Thermal Performance of Domestic Replacement A19 LED Lighting Products

2016 ◽  
Author(s):  
Thomas Storey ◽  
Robin Rackerby ◽  
Heather Dillon ◽  
Lydia Gingerich
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Dissipation ◽  
Cooling System ◽  
Light Emitting Diode ◽  
Research Process ◽  
Light Emitting ◽  
Led Lighting ◽  
Proper Design ◽  
The Cost

In an effort to create a Light Emitting Diode (LED) lighting system that is as efficient as possible, the heat dissipation system must be accurately measured for proper design and operation. Because LED lighting technology is new, little optimization has been performed on typical cooling system required for most A19 replacement products. This paper describes the research process for evaluating the thermal performance of over 15 LED lighting products and compares their performance to traditional lighting sources, namely incandescent and compact fluorescent (CFL). This process uses radiation and convection to model typical cooling mechanisms for domestic A19 type replacement LED products. The A19 products selected for this investigation had input wattages ranging between 7 to 60 Watts, with outputs ranging from 450 to 1100 lumens. The average LED tested dissipated 43% (± 5%) of the total heat generated in the lighting product through the heat exchanger. The best thermal performance was observed in an LED product that dissipated approximately 58% of the total product heat through the heat exchanger. Results indicate that significant improvements to the current LED heat exchanger designs are possible, which will help lower the cost of future LED products, improve performance, and reduce the environmental footprint of the products.

Thermal Performance Evaluation and Economic Analysis of LED Integrated with Thermoelectric Cooler Package

2011 ◽  
Vol 216 ◽  
pp. 106-110 ◽  
Author(s):  
Hong Qin ◽  
Da Liang Zhong ◽  
Chang Hong Wang
Keyword(s):  
Economic Analysis ◽  
Thermal Performance ◽  
Power Dissipation ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Vital Role ◽  
Junction Temperature ◽  
Total Power ◽  
Thermoelectric Cooler ◽  
Light Emitting

Thermal management is an important issue for light emitting diodes’ utilization. For high power light emitting diode (LED), active heat dissipation method plays a vital role. As a new cooling device, thermoelectric cooler (TEC) is applied in LED packaging for the precisely temperature controlled advantage. In order to evaluate the thermal performance of the TEC packaging designs in LED, experimental measurement is used to assess the chip’s junction temperature of three different cooling models, which include the heatsink model, the heatsink and fan model and the TEC, heatsink and fan model. Based on the research, it is better to apply TEC cooling methods with the power dissipation of LED less than 35 W and the wind speed is 3.6 m/s. However, the power dissipation of TEC itself plays a vital role of the total power dissipation of LED packaging. The results of economic analysis shows that the LED integrated with TEC package achieves 22.34% and 44.73% electric energy saving under the condition of 20 W and 30 W power dissipation of the LED chip contrasts to the fluorescent lamp, but sacrifices 2.71% electric power under the condition of 10 W power dissipation of the LED chip.

scholarly journals Thermal Performance of LED Filament in Flip-Chip Packaging Manufactured for Different Correlated Color Temperature

2021 ◽  
Vol 11 (19) ◽  
pp. 8844
Author(s):  
He Jiang ◽  
Jiming Sa ◽  
Cong Fan ◽  
Yiwen Zhou ◽  
Hanwen Gu ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Flip Chip ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Color Difference ◽  
Junction Temperature ◽  
Color Temperature ◽  
Constant Current ◽  
Light Emitting ◽  
Flip Chip Packaging

The effect of correlated color temperature (CCT) on the thermal performance of light emitting diode (LED) filament in flip-chip packaging was investigated in detail. Two filaments with different lengths were selected as the research object, and the thermal resistance of filaments under three CCT (2200 K, 2400 K, 2700 K) were studied. The optical properties and thermal parameters of the two groups of filaments were measured, and the results were analyzed combined with the color coordinate. The experimental results show that thermal properties of LED filaments is closely related to CCT. Under constant current condition, junction temperature decreases with the increase of color difference. With the change of phosphor glue and phosphorus powder ratio, the color temperature of LED filament also changes. In the filaments with the same chip structure and packaging mechanism, the higher the proportion of red phosphorescent powder, the worse the heat dissipation performance of the filament. These results show that in the design and manufacture of LED filament, it is helpful to control the CCT of LED filament under the premise of meeting the use requirements.

Thermal Management for High Power Light-Emitting Diode Street Lamp

2010 ◽  
Author(s):  
M. Ying ◽  
S. M. L. Nai ◽  
P. Shi ◽  
J. Wei ◽  
C. K. Cheng ◽  
...  
Keyword(s):  
Thermal Management ◽  
Thermal Performance ◽  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
System Level ◽  
Light Emitting ◽  
High Power Led ◽  
Street Lamp ◽  
Lamp System

Light-emitting diode (LED) street lamp has gained its acceptance rapidly in the lighting system as one of choices for low power consumption, high reliability, dimmability, high operation hours, and good color rendering applications. However, as the LED chip temperature strongly affects the optical extraction and the reliability of the LED lamps, LED street lamp performance is heavily relied on a successful thermal management, especially when applications require LED street lamp to operate at high power and hash environment to obtain the desired brightness. As such, a well-designed thermal management, which can lower the LED chip operation temperature, becomes one of the necessities when developing LED street lamp system. The current study developed an effective heat dissipation method for the high power LED street lamp with the consideration of design for manufacturability. Different manufacturable structure designs were proposed for the high power street lamp. The thermal contact conductance between aluminum interfaces was measured in order to provide the system assembly guidelines. The module level thermal performance was also investigated with thermocouples. In addition, finite element (FE) models were established for the temperature simulation of both the module and lamp system. The coefficient of natural convection of the heat sink surface was determined by the correlation of the measurement and simulation results. The system level FE model was employed to optimize and verify the heat dissipation concepts numerically. An optimized structure design and prototype has shown that the high power LED street lamp system can meet the thermal performance requirements.

Application of Micro-Tube Water-Cooling Device for the Improvement of Heat Management in Mixed White Light Emitting Diode Modules

2011 ◽  
Vol 308-310 ◽  
pp. 2422-2427 ◽  
Author(s):  
Maw Tyan Sheen ◽  
Ming Der Jean ◽  
Yu Tsun Lai
Keyword(s):  
Thermal Management ◽  
White Light ◽  
Heat Dissipation ◽  
Cooling System ◽  
Light Emitting Diode ◽  
Thermal Dissipation ◽  
Water Cooling ◽  
Cooling Device ◽  
Heat Management ◽  
Light Emitting

This paper introduces a module using the RGB-based LED design to improve the thermal management of a mixied white light LED and describes a system for heat dissipation in illuminated, high-power LED arrays. Mixed light LEDs can be produced by combining appropriate amounts of light from the red, green and blue LEDs in an array. A LED cooling system, using a micro- tube water-cooling device, was fabricated. Recycling water in the system, gave more efficient convection and the heat created by the LEDs was easily removed, in the experiments. It was shown that micro-tube water-cooling systems rendered an improvement in thermal management that effectively decreases the thermal resistance and provides very good thermal dissipation. Furthermore, the results of experiment and simulation demonstrated that a micro-tube water-cooling system is very effective in heat dissipation in LEDs and the fabrication of practical micro-water tube cooling devices for mixing light LEDs was feasible and useful

Design of Photovoltaic Panel-Light-Emitting Diode Spotlight and Its Performance Analysis in Tunnel Buildings

2021 ◽  
Vol 16 (7) ◽  
pp. 1067-1074
Author(s):  
Guangjun Zhang ◽  
Min Yuan ◽  
Zheng Wang
Keyword(s):  
Light Intensity ◽  
Output Voltage ◽  
Light Emitting Diode ◽  
Spectral Irradiance ◽  
Photovoltaic Panel ◽  
Light Emitting ◽  
Led Lighting ◽  
Lighting Device ◽  
Detection Circuit ◽  
The Cost

According to the adaptive characteristics of the entrance and exit sections of tunnel buildings with the intensity of external sunlight, the cost of traditional photovoltaic panel (PV)-light-emitting diode (LED) lighting system increases due to battery. Combined with the structure of sunshine conveyor, a new PV-LED spotlight is proposed. The lighting device uses PV module as the power supply to directly drive the LED light source, which can make the brightness of the tunnel synchronized with the sunlight intensity, avoid the problem that it cannot work stably due to its weather changes, and further save the cost without battery. The main control chip adopts STC12C5A60S2 and supports multiple 10-bits precision A/D conversion channels. It can process the output signal of the light intensity detection circuit and set a threshold circuit to judge the intensity of sunlight, further control the working state of LED lighting device. The LED display module adopts 12864 liquid crystal display (LCD) with built-in T6963C driver to display five kinds of data, including the output voltage of light intensity detection circuit and the corresponding voltage value of four threshold circuits. The circuit resistance can be adjusted to change the light output voltage threshold required by the tunnel. In the test, the PV-LED lighting device is erected in the tunnel building. Compared with the traditional PV-LED lighting device and the new PV-LED spotlight designed, the new PV-LED lighting device in the morning and evening can further improve the efficiency of solar power generation. Meanwhile, the PV plate plane of the designed lighting device is perpendicular to the plane where the sunlight shines. The spectral irradiance and full band spectral irradiance of the lighting device in six bands was calculated and found that the percentage of spectral irradiance in different bands is close to the percentage requirement under AM1.5.

Ensuring Effective Heat Dissipation in the Design of Light Emitting Diode (LED) Lighting Equipment

2021 ◽  
pp. 80-88
Author(s):  
Vadim Alekseevich Chernyshov ◽  
Evgeny Aleksandrovich Pechagin ◽  
Oleg Borisovich Gladkov ◽  
Roman Pavlovich Belikov ◽  
Nailya Kamilevna Miftakhova
Keyword(s):  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Led Lighting ◽  
Effective Heat

A three-dimensional thermal analysis for cooling a square Light Emitting Diode by Multiwalled Carbon Nanotube-nanofluid-filled in a rectangular microchannel

2021 ◽  
Vol 13 (11) ◽  
pp. 168781402110599
Author(s):  
Mohamed Bechir Ben Hamida ◽  
Mohammed A. Almeshaal ◽  
Khalil Hajlaoui
Keyword(s):  
Heat Sink ◽  
Heat Dissipation ◽  
Cooling System ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Junction Temperature ◽  
Engine Oil ◽  
Inlet Temperature ◽  
Rectangular Microchannel ◽  
Light Emitting

The aim of this paper is to ensure proper thermal management in order to remove and dissipate the heat produced by a square Light Emitting Diode (LED), as well as to ensure stable and safe operation by reducing the junction temperature. For this, we developed a three-dimensional code, time-dependent that solves the systems of equations for the mass, momentum, and energy using Comsol Multiphysics. After validation of this numerical 3D code, the thermal performance of a LED cooling system with three nanofluids such as MWCNT-Water, MWCNT-Ethylene Glycol, and MWCNT-Engine oil is studied numerically into account of aggregation effect. Several parameters such as: the power of the LED lamp, the inlet temperature and velocity of nanofluid, the length of the heat sink, and the length of the microchannel have been varied in order to find an optimal condition allowing a good heat dissipation from the LED chip to the heat sink. It was concluded that the use of MWCNT-Water in the microchannel is the best nanofluid that can cool the heat sink. In addition, the increase of velocity inlet of the coolant in the microchannel, the length of the heat sink, and the microchannel length while the decrease of the inlet temperature of nanofluid in the microchannel are an important factors allowing the decrease of the junction temperature of the square LED lamp.

scholarly journals Methods of Disinfecting Stethoscopes: Systematic Review

2020 ◽  
Vol 17 (6) ◽  
pp. 1856 ◽  
Author(s):  
Margherita Napolitani ◽  
Daiana Bezzini ◽  
Fulvio Moirano ◽  
Corrado Bedogni ◽  
Gabriele Messina
Keyword(s):  
Systematic Review ◽  
English Language ◽  
Light Emitting Diode ◽  
Bacterial Load ◽  
Silver Ions ◽  
Light Emitting ◽  
Disinfection Methods ◽  
Mesh Terms ◽  
Healthcare Associated ◽  
The Cost

The aim of this systematic review was to investigate the effectiveness of various disinfection methods available for stethoscopes. In March 2019, we performed a search in PubMed and Scopus using the search terms: “reducing stethoscopes contamination” and “disinfection stethoscopes”; the Mesh terms used in PubMed were “Decontamination/methods” or “Disinfection/methods” and “Stethoscopes/microbiology”. Selection criteria were: English language; at least one disinfection method tested. A total of 253 publications were screened. After title, abstract, and full-text analysis, 17 papers were included in the systematic review. Ethanol at 90%, Ethanol-Based Hands Sanitizer (EBHS), triclosan, chlorhexidine, isopropyl alcohol, 66% ethyl alcohol, sodium hypochlorite, and benzalkonium chloride have been proven to lower the presence of bacteria on stethoscopes’ surfaces. In addition, alcohol wipes show effective results. A wearable device emitting ultraviolet C by Light-Emitting Diode (LED) resulted efficacious against common microorganisms involved in Healthcare Associated Infections. The cover impregnated with silver ions seemed to be associated with significantly higher colony counts. Instead, copper stethoscopes surface reduced bacterial load. The disinfection of stethoscopes appears to be essential. There are many valid methods available; the choice depends on various factors, such as the cost, availability, and practicality.

Reliability of High-Power Light Emitting Diode Attached With Different Thermal Interface Materials

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Xin Li ◽  
Xu Chen ◽  
Guo-Quan Lu
Keyword(s):  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Temperature Cycling ◽  
Fluorescent Light ◽  
Light Sources ◽  
Light Emitting ◽  
Die Attach ◽  
Nanosilver Paste ◽  
Interconnection Material

As a solid electroluminescent source, white light emitting diode (LED) has entered a practical stage and become an alternative to replace incandescent and fluorescent light sources. However, due to the increasing integration and miniaturization of LED chips, heat flux inside the chip is also increasing, which puts the packaging into the position to meet higher requirements of heat dissipation. In this study, a new interconnection material—nanosilver paste is used for the LED chip packaging to pursue a better optical performance, since high thermal conductivity of this material can help improve the efficiency of heat dissipation for the LED chip. The bonding ability of this new die-attach material is evaluated by their bonding strength. Moreover, high-power LED modules connected with nanosilver paste, Sn3Ag0.5Cu solder, and silver epoxy are aged under hygrothermal aging and temperature cycling tests. The performances of these LED modules are tested at different aging time. The results show that LED modules sintered with nanosilver paste have the best performance and stability.

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