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1.
建立了半导体温差发电器件的基本模型;从稳态的热传导方程出发,对发电器件进行了热力学分析,推导出P型和N型半导体内部的温度分布函数及输出功率和发电效率的表达式;测定了一种Bi-Te-Sb-Se半导体热电材料在低温下的塞贝克系数随温度的变化关系,绘制了曲线并进行数值拟合;结果表明,该种半导体热电材料在低温下性能不佳,需改进配方或生产工艺方可使用。  相似文献   

2.
应用非平衡态热力学和有限时间热力学理论,导出了半导体温差发电器输出功率和效率的一般表达式;兼顾输出功率和效率,给出了半导体温差发电器优化性能的热力学准则;分析了效率随塞贝克系数与汤姆孙系数之比的变化,指出塞贝克系数与汤姆孙系数之比是半导体温差发电器的一个重要性能参数.  相似文献   

3.
汽车尾气温差发电的实验研究   总被引:3,自引:0,他引:3  
为了提高汽车燃油效率以优化能源利用和保护环境,进行了利用汽车尾气废热进行温差发电的实验。搭建测试平台,进行了一系列测试,获得了在不同热端温度(83~270℃)、不同负载(0~520Ω)下单个半导体温差发电器件的输出功率。设计了一种将该器件用于汽车尾气的温差发电的方案。以东风EQ140-1货车为例的经济性分析结果表明:在假设每天行驶12 h、每年行驶330 d、且柴油价格为5元/L的条件下,半导体温差发电系统需8.2 a来回收成本。  相似文献   

4.
利用热电材料实现温差发电技术已成为目前研究热点,但温差发电阵列热端温度分布不均将严重影响系统的输出功率和可靠性。为此,首先针对2×2温差发电阵列,研究其在不同热端温度分布情况下,温差发电阵列内部的连接方式与输出功率和可靠性的关系。其次,提出了一种温差阵列内部连接结构优化方法,通过改变内部连接方式以减少阵列功率损失,提高其可靠性。最后,通过温差实验平台,在不均匀温度下开展了4×4温差发电阵列实验,并与传统串并联阵列、网状阵列和桥型阵列等温差发电阵列进行了输出功率及可靠性比较分析。实验结果表明:在热端温度不一致的情况下,所提出的优化温差发电阵列比传统温差发电阵列可以更好地兼顾温差发电阵列的输出功率与可靠性。  相似文献   

5.
基于自行搭建的温差发电系统性能测试平台,以温度、开路电压、内阻、最大输出功率作为性能参数,研究接触压力对温差发电系统性能的影响规律.研究结果表明:在温差发电系统冷、热端温度均相同的情况下,接触压力增大,则系统开路电压和最大输出功率增大,但增大的幅度随压力的增大而逐渐减小;在温度一定的情况下,接触压力的大小对温差发电片内部的接触电阻影响不大;接触压力对温差发电系统冷、热端温度的瞬态响应特性影响不大,但对系统开路电压的瞬态响应特性影响很大,接触压力增大,则开路电压的瞬态响应速率加快.研究结果证明接触压力对温差发电系统的性能具有显著的影响.  相似文献   

6.
实验测试了单片半导体温差片、双片串联和双片并联温差组件的输出电性能.结果表明:随着热端和冷端的温差增大,三种情况下半导体温差片的输出电流、输出电压和输出功率均增加.两片半导体温差片串联时组件输出电压高于单片输出和两片并联时的输出电压;两片半导体温差片并联时组件输出电流高于单片输出和两片串联时的输出电流;两片半导体温差片串联时组件输出功率高于单片输出和两片并联时的输出功率,约是单片输出的2倍.采用焦距为13.1cm的菲涅尔透镜聚光,当温差片位于离菲涅尔聚光镜面约12cm时,输出电流和输出功率达到最大值.  相似文献   

7.
本文建立了一类不可逆固体氧化物燃料电池(SOFC)与半导体温差热电发电器(TEG)的混合发电系统模型,基于非平衡态热力学理论,导出混合系统一些重要性能参数诸如输出功率、效率和最小电流密度等的一般表达式,分析系统的性能特性和优化性能,给出系统在最大输出功率或最大效率时的优化条件,确定系统一些重要性能参数的优化工作区域,详细讨论系统的一些主要不可逆性对系统优化性能的影响,得到一些有意义的新结论.所得结果可为实际混合发电系统的设计和优化运行提供理论依据.  相似文献   

8.
半导体温差发电器的输出功率   总被引:10,自引:0,他引:10  
应用非平衡态热力学理论,并从热传导方程出发,分析傅里叶热流、焦耳热和汤姆孙热等因素对半导体温差发电器性能的影响,导出发电器的输出功率一般表示式,探讨最大输出功率及其有关的优化条件.得到一些有意义的新结论.  相似文献   

9.
在低温差斯特林发动机的功率预测和参数优化分析中,传统的分析方法并不实用。为了快速准确地预估低温差斯特林发动机的输出功率,文中研究二阶Simple模型在低温差斯特林发动机的热力学循环分析中的应用。描述了低温差斯特林发动机的简化结构模型与内部工质的温度特性,基于Simple模型推导低温差斯特林发动机中非理想换热器的实际换热方程式,分析发动机的回热损失、泵送损失和换热器实际换热量。通过实例计算说明低温差斯特林发动机系统内部工质的温度、压力和能量随曲柄转角的变化,分析低温差斯特林发动机的理论输出功率。将低温差斯特林发动机在不同加热温度下的实际输出功率与Simple模型的计算功率对比,对比结果显示,Simple模型计算的输出功率与实际输出功率之间的误差较小,表明Simple模型与低温差斯特林发动机的实际循环吻合较好。为了研究低温差斯特林发动机中回热器对发动机性能的影响,文中优化了低温差斯特林发动机的回热器结构,将回热器优化后的实际输出功率和Simple模型计算功率,与回热器优化前的实际输出功率和Simple模型计算功率对比。对比结果显示,优化回热器后的低温差斯特林发动机的实际输出功率与Simpl...  相似文献   

10.
太阳能电池输出功率随着温度升高而降低,半导体温差发电模块输出功率随着温差的增大而升高.结合两者输出功率随温度变化的关系,利用烟囱效应巧妙设计了一套具有负反馈作用的光伏 温差联合发电系统,并对其进行了效率和环境分析.结果表明:系统处于稳定工况时,温差模块可以提供输出功率4.3 W,光伏电池比自然冷却方式下的输出功率增加6.9%,系统的光电转换效率增加1.42%,效率达到12.06%,在寿命期内比火力发电减排NOx 9.7 kg、CO2 742.9 kg、SO2 9.6 kg;系统可以有效地控制电池板与环境的温差在22 ℃左右,增加电池板的使用寿命,这对可再生能源的应用具有理论指导意义.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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