力报国情怀培育得以强化,人才培养质量显著提高,毕业生获就业单位广泛好评。

基于ADRC的高精度红外热成像仪温度控制系统设计

为了可以更加精准地控制红外热成像仪温度,设计一种基于ADRC的高精度红外热成像仪温度控制系统;由系统供电模块、探测器驱动模块、模数转换模块、视距估算模块、视频信号处理模块、外部存储模块、以太网传输模块和温度控制模块组成温度控制系统;利用自抗扰控制设计一种单轴控制器,将由时延带来的不确定性建模作为系统综合扰动的一部分,对扩张状态观测器以及总和扰动展开估计,同时在前馈通道对其展开补偿,消除时延对控制器产生的影响,将控制器应用于红外热成像仪温度控制中,获取高精度的红外热成像仪温度控制结果;通过实验分析证明,设计系统的帧频、响应波段、启动时间、供电范围和功耗测试结果分别为55 Hz、11μm、3.4 s、12 VDC和0.56 W,具有良好的红外热成像仪温度控制性能,可以满足提取高质量的红外图像的要求。

利用热网蓄能辅助供热机组调频的控制研究

随着如风电、太阳能等可再生能源的并网,使得火电机组需要进行深度调峰且快速响应调度指令。然而,传统的负荷调节控制方法难以使得机组应对调度指令的频繁变化。火电机组热网包含着大量的管道与热力设备,它们均具有很强的蓄热能力,合理利用其蓄热可在短时间内提升机组负荷响应速度。针对上述问题,对利用热网蓄能辅助供热机组负荷调节进行了研究,并设计了基于调度指令与负荷响应偏差的协调控制系统。仿真结果表明,所设计的协调控制系统能够提高机组负荷响应调度指令的能力,且保证供热压力的稳定。

基于可重构分布式控温的高稳定度热控系统研究

随着光学遥感卫星分辨率的不断提高,光学系统的口径和焦距越来越大,空间光学系统对大面积、高稳定度温度控制的需求越来越突出,而集中控温模式存在热控引线多且走线困难、测温稳定性差等不足,难以满足光学系统大面积高稳定度的控温需求.提出了一种主控加远端的分布式控温系统构架和基于差分比例电阻的高稳定度测温方法,研制了基于分布式的可重构控温系统样机.试验结果表明:系统具有较强的拓展性和自主重构能力,大大提高了热控系统的适应能力,测温稳定性优于±3mK/3h.

基于计算机的蓄热式加热炉燃烧过程控制系统研究

随着工业生产和能源需求的不断增长,工业领域正经历着巨大的变革。在此背景下,热处理和加热炉的设计和操作变得至关重要,因为它们直接影响到生产过程的效率和环境可持续性。蓄热式加热炉是热处理工业中的重要设备,广泛应用于钢铁、有色金属和其他行业。其燃烧过程的控制对产品质量、能源利用效率和环境保护至关重要。对基于计算机的蓄热式加热炉燃烧过程控制系统进行了深入研究和分析。探讨了蓄热式加热炉结构以及特点,分析蓄热式加热炉燃烧控制策略,并从温度前馈双交叉限幅燃烧控制系统设计以及板坏温度预报模型介绍结合了基于计算机控制的蓄热式加热炉设计方法,能够帮助工业企业以应对不断变化的工业需求和环境法规,推动热处理工业的可持续发展。

高导热石墨薄膜真空环境下导热性能测试验证

石墨薄膜具有极佳的导热性,可满足航天器内部高功耗电子设备的散热需求,但由于其易掉渣掉粉及稳定性差而不能直接应用于航天器热控系统。鉴于此,文章提出对石墨薄膜进行封装处理,并对制备出的封装石墨薄膜进行了性能测试,结果表明:石墨薄膜经过封装后解决了掉渣掉粉问题。随后将封装石墨薄膜应用于卫星单机设备,在轨和仿真数据表明:某型号的姿轨控扩展单元单机的最高温度较不使用封装石墨薄膜时下降了7℃,另一型号的应答机单机最高温度下降了8.5℃,达到控温目的。封装后的石墨薄膜适用于航天器设备且具有良好的散热性能。

新能源汽车电池热管理控制系统设计及实现分析

随着全球对环境保护意识的增强和对传统燃油汽车排放污染的担忧,新能源汽车作为一种清洁、高效的交通工具逐渐受到人们的关注和青睐。而作为新能源汽车的核心部件之一,电池的性能和寿命对整个车辆的性能和使用寿命有着重要影响。其中,电池的热管理控制系统是保证电池正常工作和延长电池寿命的关键。文章主要通过对新能源汽车电池热管理控制系统的设计和实现进行分析,以提高新能源汽车电池的性能和寿命。