汤姆逊效应对热电发电机驱动热电制冷机装置性能的影响

建立了包含汤姆逊效应的热电发电机驱动热电制冷机(TEG-TEC)装置热力学模型,运用非平衡热力学理论和数值计算方法进行了性能分析,对比考虑和不考虑汤姆逊效应2种情况,分析了汤姆逊效应对装置性能的影响。结果表明,汤姆逊效应使TEG-TEC装置性能降低,且降低幅度随热电发电机高温热源温度或制冷空间温度升高而减小。当热电发电机热节点温度和热电制冷机冷节点温度分别取450K和285K,热电单元比取0.5时,汤姆逊效应使制冷率降低29.98%,使制冷系数降低23.02%,使极限制冷温差降低11.35%。考虑到汤姆逊效应的影响,应当将有限数量的热电单元适当多地分配到热电发电机中。文中结论为实际TEG-TEC装置的设计和运行提供了理论指导。     

太阳能半导体冰箱实验研究与性能分析

该文提出一种太阳能半导体冰箱并进行了实验研究与性能分析，它依靠太阳电池驱动，通过热电制冷效应制冷。实验表明，该装置能够维持冰箱内温度在5-10℃，COP约0.3。冰箱性能与太阳辐射和热电制冷元件冷热端温差等条件有很大关系，存在分别使COP和制冷量达到最大值的最佳太阳辐照度。该冰箱可用于边远地区或户外郊游、甚查及施工等缺电条件下食品和饮料的冷藏保鲜以及医用疫苗的保管等。     

热电热泵干衣机的研制及实验研究

热电制冷因为制冷效率较低，难以在一般民用建筑空调／制冷领域推广，但热电热泵相对于直接电加热形式，则不失为一种节能形式。研制了热电热泵干衣机样机，分别针对不同工况进行了系统的实验测试；依据测试数据作了性能分析，指出了进一步优化样机的方向。热电热泵干衣机与普通电干衣机比较，可节省电耗35％左右，具有节能、安静、安全、便利等优势。     

应用溴化锂制冷技术发展热电冷联合生产

对低位热能作为采暖空调的动力─—吸收式制冷的机理、特点、效益等作了简略的介绍，认为溴化锂吸收式制冷技术是实现城市热电冷三联供的有效途径，热电冷联合生产是节电、节能、节省投资、减少环境污染的最佳方法。     

水冷式小空间热电制冷器结构设计与性能分析

基于一种不依赖模块规格型号和换热设备几何参数的热电制冷系统分析方法,建立了热电制冷装置有限时间热力学分析模型。针对水冷式小空间热电制冷器的基本结构,构建了一个由8个商用热电制冷片组成的小型热电制冷器,分析了工作电流、填充系数等对制冷性能的影响,与空冷式热电制冷器性能进行了比较,分析了传热条件对装置性能的影响,所得结果可为水冷式小空间热电制冷器的设计与运行提供参考。     

新型太阳能热电空调的研究

将太阳能薄膜电池与建筑采光相结合，作为家用空调的辅助能量设备，实现建筑节能，介绍了热电空调器的结构和工作原理。给出热电制冷的性能分析和最佳的制冷系数工况，以及风机的耗能情况，计算了使用太阳能热电空调的节电效果。     

热电冷三联产的经济分析

本文简要介绍了热电冷三联产的基本生产工艺，通过对采用溴化锂制冷和中央空调以电制冷两种制冷方式的投资及运行费用进行比较，提出了发展热电冷三联产的良好前景的结论。     

不可逆半导体固态热离子制冷器性能分析和优化

建立了考虑外部有限速率传热过程和热源间热漏的不可逆半导体固态热离子制冷器模型,基于非平衡热力学和有限时间热力学理论导出了热离子制冷器的制冷率和制冷系数的表达式;对比分析了不可逆热离子制冷器与可逆热离子制冷器的发射电流密度特性、电极温度特性以及制冷系数特性;研究了不可逆系统的制冷率与制冷系数最优性能,得到了制冷率和制冷系数的最优运行区间;通过数值计算,详细讨论了外部传热以及内部导热、热源间热漏损失、热源温度、外加电压、半导体材料势垒等设计参数对热离子装置性能的影响。在总传热面积一定的条件下,进一步优化了高、低温侧换热器的面积分配以获得最佳的制冷率和制冷系数特性。结果表明,由于存在内部和外部的不可逆性,热离子装置的发射电流密度及制冷系数都会明显降低;不可逆半导体固态热离子制冷器的制冷率与制冷系数特性呈扭叶型;合理地选外加电压、势垒等参数,可以使制冷器设计于最大制冷率或最大制冷系数的状态。     

热电(冷)联产系统的优化性能

依据有限时间热力学原理导出了不可逆热电联产和热电(冷)联产系统在系统最大火用输出时的基本优化关系,确定了热电(冷)联产系统优化参数和优化构形选取范围,得到了供热(制冷)和发电间的匹配优化特性,通过数值算例得出不同参数对系统性能影响的规律。所得结论可为热电(冷)联产系统的优化设计和最佳工况选择等提供理论依据。     

氧化钛基半导体热电材料的研究进展

热电材料—即实现热能和电能之间直接相互转换的一类功能材料,提供了一种制冷或发电的新方法—在解决能源和环境危机问题上正在扮演越来越重要的角色。传统的三维材料中,由于几个决定热电性能的关键物理参数相互关联,使得现有热电材料很难获得较高热电优值（ZT）。金属氧化物热电材料由于其良好的耐高温性能,是中高温区使用的理想候选者。如果能提高氧化钛基化合物的热电优值,那么氧化钛基化合物将是一类非常优秀的热电材料,因为其不仅具有优良的化学稳定性和热稳定性,而且原材料丰富、不含有毒元素以及制备工艺简单。纳米化能显著降低材料的热导率,是最近二十年提高热电性能的一条主要途径。同时,通过界面和化学组成调控增加与电学性能相关的功率因子也是一种继续提高热电性能的重要方法。本文综述了我们近期对氧化钛基热电材料的研究成果,包括对钛酸盐纳米管较大赛贝克（Seebeck）系数的实验发现,提出利用一维纳米材料独特的空心结构和纳米管层状特殊构造,将两个相关联的物理参数（热导率和电导率）分别调控;通过合成氧化钛基纳米复合材料,研究界面对载流子和声子散射的作用,提出通过载流子能量过滤效应提高其热电性能;采用尿素燃烧法和高温烧结等方法合成具有纳米结构和化学组成调控的氧化钛基化合物,认识化学组成以及界面对声电输运的作用规律;最后介绍能显著提高热电材料功率因子的载流子非对称迁移的理论。     

Transient cooling of thermoelectric coolers and its applications for microdevices

If a current pulse with a magnitude several times higher than the steady state optimum current is applied to a thermoelectric cooler, an instantaneously lower temperature than that reachable at the steady state can be obtained. Most previous studies of this transient cooling effect focus on the minimum temperature achievable for free standing thermoelectric (TE) elements. In this work, we systematically study the transient response of thermoelectric coolers with and without mass loads through examination of both the minimum temperature reached and the time constants involved in the cooling and the recovering stages. For integrated thermoelectric cooler-passive mass load systems, two distinguishable cooling regimes, uniform cooling and interfacial cooling, are identified, and the criterion for utilization of the transient cooling effect is established based on the time constants. Although the results of this work are generally applicable, the discussions are geared towards cooling of microdevices that are of current interests.     

A numerical study on the performance of miniature thermoelectric cooler affected by Thomson effect

Miniature thermoelectric cooler (TEC) has been considered as a promising device to achieve effective cooling in microprocessors and other small-scale equipments. To understand the performances of miniature thermoelectric coolers, three different thermoelectric cooling modules are analyzed through a three-dimensional numerical simulation. Particular attention is paid to the influence of scaling effect and Thomson effect on the cooling performance. Two different temperature differences of 0 and 10 K between the top and the bottom copper interconnectors are taken into account. In addition, three different modules of TEC, consisting of 8, 20 and 40 pairs of TEC, are investigated where a single TEC length decreases from 500 to 100 μm with the condition of fixed ratio of cross-sectional area to length. It is observed that when the number of pairs of TEC in a module is increased from 8 to 40, the cooling power of the module grows drastically, revealing that the miniature TEC is a desirable route to achieve thermoelectric cooling with high performance. The obtained results also suggest that the cooling power of a thermoelectric cooling module with Thomson effect can be improved by a factor of 5-7%, and the higher the number of pairs of TEC, the better the improvement of the Thomson effect on the cooling power.     

Experimental and analytical study on thermoelectric self cooling of devices

This paper presents and studies the novel concept of thermoelectric self cooling, which can be introduced as the cooling and temperature control of a device using thermoelectric technology without electricity consumption.For this study, it is designed a device endowed with an internal heat source. Subsequently, a commonly used cooling system is attached to the device and the thermal performance is statistically assessed. Afterwards, it is developed and studied a thermoelectric self cooling system appropriate for the device.Experimental and analytical results show that the thermal resistance between the heat source and the environment reduced by 25-30% when the thermoelectric self cooling system is installed, and indicates the promising applicability of this technology to devices that generate large amounts of heat, such as electrical power converters, transformers and control systems. Likewise, it was statistically proved that the thermoelectric self cooling system leads to significant reductions in the temperature difference between the heat source and the environment, and, what is more, this reduction increases as the heat flow generated by the heat source increases, which makes evident the fact that thermoelectric self cooling systems work as temperature controllers.     

Optimum selection (design) of thermoelectric modules for large capacity heat pump applications

Thermoelectric modules should be selected or designed to meet the specific cooling/heating requirements of a particular application and in most cases, the cooling/heating capacity and the working temperatures (hot and cold side temperature of thermoelectric devices) are known. Computer modelling can be used to assist the selection process by determining the relationships between the cooling/heating requirements and optimum thermoelectric parameters thermoelectric modules suited to large capacity thermoelectric heat pump applications. Copyright © 2004 John Wiley & Sons, Ltd.     

Liquid cooling in the mini-rectangular fin heat sink with and without thermoelectric for CPU

In the present study, the liquid cooling in the mini-rectangular fin heat sink with and without thermoelectric for CPU is studied. Six mini-rectangular fin heat sinks with two different material types and three different channel widths are fabricated from the copper or aluminum with the length, the width and the base thickness of 37, 37, 5 mm, respectively. The de-ionized water is used as coolant. Effects of channel width, coolant flow rate, material type of heat sink and run condition of PC on the CPU temperature are considered. The liquid cooling in mini-rectangular fin heat sink with thermoelectric is compared with the other cooling techniques. The thermoelectric has a significant effect on the CPU cooling of PC. However, energy consumption is also increased. The results of this study are expected to lead to guidelines that will allow the design of the cooling system with improved heat transfer performance of the electronic equipments.     

半透明晶体硅光伏热电制冷辐射窗的性能分析

针对一种新型半透明光伏-热电制冷辐射窗（STPV-TE-RCW）,通过实验和数值模拟方法对其热电性能进行研究,建立STPV-TE-RCW计算模型,验证其准确性,并针对STPV-TE-RCW中的热电模块不同排列形式、辐射板尺寸、散热形式等进行优化分析。在考虑结构自身发电量与耗电量关系的基础上,通过分析制冷系统COP和耗电量,认为5块热电片串联2个支路并联的热电模块排列形式,高度为1 m的辐射板尺寸和强制对流的散热形式效果更好,在这种情况下,STPV-TE-RCW的耗电量与发电量之比为0.83,制冷量能承担该结构产生的60%冷负荷,辐射铝板提供的制冷量为63.4 W/m²,热电模块的COP为1.41。     

Experimental investigation on controlled cooling by coupling of thermoelectric and an air impinging jet for CPU

In this study, experimental tests have been carried out on the coupling thermoelectric cooling module with minichannel heatsink subjected to impinging airflow for cooling desktop central processing unit (CPU). A controlled thermoelectric-forced test system was designed for this purpose. This was designed using electronic Arduino card. The proposed hybrid cooling system was compared with the conventional forced air-cooling technique. Three power of heat source (CPU) were adopted, investigated, and compared, namely 60, 87, and 95 W. Performance of controlled thermoelectric cooling with three preset temperature were experimentally examined. The effects of air velocity and thermoelectric input current on the case temperature (T_case), thermal resistance, and heat transfer coefficient were analyzed. Results showed that the T_case increases with the increase of its input power. In addition, increasing air jet velocity and thermoelectric input current improve CPU cooling significantly. For a CPU power of 95 W, the recorded T_case temperature was 57°C with the conventional system. While it was maintained below 50°C in the hybrid system. The thermoelectric cooler has had a major effect on CPU cooling, having 15% improvement over conventional forced air-cooling. However, this was accompanied by an increase in energy consumption in the range of 45 W.     

转炉半导体温差发电系统结构设计及数值模拟

设计了一种回收工业转炉余热的半导体温差发电装置。针对转炉转动的特点，研究设计了风冷式的冷端结构。采用Fluent软件对温度分布及速度分布进行了数值模拟，并对计算结果进行了分析。结果表明，采用风扇顸部冲击冷却的形式可达到良好的效果，可使温差发电元件两端温差高达70℃，满足了半导体温差发电温差基本要求，该设计也满足自带风扇负载的要求。     

Experimental study and analysis on novel thermo-electric cooler driven by solar photovoltaic system

Experimental study and analysis on thermoelectric cooler driven by solar photovoltaic system has been carried out. Here the research attention is on testing of system performance under solar insolation. Experimental results revealed that unit could maintain the temperature in the cooler at 10–15°C and have a coefficient of performance (COP) of about 0.34. Analysis of thermoelectric cooling system has been conducted on the basis of COP, cooling capacity and environmental issues. Further investigations verified that the performance of the system is a function of solar insolation rate and temperature difference of hot and cold sides of thermoelectric module etc. There subsist most favorable solar insolation rate which allows COP and cooling production to be maximum value respectively. It is anticipated that the cooler would have prospective for cold storage of vaccine, food and drink in remote and rural areas or outdoor conditions where electricity is not available.     

Numerical simulation of porous latent heat thermal energy storage for thermoelectric cooling

Porous latent heat thermal energy storage for thermoelectric cooling is simulated via a matrix-based enthalpy formulation, having the temperature as unknown, in a three-dimensional domain. The system is made up of two aluminum containers; the inner one contains the cooling objective in water suspension and the outer one the phase change material (PCM) in a porous aluminum matrix. The system’s charging and discharging processes are simulated for constant thermoelectric module cold side temperature under different porosities of the aluminum matrix. The mathematical modeling approach simplifies the analysis while the metal matrix in the PCM greatly improves performance. A direct application of the studied system is vaccine conservation in solar powered thermoelectric cooling systems.