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1.
海洋温差能是一种环境友好型、可持续利用的清洁能源,但是较低的海洋温差能发电系统效率阻碍了海洋温差能发电的商业化应用。提出一种新式循环,采用氨水混合工质,以及贫氨溶液回热和中间抽汽回热方式,实现对贫氨溶液及乏汽的热量二次回收利用。基于能量守恒方程和热力学定律,通过对循环中各设备部分建模分析,构建了新循环的热力模型,并与海洋温差能发电常用循环——朗肯循环进行性能对比分析,结果表明,新循环的热效率与净输出功相比朗肯循环均有显著提高,循环热效率最高可达4.565%,相较朗肯循环提高了25.9%。15 kW等级海洋温差能发电系统中,新循环的净输出功为7.038 kW,高于朗肯循环中的5.343 kW。新循环模型的建立及由此得到的各部分性能分析结果,可为海洋温差能商业化开发提供基础数据理论支撑。 相似文献
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海洋热能是清洁的可再生能源,全球海洋中蕴藏着丰富的热能资源,开发利用潜力巨大,它有可能成为21世纪人类解决能源短缺、全球变暖和淡水缺乏等问题的有效手段.目前,许多国家都在考虑海洋温差发电的问题,其中法国、日本、美国和印度的海洋温差发电技术发展比较快,已经建成了一些海洋温差能发电站,我国正处于研究试验阶段.文章结合全球大洋可利用的海洋温差能资源,回顾了世界海洋温差发电技术的发展历史,重点介绍了法国、日本、美国和印度的发展情况,希望我国积极开展海洋温差发电技术研究. 相似文献
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受专利保护和技术封锁的制约,海洋温差能发电关键技术及设备国产化问题亟待解决。以建造大型温差能发电平台为背景,通过建立朗肯循环OTEC发电系统仿真模型,对比分析R717、R13a和R600工质发电系统性能参数,探索装机规模对热效率和单位换热面积发电量的影响,为大型OTEC发电系统建造提供理论依据和技术支持。结果表明:R717系统在蒸发器和冷凝器热负荷以及工质方面均优于R134a和R600系统。相同装机功率下,R717工质的循环和系统热效率均最大。增加装机规模有助于提升系统的热效率和单位换热面积发电量。R717系统热效率最大,单位换热面积发电量在合适的范围内,是海洋温差发电系统较为理想的循环工质。 相似文献
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海洋温差发电有机朗肯循环工质选择 总被引：3，自引：0，他引：3
为了筛选出适宜于海洋温差热力发电有机朗肯循环的工质.采用PR状态方程计算11种低沸点有机流体工质在闭式海洋温差有机朗肯循环中的热力性能.结果表明,随着工质临界温度升高,循环热效率总体呈上升趋势.正丁烷具有较高的循环热效率,其蒸发压力较低、凝汽压力比较适中,比较适合用作海洋温差发电有机朗肯循环的工质. 相似文献
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国内外海洋温差能发电技术最新进展及发展建议 总被引：1，自引：0，他引：1
国际社会对能源安全、生态环境保护及应对气候变化等问题日益重视,加快开发利用海洋能已成为世界沿海国家和地区的普遍共识。海洋温差能因其"可持续24 h无间歇发电、清洁无污染"等特点受到各国青睐,纷纷通过制定中长期发展路线和布局以推动海洋温差能技术发展。文中对温差能开发利用技术进展情况进行了总结归纳,对比了国外已建项目的技术特点,重点对近年来国外海洋温差能开发利用技术最新进展进行总结,对海洋温差能发展趋势及前景进行展望,并结合实际情况对我国开展海洋温差能开发利用技术提出建议。 相似文献
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最近,在东京举行了美日海洋能源学术讨论会,探讨了今后五十年内海洋能源的开发动向。会上,美国国家海洋大气局海洋工程技术处处长J、R、Vadus予测:五十年后,世界油汽资源将消耗殆尽,煤将是廿一世纪的重要燃料。由于燃煤会带来一系列的不良后果,而海洋蕴藏着取之不竭、且毫无污染的能源,因此人们将把注意力集中在海洋能源的开发上。目前,各国均大力开展波浪、海流、盐度梯度差、温差发电的研究;随着技术的发展,温差发电将成为廿一世纪的实用能源。一些试验性温差发电站(如夏威夷10KW电站、日本在(?)鲁岛的30KW电站等)已投入使用,这就为进行大规模温差发电研究奠定基础。 相似文献
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《海洋技术学报》1986,(1)
日本东电设计公司最近完成了海洋温差发电商用设备的设计工作。并准备销售给南大平洋附近的瑙鲁共和国。这是迄今为止世界上第一次OTEC商用设备设计,对于海洋热能转换技术必将产生深远的影响。还是在十四年以前,东电设计公司便从事海洋温差发电实用化的工作。该公司在发电设备的研究方面,始终处于领先的地位。经过多年的研究,他们的热交换器等设备、系统设计等方面已渐趋成熟,使得海洋温差发电具备了较为充分的商业基础。该公司设计的这种商用发电设备,功率为500千瓦,扣除本身的电力消耗,净功率为300-500千瓦。计算表明,当使用温差为22℃(29℃和7℃)时,使用氟利昂作为推动透平旋 相似文献
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应山东海洋湖沼学会理事长、山东海洋学院院长文圣常教授邀请,日本长崎大学工学部教授栗须正登博士及日本芝浦工业大学工学部研究所嘱托铃木晴之教授予84年12月15日抵达海洋学院访问讲学。栗须正登教授和铃木晴之教授多年来从事海洋温差能利用之研究。在海洋温差发电、海洋温差制淡、温泉发电等方面的模拟试验和海上试验工作中取的众多成果。 相似文献
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根据海洋温差能转换(OTEC)工艺过程的特点,分析了海洋温差能开发对海洋生态环境的特殊影响。认为大流量吸排水形成的大尺度水团在海洋中的重新分布,致使厂址周边海水的层化结构和环流结构以及海水盐度、溶解氧和营养水平等参数发生变化,进而对海洋环境造成很大改变,形成了OTEC技术特殊的环境影响方式。还着重分析了羽状流对初级生产力的影响,以及卷载和冲击对海洋生物的影响,分析归纳了海洋温差能开发生态环境影响的关键评价因子,对下一步的研究重点提出了建议。为未来开展洋温差能开发以及全面评价海洋温差能开发造成的生态环境影响提供技术参考。 相似文献
13.
Chih Wu 《Ocean Engineering》1987,14(4)
Maximum power and efficiency at the maximum power of an irreversible OTEC heat engine are treated. When time is explicitly considered in the energy exchanges between the heat engine and its surroundings, it is found that there is a bound on the efficiency of the real OTEC heat engine at the maximum power condition. This bound can guide the evaluation of existing OTEC systems or influence design of future OTEC heat engines. 相似文献
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Grard C. Nihous 《Ocean Engineering》2007,34(17-18):2210-2221
An interhemispheric box model of the Atlantic thermohaline circulation (THC) is modified by replacing the tropical box with two vertically resolved sub-domains. Seawater flows from large-scale ocean thermal energy conversion (OTEC) are allowed in one of the tropical sub-domains. Under present conditions and standardized OTEC operations, steady-state net power production density would reach a maximum of about 80 kW/km2 (corresponding to 1.8 TW) with a cold seawater withdrawal per unit area of about 14 m/yr. This maximum reflects the impact of large OTEC flows on the oceanic thermal structure, although the THC would not be significantly affected. It is larger than a recently suggested worldwide value of the order of 30 kW/km2 because of the relative strength of the Atlantic THC. Under asymmetric high-latitude warming scenarios potentially representative of current climatic trends, a substantial weakening or a reversal of the THC are possible. In the former case, recoverable OTEC resources could practically vanish. In the latter case, the emergence of a stronger reverse THC eventually could boost OTEC resources. Such events are hypothetical and would unfold over centuries, but the mere possibility of their occurrence challenges the accepted notion that OTEC resources are forever renewable. 相似文献
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To minimize cold water pipe lengths, the most favorable land or fixed platform based Ocean Thermal Energy Conversions (OTEC) sites have subbottom slopes greater than 5°. Observations at OTEC sites in Hawaii indicate that turbidity currents of an impulsive or episodic nature can occur with frontal speeds of several meters per second. Such speeds and the attendant potential for sediment transport and abrasion along routes containing OTEC installations indicate that the pertinent features of these flows are an important design criteria for OTEC or any other steep-slope marine installation. To satisfy this need, models of oceanic turbidity flows and similar flows have been examined. The model that addresses OTEC steep-slope conditions most succinctly was developed originally by Hopfinger and Tochon-Danguy (1977) for snow avalanches on land. This two-dimensional avalanche model is used to estimate the speed and growth characteristics of potential turbidity currents downslope for various postulated marine conditions of initial flow density, height, volume, and length at slopes from 5 to 60°. The areas of additional research required to increase reliability of the analyses are in the initiation and initial development of a turbidity plume, the mechanisms of sediment entrainment to and loss from the plume, and three-dimensional in addition to two-dimensional studies. 相似文献
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Revisiting ocean thermal energy conversion 总被引：1，自引：0，他引：1
Increasing concerns regarding oil spills, air pollution, and climate change associated with fossil fuel use have increased the urgency of the search for renewable, clean sources of energy. This assessment describes the potential of Ocean Thermal Energy Conversion (OTEC) to produce not only clean energy but also potable water, refrigeration, and aquaculture products. Higher oil prices and recent technical advances have improved the economic and technical viability of OTEC, perhaps making this technology more attractive and feasible than in the past. Relatively high capital costs associated with OTEC may require the integration of energy, food, and water production security in small island developing states (SIDSs) to improve cost-effectiveness. Successful implementation of OTEC at scale will require the application of insights and analytical methods from economics, technology, materials engineering, marine ecology, and other disciplines as well as a subsidized demonstration plant to provide operational data at near-commercial scales. 相似文献
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An investigation has been made of available data on the saturation state of seawater with respect to calcium carbonate and its possible significance for scale formation on Ocean Thermal Energy Conversion (OTEC) heat exchangers. Pertinent oceanographic data is lacking at or near potential OTEC sites for the calculation of the degree of saturation of seawater with respect to calcium carbonate. Consequently, only “extrapolated” saturation values can be used. These indicate that near surface seawater is probably supersaturated, with respect to the calcium carbonate phases calcite and aragonite, at all potential OTEC sites. The deep seawater that would be brought to the surface at the potential Atlantic Ocean sites is also likely to be supersaturated with respect to calcium carbonate. The deep seawater at the potential Pacific Ocean sites may be slightly undersaturated.The fact that OTEC heat exchangers will be operating in seawater, which is supersaturated with respect to calcium carbonate, means that if nucleation of calcite or aragonite occurs on the heat exchanger surfaces, significant growth rates of calcium carbonate scale may be expected. The potential for calcium carbonate nucleation is highest at cathodic metal surface locations, which are produced as the result of aluminum corrosion in seawater. Consequently, corrosion and scale formation may be closely related. What the possible effects of biofouling may be on this process are not known. 相似文献
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The applicability of chlorine to control Ocean Thermal Energy Conversion (OTEC) biofouling was investigated.Onsite hypochlorite generation was found to be the preferred method of chlorination. The major fouling organisms of concern to OTEC are the microfouling organisms, that is, initial slime layers. However, macrofouling organisms may become a problem after several years of plant operation. Continuous low-level chlorination is more effective against hard-shelled macrofouling organisms and soft-shelled organisms, whereas intermittent chlorination will control slimes and soft-shelled organisms.Actual on-site experimentation is needed before effective doses and chlorination regimes can be recommended. The doses and regimes may vary depending upon whether the condenser and/or evaporator heat exchangers are chlorinated. 相似文献
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Shelf-mounted Ocean Thermal Energy Conversion (OTEC) plants require installation of cold-water pipes (CWP) on slopes of40deg to depths of 1000 m. In addition, tower platforms containing OTEC power systems may be located on lesser sloped terrain near shore and exposed to special environmental loading problems affecting foundation design. Shelf-mounted installations require careful attention to site selection and geotechnical considerations for foundation integrity on sloped surfaces. This paper primarily discusses research associated with cold-water pipe and foundation installations on steep slopes, although research continues on tower platforms located on the shelf. At least five nations are in various stages of development of OTEC systems for island applications. Each of their systems is either shelf mounted or land based and requires that a large diameter cold-water pipe be installed on a steep slope to provide cold water from 1000-m depths. In addition to the installation and deployment of the large cold-water pipe, the most significant problem is the design and installation of suitable foundations that will last for several decades. To date there is very little experience in the offshore industry for large installations on steep slopes. A major scale-model research project is underway on the slopes of the island of Hawaii. A section of pipe 2.4 m in diameter and 24 m long was installed using combination concrete foundations and joints. The pipe and foundations are fully instrumented to measure environmental loading forces due principally to currents and waves. Environmental measurements will also be taken in the test area. The measurement data will be used to validate available analytical models for subsequent use in aiding industry in providing more cost-effective designs for OTEC pipes and foundations. 相似文献