Efficient Lamps Research Articles

Research and Application of Green Lighting in Power Plant

To study the application of green lighting in power plant, this paper based on the analysis and comparison of the technical and economic of lighting source and energy-saving lamps and accessories, recommended the use of high luminous efficiency of lamps and lanterns, to achieve energy-saving effect. From the point of lighting design, through the calculation of the illumination value and the use of reasonable lighting control to achieve the effect of green lighting. By adopting the new energy saving lamps and light sources, the operation cost of the power plant and the lighting energy consumption can be reduced, the project investment and operation cost can be saved, and the social and economic benefits will be obtained.

Increasing luminous efficiency of led by joint dimming mode with adjustable peak current

Luminous efficiency and color temperature of LED chip are affected by current and temperature. PWM dimming mode only works at two kinds of current levels-rated current and zero current. It has smaller effect on color temperature compared with linear dimming mode, but it will reduce the luminous efficiency of lamps. Linear dimming mode has higher luminous efficiency by comparison. The two dimming modes above cannot keep color temperature stable and Luminous efficiency high. Therefore, the paper designed a joint dimming mode by integrating advantages of the two modes. The dimming method not only adjusts peak current, but also changes the duty cycle of dimming signals. The injected average current is kept stable by reducing peak current and increasing the duty cycle. The decreased luminous efficiency by the raise of temperature was made up for. Then according to the mathematical model of total flux and current, the author calculates the mathematical mode of flux affected by temperature. It proves the fact that adjusting peak current slightly can compensates for the reduced luminous efficiency affected by temperature through theoretical calculation. In addition, the final peak current after calculation can contribute to the adjustment parameter of joint dimming modes.

The Effect of Consumer Behaviour on the Life Cycle Assessment of Energy Efficient Lighting Technologies

Energy efficient lamps offer significant energy savings throughout their life. However, there is a variety of energy saving lamps available and it is unclear which impacts the environment least throughout the lifecycle under different use patterns. Different use patterns have a significant impact on the lifetime of each light globe alternative and therefore affect the life cycle impact of each globe.This paper undertakes a series of Life Cycle Assessments on two alternative lighting choices (Light Emitting Diodes and Compact Florescent Lamps) under a range of use conditions. It was found that the environmental impacts were comparable for CFLs and LEDs, though significantly less than traditional incandescent, for a range of different use cases. The sensitivity analysis carried out shows that the variation in lamp parameters has a far greater effect on the lifecycle impact rather than the use patterns.

A review of solid-state lighting and its impact on the marketing and production of decorative coatings

Solid-state lighting in the form of light emitting diode lamps is quickly taking over the world as replacements for existing lower efficiency lamps. The lighting standards, which phased in from 2012 to 2014, do not ban incandescent or any specific lamp type, but they do require that lamps need to use about 25% less energy. The bipartisan Energy Independence and Security Act of 2007 (EISA 2007) established these efficiency standards. Many commercial lamps meet these new standards, including halogen incandescent filament, CFLs, and LEDs. The new bulbs provide a wide range of choices in color and brightness, and many of them last much longer than traditional lamps. However, the spectral distribution of flux from some of these new lamps do not match or even correspond to the spectral power distribution of traditional office and home lighting. In this review, the impact of the new lamp lights on the design, marketing, and production of modern decorative coatings is assessed. The decorative coatings industry has followed recommended guidelines for many decades, producing color-matches that are acceptable under a series of standard illuminants (D65, CWF, A) which are representative of the lamp lights in most common facilities. The new solid-state lamps do not render object colors in ways similar to the currently adopted standardized illuminants. The primary obstacle to the coatings manufacturer is the lack of standards on how to test color-matches for quality conformance under the new lamp lights. As the energy efficient lighting industry is currently still in a technologically developing phase, it appears that it will be some time before any agreements on the characteristics of modern lamp light will be reached. Therefore, guidance is provided on creating and/or using illuminant data representative of these lamps until official reference illuminants are published.

Life time comparison of LED package and the self-ballasted LED lamps by simple linear regression analysis

The energy efficient long-life self-ballasted LED lamps are designed considering the reliability test result of LED package. We also try to predict the lumen maintenance life for the self-ballasted LED lamps because there were a lot of failure mechanisms for a various environment stress. Many studies have investigated the environmental stress effects on LED packages [2,3,4, and 5]. However, comparing to LED package, there is not enough data to study the lumen maintenance life for the self-ballasted LED lamps. IES LM-80-08 is the approved method for measuring lumen maintenance of LED light sources [1]. It suggests using the Arrhenius Equation to calculate the interpolated lumen maintenance life. We followed this method and obtained lumen degradation patterns from three different thermal stresses as indicated in the IEC 62621 standard. Under the three different thermal stresses, the on-off test (30on and 30s off) was conducted on the self-ballasted LED lamps which were made of the same selected LED package (3V, 64mA). The intent of the research isn't to set up a new curve-fit for non-linear lumen degradation pattern. Our research goals are to find methods to compare the lumen degradation pattern of LED package and the self-ballasted LED lamp using simple linear regression analysis. As simple straight linear line is assumed for lumen degradation after ALT testing We found the slope of the mathematical model is easily comparable for three different temperatures and for different number of LED whether it is single or consists of forty or eighty LED. By comparing each values of the slope the effect of increase in number of LED can be shown at each thermal stress. This study is the first step towards the presentation on the lumen maintenance life of the self-ballasted LED lamp on three different temperatures. Additional information must be accumulated in the future to further study on the LED lighting product reliability.

An Approach to Interior Lighting Design for a Heritage Building

Heritage Buildings are essential assets of a city because these comprise of various archival and rare collections of paintings, sculptures, photographs, periodicals, costumes, curio pieces etc. So maintaining the internal and external architectural lighting characters is important for preventive preservation. Therefore Interior lighting designing approach is one of the significant for achieving this goal. This approach follows specific guidelines but it can be varied depending upon the designer's choice. Jorasanko Thakurbari in Kolkata is a Heritage building with over 200 years of socio cultural history that has interested many historic events as the family abode of the erstwhile Tagores. This paper attempts to give a brief idea about the interior Lighting design approach followed for some typical galleries of Thakurbari with the help of modern and energy efficient lamp using DIALux-Lighting Software.

Energy efficiency of lighting installations: Software application and experimental validation

Abstract The rational use of energy and energy-efficient environmental public street lighting is an important topic. In the design of new public lighting installations, national regulations containing energy-efficient guidelines are already used. Nevertheless, either in new installations or in reconstructions of existing lighting, designers do not generally consider all the available means to save energy. In installations of street lighting, energy consumption can be reduced by reducing the losses in the conductors, associated with the efficiency of the equipment, allowing better use of the available energy. The losses in the conductors must be analysed in conjunction with all the loads that contribute to the current in the sections of the installed street lighting. When opting for more efficient lamps and luminaires or lighting control systems, the current decreases in the sections covered with the most significant power loss due to proportionality with the square of the current. This decrease, often forgotten, is considered in this work in the investment analysis of efficiency and sustainable street lighting via simulation and experimental results. This analysis, combined with the features and operating parameters of the electrical installation, accounts for all the gains that can make a difference in the choice of efficient street lighting.

Classification of lighting sources and convenience for lighting fixtures design

Introduction: Until recently the most common electric light source was the incandescent lamp. This is still widely used, although its relatively low energy efficiency is leading to its replacement by other more efficient lamps such as the CFL and LED. Statement of the problem: This paper discusses the types of lighting sources available for light fixtures designers in Egypt. The paper also attempts to relate available light sources with types of lighting fixtures and types of uses in all areas of lighting design. Objectives to classify light sources on basis of type and lighting environment and location nature and the purpose it was designed for. Results: to provide information on how to select a proper light source for the designed space and for types of different users has also been provided in an easily usable format. Artificial light sources are sources other than natural light which developed to compensate for or assist the natural light. These have different frequencies and wavelengths that determine the light color. The study imply that sic understanding of lighting sources fundamentals is essential for designers and decisionmakers who are evaluating lighting upgrades. The study also provides a brief overview of design parameters, technologies, and terminology used in the lighting industry. It also attempts to relate different lighting sources to their corresponding lighting fixtures and lighting applications

High-Color-Quality Multipackage Phosphor-Converted LEDs for Yellow Photolithography Room Lamp

This paper introduces a multi-package light-emitting diode (LED) system with the ability to realize an efficient and good color quality yellow room lamp under a photolithography environment. Various yellow room LEDs were fabricated by combining two, three, and four packages among green (G), yellow (Y), amber (A), and red (R) phosphor-converted LEDs (pc-LEDs) capped with long-wavelength pass dichroic filters (LPDF). The values of luminous efficacy (LE), color rendering index (CRI), and color quality scale (CQS) of the nine combinations of multi-package pc-LEDs are compared and optimized for application to a yellow room lamp. The optical properties of the selected G-A-R multi-package LED are compared with those of fluorescent light tubes (FT) and a yellow fluorescent light tube (YFT), which are generally used in photolithography rooms. The proposed G-A-R multi-package LED provides high luminous efficacy of 100 lm/W and good color quality (CRI of 78 and CQS of 36) at correlated color temperature (CCT) and color coordinates similar to those of currently commercialized YFTs.

Theoretical and Experimental Study of Led Luminaire

Today, the LED illumination takes one of the leading positions in the segment of lighting equipment. This is due to the lighting market demanding energy-efficient and ecologically safe sources of light. The purpose of this project was to investigate the temperature conditions of Сree LEDs, depending on impressed current. The basic idea was to obtain dependencies that could be used to select the optimal operating mode for getting the most LED lamp efficiency. Calculation of thermal conditions was held with the help of a special software application SolidWorks Flow Simulation. In the course of research 5 PCBs mounted on the aluminum housing of the designed luminaire were calculated. On each board different current from 0.35A to 1.5A was impressed. LED quantity on PCBs was chosen so that the luminous flux was the same on all the boards - 5klm. After the calculations the graphs and experiments, reflecting energy efficient characteristics of the luminaire were obtained. The analysis of obtained results elucidates that the operating heat regimes at LED supply currents varying from 0.35 A to 0.7 A are most suitable for the effective work of a lamp. At currents higher than 1 A, there is a considerable drop of the light output. The calculation of LEDs thermal condition (especially, powerful) and the choice of a suitable cooling system is one of the main criteria in the design of a reliable and durable LED lighting system.

The efficiency challenge of nitride light‐emitting diodes for lighting

We discuss the challenges of light‐emitting diodes in view of their application to solid‐state lighting. The requirement is to at least displace the quite efficient fluorescent, sodium, and high intensity discharge lamps used today in the main energy consuming lighting sectors, industrial, commercial and outdoors, with more efficient and better light quality lamps. We show that both from the point of view of cost of ownership and carbon emissions reduction, the relevant metric is efficiency, more than the cost of lumens. Then, progress from present performance requires identification of the loss mechanisms in light emission from LEDs, and solutions competing with mainstream c‐plane LEDS grown on sapphire need to be on par with these. Special attention is devoted to a discussion of the efficiency droop mechanisms, and of a recent direct measurement of Auger generated electrons which appear to be responsible for droop.

Technology for radiation efficiency measurement of high-power halogen tungsten lamp used in calibration of high-energy laser energy meter

The calibration method using a high-power halogen tungsten lamp as a calibration source has many advantages such as strong equivalence and high power, so it is very fit for the calibration of high-energy laser energy meters. However, high-power halogen tungsten lamps after power-off still reserve much residual energy and continually radiate energy, which is difficult to be measured. Two measuring systems were found to solve the problems. One system is composed of an integrating sphere and two optical spectrometers, which can accurately characterize the radiative spectra and power-time variation of the halogen tungsten lamp. This measuring system was then calibrated using a normal halogen tungsten lamp made of the same material as the high-power halogen tungsten lamp. In this way, the radiation efficiency of the halogen tungsten lamp after power-off can be quantitatively measured. In the other measuring system, a wide-spectrum power meter was installed far away from the halogen tungsten lamp; thus, the lamp can be regarded as a point light source. The radiation efficiency of residual energy from the halogen tungsten lamp was computed on the basis of geometrical relations. The results show that the halogen tungsten lamp's radiation efficiency was improved with power-on time but did not change under constant power-on time/energy. All the tested halogen tungsten lamps reached 89.3% of radiation efficiency at 50s after power-on. After power-off, the residual energy in the halogen tungsten lamp gradually dropped to less than 10% of the initial radiation power, and the radiation efficiency changed with time. The final total radiation energy was decided by the halogen tungsten lamp's radiation efficiency, the radiation efficiency of residual energy, and the total power consumption. The measuring uncertainty of total radiation energy was 2.4% (here, the confidence factor is two).

An Economic Evaluation of Energy Management Opportunities in a Medium Scale Manufacturing Industry in Lagos

This paper seeks to increase interest level on energy efficiency by bringing to fore payback-period assessment of implementing energy-efficient measures that could help achieve sustainable production processes in a typical medium scale printing manufacturing industry in Lagos, Nigeria. Several energy efficiency measures have been suggested based on identifiable energy management opportunities within this industry. The method used for the economic evaluation and feasibility study is payback period; this approach is aimed at providing guidance for a quick and informed decision on the implementation of the energy efficiency measures identified. The payback for two of these measures namely; turning off equipment when not in use and replacement of drive belts on large motors with energy efficient cog belts, have been found to be immediate. When standard fluorescent lighting and incandescent bulbs are replaced with energy efficient lamps and bank of capacitors are installed to improve the power factor of the motors, the company will recoup its initial investment in less than one year. Also, purchasing and installing an advanced electronic meter with data logging capability to help monitor electrical demand has been shown to give the highest payback of 2.4 years. These payback period results have indicated that investment in the recommended energy efficient technologies are economically viable and worthy of implementation. With this analysis, management of manufacturing industries can now make informed economic decision towards productivity improvement and sustainability.

Decontamination Efficiency of a DBD Lamp Containing an UV-C Emitting Phosphor.

Among different physical and chemical agents, the UV radiation appears to be an important route for inactivation of resistant microorganisms. The present study introduces a new mercury-free Dielectric Barrier Discharge (DBD) flat lamp, where the biocide action comes from the UV emission produced by rare-earth phosphor obtained by spray pyrolysis, following plasma excitation. In this study, the emission intensity of the prototype lamp is tuned by controlling gas pressure and electrical power, 500 mbar and 15 W, corresponding to optimal conditions. In order to characterize the prototype lamp, the energetic output, temperature increase following lamp ignition and ozone production of the source were measured. The bactericidal experiments carried out showed excellent results for several gram-positive and gram-negative bacterial strains, thus demonstrating the high decontamination efficiency of the DBD flat lamp. Finally, the study of the external morphology of the microorganisms after the exposure to the UV emission suggested that other mechanisms than the bacterial DNA damage could be involved in the inactivation process.

The Study for Saving Energy and Optimization of LED Street Light Heat Sink Design

LED lamps are characterized by high energy efficiency, high luminance, and long lifespans. However, the heat radiation problem caused by the extra high power shortens the lifespan and reduces the luminous efficiency of such lamps. This study introduced the development of a novel cooling fin structure for LED lamps and compared its performance with those of commercially available products. The objective of the design was to reduce the maximum temperature and temperature difference on the fin, the amount of aluminum required for fin manufacturing, and CO2emissions to save energy. The study employed the Taguchi method for experiment planning and used gray relational analysis and principal component analysis to determine the optimal parameter combination for cooling fins. The results showed that the maximum temperature on the fin surface dropped by 2.62°C in environments without forced convection, which indicated improved lighting efficiency. Furthermore, the amount of aluminum used per unit volume for fins was reduced by 15%, which effectively reduced CO2emissions during the manufacturing process.

Improved optical sintering efficiency at the contacts of silver nanowires encapsulated by a graphene layer.

Graphene/silver nanowire (AgNWs) stacked electrodes, i.e., graphene/AgNWs, are fabricated on a glass substrate by air-spray coating of AgNWs followed by subsequent encapsulation via a wet transfer of single-layer graphene (SLG) and multilayer graphene (MLG, reference specimen) sheets. Here, graphene is introduced to improve the optical sintering efficiency of a xenon flash lamp by controlling optical transparency and light absorbing yield in stacked graphene/AgNW electrodes, facilitating the fusion at contacts of AgNWs. Intense pulsed light (IPL) sintering induced ultrafast (<20 ms) welding of AgNW junctions encapsulated by graphene, resulting in approximately a four-fold reduction in the sheet resistance of IPL-treated graphene/AgNWs compared to that of IPL-treated AgNWs. The role of graphene in IPL-treated graphene/AgNWs is further investigated as a passivation layer against thermal oxidation and sulfurization. This work demonstrates that optical sintering is an efficient way to provide fast welding of Ag wire-to-wire junctions in stacked electrodes of graphene/AgNWs, leading to enhanced conductivity as well as superior long-term stability under oxygen and sulfur atmospheres.

Application of high intensity UVC-LED for the removal of acetamiprid with the photo-Fenton process

Research into the use of light-emitting diodes (LEDs) for wastewater treatment has increased in recent years. LEDs are more efficient than other UV lamps because of their reduced heat dissipation and much longer life span. However, most of the UVC-LEDs that are currently available are of such low intensity that the large number of bulbs required for effective treatment of wastewater streams makes their application uneconomic. The development of higher intensity UVC-LEDs may therefore lead to more feasible technology options for wastewater treatment with UV-based advanced oxidation processes (AOPs). The aim of this work was to study the efficiency of high-intensity UVC-LED lamps (20W/m2) for the removal of micropollutants with the photo-Fenton process. The pesticide acetamiprid was used as model pollutant at a concentration of 100μg/L in synthetic secondary effluent due to its recalcitrant nature. Degradation using a low-pressure UVC-lamp (LPL) was also assessed for comparative purposes. The process was operated at pH 2.8 and at natural pH. The volumetric photon absorption (VRPA) was calculated for the results at acidic pH, where the catalyst was soluble, to investigate the influence of iron and hydrogen peroxide concentrations on acetamiprid degradation, based on their absorption for both systems. A model was proposed and results indicated that the contribution of both hydrogen peroxide and iron to the generation of radicals was the same in the LED system. At natural pH, the high intensity LED system was effective in the removal of acetamiprid, achieving degradation in 20min adding 1+1+1mgFe/L (sequential iron dosage) and 12mgH2O2/L.

Photobiological safety of the recently introduced energy efficient household lamps.

Nowadays more and more newly introduced light sources (tungsten-halogen, compact fluorescent (CFL) and light-emitting diode (LED) lamps) are used in households. It is important to know whether their radiation poses any possible risk for human health or not. These light sources emit optical radiation not solely in the visible spectrum. Other bands emitted by these sources, i.e., ultraviolet and infrared, are potentially hazardous for human health. The visible light, especially the blue light, could also damage human retina. The purpose of this study was to determine the ultraviolet (UV) and blue light (BL) emissions from halogen bulbs, CFLs and LED lamps, and to evaluate them from the point of view of possible health risks for general public. The exposure of UV and BL emissions from 19 types of CFLs, 11 types of halogen lamps and 4 types of LED lamps produced by different manufacturers were measured at 200 mm distance from the source. The exposures to UV and BL were below the International Commission on Non-Ionizing Radiation Protection (ICNIRP) exposure limits in spite of the very conservative assumption of the assessment. Results of this study indicate that the UV and BL radiation from the newly introduced lamps does not exceed the current exposure limit values and thus, in comparison with the former incandescent bulbs, does not result in a higher risk for general public.

Household transitions to energy efficient lighting

New energy efficient lighting technologies can significantly reduce household electricity consumption, but adoption has been slow. A unique dataset of German households is used in this paper to examine the factors associated with the replacement of old incandescent lamps (ILs) with new energy efficient compact fluorescent lamps (CFLs) and light emitting diodes (LEDs). The ‘rebound’ effect of increased lamp luminosity in the transition to energy efficient bulbs is analyzed jointly with the replacement decision to account for household self-selection in bulb-type choice. Results indicate that the EU ban on ILs accelerated the pace of transition to CFLs and LEDs, while storage of bulbs significantly dampened the speed of the transition. Higher lighting needs and bulb attributes like energy efficiency, environmental friendliness, and durability spur IL replacement with CFLs or LEDs. Electricity gains from new energy efficient lighting are mitigated by 23% and 47% increases in luminosity for CFL and LED replacements, respectively. Model results suggest that taking the replacement bulb from storage and higher levels of education dampen the magnitude of these luminosity rebounds in IL to CFL transitions.

Simulation and comparison of the illuminance, uniformity, and efficiency of different forms of lighting used in basketball court illumination.

We simulate and compare the illuminance, uniformity, and efficiency of metal-halide lamps, white LED light sources, and hybrid light box designs combining sunlight and white LED lighting used for indoor basketball court illumination. According to the optical simulation results and our examination of real situations, we find that hybrid light box designs combining sunlight and white LEDs do perform better than either metal-halide lamps or white LED lights. An evaluation of the sunlight concentrator system used in our inverted solar cell shows that the energy consumption of stadium lighting can be reduced significantly.