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《工程热物理学报》2017,(11)
热声发电系统具有高效、可靠、结构简单及外燃等独特优势,在煤层气发电、太阳能发电及工业余热利用等领域应用前景广阔。本文针对用于热声发电的曲柄连杆式换能器,建立了物理模型,讨论了活塞质量、转动惯量及电路负载对换能器阻抗特性的影响,表明固定频率、振幅的压力波驱动下,由于曲柄连杆式换能器行程固定,其阻抗幅值不变,而相位角随负载电阻减小而减小,阻抗实部值相应增大。最后根据换能器阻抗特性,简化模拟了采用曲柄连杆式换能器的行波热声发电系统DeltaEC模型,模拟显示在充气压力3.16 MPa、热源温度650℃时,系统可输出约645.4 W电功(热电效率16.6%),表明此换能器用于大功率、低成本热声发电的优势。本研究为曲柄连杆式换能器与大功率热声热机高效匹配的应用提供了理论基础。 相似文献
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行波热声发动机声功输出特性研究 总被引:1,自引:0,他引:1
行波热声发动机具有效率高、可靠性好及环保等优点.本文分别以氮气和氦气为工质研究了行波热声发动机的声功输出特性.在平均压力为3.0MPa,输入功率为3000W时,氮气为工质获得最大492.3W输出声功,氦气为工质获得最大691.3W的声功.此外还针对两种不同锥度的锥形谐振管发动机的声功输出特性进行了对比研究.研究表明:设计合理的谐振管一方面能够有效降低加热温度,有利于利用低品位热源;另一方面还能有效地降低损失,在相同的加热量下具有更高的压比、更大的输出声功及效率. 相似文献
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《工程热物理学报》2020,(6)
为了提高太阳能热发电站的发电效率,提出了耦合空气轮机、汽轮机及热力塔为一体的太阳能发电系统。在该系统中,吸热器吸收的太阳能加热压气机所压缩的高压空气,多余的热量被储存在储热装置中以在无阳光的时候维持电站正常运转。被加热后的高压空气驱动透平后排入余热锅炉产生蒸汽驱动汽轮机,余热锅炉的排气以及冷却汽轮机凝汽器的空气进入热力塔底部驱动风力涡轮。本文建立了该系统的热力学模型并对系统效率作了计算,计算中对水蒸汽动力循环的参数做了优化。计算结果表明,该系统相比传统的太阳能热电站发电效率明显提高,在环境温度为15℃、空气轮机组透平进口温度为700℃、热力塔高度400 m以上时,空气轮机工作在有回热热效率高的工作模式下,系统循环效率超过了50%,该太阳能电站总的能量转换效率将可达到33%。 相似文献
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本文提出了一种带间冷回热的太阳能燃气轮机与卡林那循环组成的联合循环发电系统,对其热力性能进行了分析,并研究了关键运行参数对热力性能影响。塔式太阳能接收器将经过间冷压缩的压缩空气加热至1000℃用以驱动燃气轮机做功。卡林那循环用以回收燃气余热发电。基于蔡睿贤的比较法,推导出了该系统太阳能热发电效率的简明解析式。结果表明,当燃气轮机入口温度为1000℃时,该系统的(火用)效率和太阳能热发电效率分别可达到29%和27.5%,比太阳能燃气-蒸汽联合循环分别高1.8%和1.6%。该系统的提出,为提高太阳能热发电系统的太阳能热发电效率提供了一种方法,并且对太阳能热发电耗水大的问题提供了一个解决途径。 相似文献
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概述了太阳能热发电技术的发展状况,介绍了用于太阳能热发电的5种聚光系统,包括槽式、碟式、塔式、线性菲涅耳式以及地面接收式。详细阐述了这些聚光系统的光学结构、聚光原理以及聚光器件的设计方法和制作工艺,指出了不同聚光系统在聚光过程中的优缺点。文中的讨论可为太阳能热发电聚光系统的设计提供参考。 相似文献
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Harshal Agarwal Vishnu R. Unni K.T. Akhil N.T. Ravi S. Md. Iqbal R.I. Sujith Bala Pesala 《Applied Acoustics》2016
In the past decade, a variety of thermoacoustic engines (TAEs) were devised to convert thermal energy to acoustic power. In this paper, we optimized the design of a standing wave thermoacoustic generator that can provide high intensity acoustic pressure and convert it into electrical power output using a low cost alternator. Three prototypes of standing wave thermoacoustic generator (TAG) were designed to optimize the overall efficiency. The first prototype of standing wave TAG could produce an acoustic pressure of 0.9 kPa (153 dB) with an input thermal power of 210 W. Further, the maximum heat to electrical conversion efficiency was 0.045% with an input thermal power of 250 W. However, the performance of this system was not fully optimized. The performance of TAE depends upon various parameters including stack position, stack length and resonator length. Hence, a new second prototype of tunable TAG was developed to tune these critical parameters in order to improve the overall efficiency. A compact third prototype of TAG was successfully built with optimized parameters and has been tested. In the improved design, high intensity acoustic pressure of 2.9 kPa (163.5 dB) was observed for the same 210 W input thermal power. The maximum heat to electrical energy conversion efficiency was 0.084% with an input of 250 W which is 87% higher as compared to the first prototype. The major reason for the lower conversion efficiency is due to the low efficiency of the alternator. In future, high efficiency alternator designs can be employed along with careful impedance matching to obtain higher conversion efficiencies. The results described in this paper demonstrate the potential of developing compact portable acoustic power and electricity generators for decentralized power applications. 相似文献
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In this paper, an experimental study of the effect of the resonator shape on the performance of a traveling-wave thermoacoustic engine is presented. Two different resonators were tested in the thermoacoustic-Stirling heat. One resonator is an iso-diameter one, and the other is a tapered one. To have a reasonable comparison reference, we keep the same traveling-wave loop, the same resonant frequency and the same operating pressure. The experiment showed that the resonator shape has significant influence on the global performance of the thermoacoustic-Stirling heat engine. The tapered resonator gives much better performance than the iso-diameter resonator. The tapered resonator system achieved a maximum pressure ratio of about 1.3, a maximum net acoustical power output of about 450 W and a highest thermoacoustic efficiency of about 25%. 相似文献
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热声发动机用加热器的设计与实验验证 总被引:4,自引:0,他引:4
热声发动机利用热声效应将热能转换为机械能,热能由核心部件加热器提供。加热器在热声发动机的能量传递和转化过程中起着举足轻重的作用。针对热声发动机的工作特点,介绍了一种采用时均流对流换热公式进行热声发动机用加热器设计的方法。基于该方法,设计了一种新型热声发动机用电加热器,并应用于自行研制的太型多功能行波热声发动机试验台。设计计算和实验结果表明,该加热器能够充分满足热声发动机的加热要求。本文对以振荡流体为特征的换热器设计具有一定参考价值。 相似文献
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Experimental investigation of a thermoacoustic-Stirling refrigerator driven by a thermoacoustic-Stirling heat engine 总被引:1,自引:0,他引:1
In this paper, a thermally-driven thermoacoustic refrigerator system without any moving part is reported. This refrigeration system consists of a thermoacoustic-Stirling heat engine and a thermoacoustic-Stirling refrigerator; that is, the former is the driving source for the latter. Both the subsystems are designed to operate on traveling-wave mode. In the experiment, it was found that the DC-flows had significant negative effect on the heat engine and the refrigerator. To suppress these DC-flows, two flexible membranes were inserted into the two subsystems and worked very well. Then extensive experiments were made to test the influence of different parameters on refrigeration performance of the whole system. The system has so far achieved a no-load temperature of -65 degrees C, a cooling capacity of about 270 W at -20 degrees C and 405 W at 0 degrees C; in fact, the result showed a good prospect of the refrigeration system in room-temperature cooling such as food refrigeration and air-conditioning. 相似文献
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本文介绍了一台由热声斯特林发动机及其驱动的直线发电机组成的热声斯特林发电系统原理样机.一方面为满足发电机与发动机间体积流率和相位的匹配要求,另一方面为了能在直线发电机活塞处获得较好的压力波与体积流率间相位关系、提高直线发电机的电功输出能力,装置保留了发动机原有的锥形谐振管.初步实验以氦气为工质,在2.5MPa平均压力、64Hz工作频率下,获得了97W的电功.本文还分析了该热声发电系统的效率,得出直线发电机声电转换效率超过了0.8.然而由于谐振管耗散了大量的声功,目前整机的热电转换效率还较低. 相似文献
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长江中下游地区很多建筑没有安装专门的供暖设备,传统的空调采暖增加了建筑能耗。利用太阳能和建筑物自身进行采暖,具有重要的意义和价值。本文提出了一种新型的多孔太阳墙采暖房,其核心部分多孔太阳墙是由多孔陶瓷构成。在晴朗的冬季,对多孔太阳墙采暖房的采暖性能进行了实验研究;研究重点检测了不同外界环境(主要是指太阳辐射照度和环境温度)下,多孔太阳墙采暖房的采暖及储热性能。研究表明:多孔太阳墙采暖房在白天大部分时间都具有较好的采暖效果,且采暖房内的温差较小;同时具有较好的储热性能。以实验测得的武汉地区1月某天的实验数据为例,相比环境温度,当天采暖房内最高温升为19.9℃。在07:00~16:00之间,采暖房的平均温升为11.5℃;在辐射强度较弱的16:00~18:00,采暖房的平均温升为6.6℃。在07:00~18:00之间,采暖房内最大温差为1.37℃,出现在12:40。 相似文献