LED通用照明若干先进技术简介

回顾了LED通用照明的发展,分析了当前LED在通用照明领域的应用现状与展望,对这一领域中的一些先进技术,如远程荧光粉技术、驱动技术、光学设计技术、机械设计技术等做了介绍。     

LED照明技术研发壁垒探讨

近20多年来,LED已在发光效率、寿命、稳定性等方面取得了巨大的突破,孕育着21世纪照明的革命.但目前LED光源在芯片质量、光电性能、封装工艺和材料、散热技术、驱动电路、非成像光学设计、相关标准和性价比等方面还存在问题,使LED在照明的推广应用中呈现说易行难的局面.因此试图通过对研发LED光源的壁垒进行探讨,结合LED...     

基于太阳能斯特林发动机的反射式二次聚光器设计

针对透射式太阳能斯特林发动机实验教学平台运行过程中因一次反射光线直接逃逸导致的光学损失问题,在太阳能斯特林发动机热端增设一个反射式二次聚光器,不仅增加光线被拦截次数来提高光学效率,而且增大菲涅尔透镜对入射光线的跟踪误差容忍角度。该文给出了具体的设计实例,并应用Solidworks软件和Tracepro软件对该设计实例进行了光学建模和仿真模拟。结果表明,当光线垂直入射时,相较于未增设工况,增设该二次聚光器的太阳能斯特林发动机光学效率提高了87.3%;增设该二次聚光器使得菲涅尔透镜对入射光线的跟踪误差容忍角度增至1.5°,对应的光学效率为光线垂直入射时的97.2%。     

基于物联网的太阳能LED路灯智能照明云控制系统的设计与研究

针对传统太阳能LED路灯照明系统普遍存在的故障判断困难、巡检难度大、人力成本高等问题,设计开发了一种具有远程智能化控制的基于物联网的太阳能LED路灯智能照明云控制系统;从系统构架、硬件设计、平台建设、实验测试等方面,详细介绍了该云控制系统的设计与研究过程,并对该云控制系统的运行工况进行了实验测试。测试结果表明：基于物联网的太阳能LED路灯智能照明云控制系统可随时掌握太阳能LED路灯的运行工况并进行远程控制,及时发布故障警示,可满足道路照明智能化监测、运维的需要,实现了远程智能化控制,具有广阔的应用前景。     

基于多平面拟合的菲涅尔透镜优化研究

提出一种第一环中心透镜为球面,第二环起的外侧环带为倾斜平面的应用于高倍聚光光伏的等厚型菲涅尔透镜设计方法,并对前几环透镜进行基于多个倾斜平面拟合的优化设计,在此基础上进行光学仿真和实验验证,结果表明优化后透镜光学效率和光斑能量均匀性均有明显提升,透镜的实际光学效率可满足设计要求。该设计可为高倍聚光光伏模组用菲涅尔透镜的工程应用提供参考。     

LED照明新一代的绿色光源

超高亮度白光LED的问世是人类照明史上一个重大的里程碑,标志着一种全新的照明光源的诞生.LED照明的高效、节能、环保、寿命长的显著特点,使其在照明领域的前景备受全球瞩目.本文简要介绍了LED的发展、特点、应用以及我国当前LED产业概况,以期能对LED照明及其产业发展有所认识.     

350 MW机组锅炉热二次风道优化设计分析

针对350 MW机组锅炉矩形热二次风道钢材耗量大、初投资高的问题,结合沧州运东2×350 MW热电联产工程,对热二次风道进行设计优化,替代常规矩形风道,工程实现了圆形热二次风道的设计,使钢材耗量明显减少,节省了初投资。     

太阳能LED杀虫灯的研究

太阳能光伏和LED照明技术是最有前景的无公害灭虫技术之一.为了开发低成本的无公害灭虫技术,设计了一种太阳能光伏LED杀虫灯系统.通过试验研究,取得了一定的效果.文章简述了害虫的趋光性、LED灯的光学特性和基于LED的杀虫技术.     

LED在绿色节能照明中的应用进展

阐述了LED电光源的特性及在绿色节能照明中的地位;介绍了IED照明光源的发展、IED光源的设计和与太阳能相结合的LED光源的实际应用;对LED替代传统照明做了市场分析;对其发展前景做了分析和展望.     

LED照明要素及选择LED照明产品的三大误区

低碳照明(节能照明)是当今世界照明产业发展的主旋律,大力发展价廉物美、能被千家万户接受的LED照明是时代的必然要求。然而,在迅猛发展起来的成千上万的LED照明企业中,产品鱼龙混杂,使消费者真伪难辨。因而,正确理解LED通用照明的要素,有利于LED照明产业可持续发展。由于LED照明与传统的照明技术有很大的不同,文章从LED照明的技术特点出发,解释了通用照明基本性能要求的含义,供从事LED节能照明的相关人员及希望对LED照明产品有理性了解的广大消费者参考。     

Energy efficient lighting meets real home life

Will the phase-out of inefficient lighting in the European Union (EU) lower consumption of residential electricity significantly? Will light-emitting diode (LED) light replace other technologies for lighting in the near future? Implementation of the phase-out decision in the EU will push demand for efficient lighting technologies. One of the most efficient types, light-emitting diodes, promises even greater reductions than CFLs. However, in order to reap the gains from LEDs they must replace existing lamps and luminaires. This paper reports the findings from tests of LED lights in real homes. It points at the limits of the LED technology at sale in the market today, and the risk for a rebound effect. This paper also addresses the more general issue of theoretical development in the area of residential use of electricity. A “frame of interpretation” is presented in which the use of the lighting set in a home is the foundation. From this, sociotechnical and path-dependent aspects on technical and cultural inertia and marginal change can be developed.     

Road lighting energy-saving system based on wireless sensor network

An intelligent wireless sensor network that is designed to save road lighting energy, while maintaining traffic safety, is presented. It consists of an array of nodes that may be installed on both sides of the road, being mutually separated by a few tens to a few hundreds of meters. Each node consists of (i) vehicle detection subsystem, (ii) wireless communications and control subsystem for message exchange between the neighboring nodes, and (iii) lighting subsystem. During the day, nodes are inactive, while during the night, they turn to an active mode enabling detection of passing vehicles and timely activation of road lighting. Upon detection of a passing vehicle, the node generates a wireless message. Neighboring nodes that receive the wireless message will turn on their road lighting. In order to prevent driver distraction, each lamp will be turned on at a safe distance ahead of the moving vehicle. In order to improve energy efficiency, the lights will be dimmed or turned off behind the passing vehicle. The proposed road lighting energy-saving (RLES) system, which combines advanced sensor and wireless communication technologies, is suitable for implementation both with existing high-intensity discharge (HID) lamps and new light-emitting diode (LED) lamps. Our analysis shows that the RLES system will pay off in less than a year when used with HID lamps, while pay-back period is less than two and a half years when used with LEDs.     

Economic feasibility of solar-powered led roadway lighting

The optical efficacy of light emitting diode (LED) has exceeded 72 lm/W in 2006. This implies that energy can be saved about 75%, as compared to mercury lamps widely used in roadway lighting. In some remote areas where the grid power cannot reach, independent solar-powered lighting using high-power LED provides a promising solution. However, the cost of solar photovoltaic device may cause the application of solar-powered LED roadway lighting to be not economically feasible.The present study investigates the design of the solar-powered LED roadway lighting using high-power LED luminaire (100 W) and estimates the installation cost for a 10 km highway with 2 lanes. LED luminaries are installed on both side of the road with staggered arrangement. The pole distance is 30 m. The cost comparison of LED lighting using grid and solar power with the conventional mercury lamps was carried out. It shows that the installation cost is 22 million USD for LED powered by grid power and 26 million USD for solar-powered. The total installation cost of conventional mercury lighting is 18 million USD. The excess cost of LED mainly comes from the cost of LED lamp and solar PV. But, the cost of power generation and electrical transmission line can be greatly reduced since about 75% energy was saved for LED. This permits the use of smaller copper wire and shorter line length for solar-powered system which in turn saves installation cost. The payback time for the excess investment of LED is 2.2 years for LED using grid power and 3.3 years for LED using solar power.     

Off-grid energy services for the poor: Introducing LED lighting in the Millennium Villages Project in Malawi

Lanterns that use light-emitting diodes (LEDs) powered by batteries, which are in turn charged by grid electricity or small solar panels, have emerged as a cost-competitive alternative to kerosene and other fuel-based lighting technologies, offering brighter light for longer duration at equal or lower cost over time. This paper presents lessons learned from the introduction of solar LED lanterns in rural Malawi. We discuss a market-based program using new and existing local commercial structures such as vendors and cooperatives to sell lanterns to village households without subsidy. The paper addresses issues of enterprise development, community interactions, and survey data on lighting use and expenditure patterns before and after LED lantern introduction. Households that purchased a lantern reported high levels of satisfaction with the LED lanterns as well as savings in annual kerosene expenditure comparable to the price of the lantern. These households also reported monthly incomes comparable to the price of the LED lanterns whereas non-adopters surveyed reported monthly incomes about half this level, suggesting a need for financing options to maximize adoption among poorer populations in rural areas. These results suggest that similar market based models of LED lighting technology dissemination have the potential to be replicated and scaled up in other off-grid regions in developing countries. However, viability of local cooperatives and supply chains for lantern products over the medium-to-long term remain to be assessed.     

The benefits of the transition from fossil fuel to solar energy in Libya: A street lighting system case study

The Libyan economy is dominated by the oil and the gas industry which are considered as the primary energy sources for the generating power plants. With the increased energy demands in the near future, Libya will be forced to burn more oil and gas. This, in turn will result in reducing the country revenue, threatening the economy and increasing the CO₂ emission. This triggers the alarm for Libya to an urgent plan to diversify the energy sources through using sustainable energy. The sun showers Libya every day by a huge amount of sunshine, especially during the peaks in the summer days. Recently, the country has been struggling to satisfy its escalating energy demands. The residential and street lighting loads constitute more than 50% of the electricity demands in Libya. Street lighting consumes more than 3.996 TW h, which is around one fifth of the energy demands in Libya. Energy conservation and transition from fossil fuel to renewable energy could have significant profit on the energy sector in Libya. For example, Libya is still relying on the old-fashioned, inefficient and unsustainable street lighting systems. Replacing the old technology lighting systems with up-to-date solar powered lighting system can achieve energy saving and sustainability. In this paper, improving the energy situation in Libya through replacing the high pressure sodium street lighting systems with solar powered LED street lighting systems is investigated. A four km road is chosen as a case study. Four alternatives are analyzed; grid-powered high pressure sodium lamp street lighting system, grid-powered LED lamp street lighting system, stand-alone solar powered LED street lighting system and grid-connected solar powered LED street lighting system. The four options are compared in terms of the capital cost, maintenance cost, total cost, fuel cost and the CO₂ emission. Replacing the high pressure sodium lamp system with LED lamp system saves 75% of energy and reduces the CO₂ emission by 75%. The stand-alone solar powered LED lighting system cuts the CO₂ emission, saves the fuel and is economically feasible. Furthermore, improvement is attained if the solar powered lighting system is connected to the grid where the excess energy is fed to the grid. The two solar powered options are economically feasible and sustainable.     

上海世博会节能新技术成果应用

文章针对2010年上海世博会期间应用的节能技术进行了总结。其中照明节能技术介绍了包括LED节能光源、互动型智能帷幕、智能照明系统、定日镜技术应用:主动式导光系统和向日葵太阳光采光导入系统在内的技术;暖通节能技术介绍了包括细水雾降温系统、热回收新风系统、地源热泵技术和生态气候设计在内的技术;净水技术介绍了人工湿地水处理系统和纳豆菌净化水体技术在内的技术。以期对部分世博会的优秀节能技术进行介绍并对其在后世博的应用进行简单探讨。     

Potential of new lighting technologies in reducing household lighting energy use and CO2 emissions in Finland

Using light-emitting diodes (LEDs) can significantly reduce the current household lighting energy use in Finland during 2020–2050. Our calculations show that the potential of using LEDs in reducing household lighting energy use and corresponding CO₂ emissions in Finland during 2020–2050 can be significant. Reductions from the current level of Finnish household lighting energy use (1.8 TWh/a) were 59 % in 2020, 72 % in 2030 and 78 % in 2050, when a high LED penetration was assumed. Lighting energy savings in 2020 would mean a 1.3 % reduction from the current total electricity use in Finland (84.2 TWh/a). The starting point in 2012 was that the share of incandescent lamps was 32 % and the share of LED lamps 6 % of the total amount of lamps in an average household. Using the current average emissions factor (current electricity production structure), the saved amount of energy in 2020 means 234,000 tonnes of CO₂. Using the marginal emissions factor, the saved amount of energy means 920,000 tonnes of CO₂ emissions.     

Environmental and economical impact of LED lighting systems and effect of thermal management

Solid‐state lighting (SSL) technologies such as light emitting diodes (LEDs) have been of interest for the last 15 years. This article focuses on inorganic LED technology and their evolving applications, energy efficiency, and economic impact as well as the effect of thermal management on LED lighting systems. The efficacy of the best commercial 1 W LED packages currently surpasses 120 lm/W, which is more efficient than typical metal‐halide and fluorescent lamps. This high efficacy will eventually allow LED lighting systems to be used in specialty and general illumination applications. However, higher lumen requirements for LED systems will inevitably lead to significant thermal challenges at both the chip and the system level that need to be addressed to enable practical applications at low costs. In this article, the basics of LED lighting will be discussed first. It will be followed by the potential economic benefits for high efficiency LED lighting systems in the general illumination market. We will then discuss the thermal challenges and possible candidate cooling technologies in LED lighting systems. Copyright © 2009 John Wiley & Sons, Ltd.     

From carbon to light: a new framework for estimating greenhouse gas emissions reductions from replacing fuel-based lighting with LED systems

There is considerable well-intended, yet wishful anticipation about reducing greenhouse gas emissions by replacing fuel-based lighting in the developing world with grid-independent light-emitting diode (LED) lighting systems. Most estimates gloss over important practical realities that stand to erode a genuinely significant potential. The Clean Development Mechanism (CDM) is the leading system for quantifying the benefits of such projects in developing countries and embodying them in a market-based platform for trading carbon credits. However, compliance with methodologies for highly decentralized, small-scale energy saving projects currently employed in the CDM is viewed by developers of as onerous, time-consuming, and costly. In recognition of the problem, the CDM has recently placed priority on improved methodologies for estimating carbon dioxide reductions from displacement of fuel-based lighting with energy-efficient alternatives. The over-arching aim is to maintain environmental integrity without stifling sustainable emission-reduction projects and programs in the field. This article informs this process by laying out a new framework that shifts the analytical focus from highly costly yet narrow and uncertain baseline estimations to simplified methods based primarily on deemed values that focus on replacement lighting system quality and performance characteristics. The result??many elements of which have been adopted in a new methodology approved by the CDM??is more structured and rigorous than methodologies used for LED projects in the past and yet simpler to implement, i.e., entailing fewer transaction costs. Applying this new framework, we find that some off-grid lighting technologies can be expected to yield little or no emissions reductions, while well-designed ones, using products independently certified to have high quality and durability, can generate significant reductions. Enfolding quality assurance within the proposed framework will help stem ??market spoiling?? currently underway in the developing world??caused by the introduction of substandard off-grid lighting products??thereby ensuring carbon reduction additionality (emissions reductions that would have not occurred in the absence of the CDM program).     

Thermoelectric transformation and illuminative performance analysis of a novel LED-MGVC device

Energy-efficient, small and lightweight high-power light-emitting diodes (Hi-LEDs) are combined with a thermo-generation module (TGM) to transform the heat power generated by the LED into electric energy in the present paper. Variation in the dielectric copper and solder layer thickness in the printed circuit board (PCB) composite was found to affect the thermal performance of the Hi-LEDs lighting system, and a vapor chamber (VC) was shown to provide excellent heat dissipation performance when used with Hi-LEDs. Therefore, VC and PCB (VCPCB) were combined for integration with the Hi-LEDs package system (micro-generator with LED vapor chamber-based plate, LED-MGVC) for performance and illumination comparison. This study analyzes the performance of a novel LED-MGVC device using experimental and illumination-analysis methods with VCTM V1.0. Results depict that the LED-MGVC system provides significant improvement for thermal performance and illumination and thermoelectric properties.