Osram LEDs in Coal Mine Lighting

Shenzhen General Technology use LED technology to reduce Energy, Maintenance and Accidents

Osram’s versatile Oslon SSL series are applied in Xishan Duerping coal mine lighting in Shanxi Province, the so-called “home of coal” in China. The 19,500 LEDs are installed in 975 lamps, replacing the traditional fluorescent lamps, to light up the 63.1 square km high wattage coal mine. They enable energy savings of 61% (from 427050 kilo Watt hour down to 170820 kilo Watt hour annually), as well as reduce maintenance requirements and accident rate significantly, resulting in an annual saving of more than RMB220,000 (around 28,000 EURO).

The underground coal mine is one of the most difficult lighting applications. It is a low reflectivity, low contrast, high temperature, and high corrosive environment. With the use of LEDs in place of traditional incandescent lamps, coal mine lighting application has become less challenging.

The 20W LED lamps come in two designs: – the round shape ones are for general lighting in the underground coal mine while the square ones are for long distance lighting inside the tunnels. Because of the low reflectivity in coal mines, the output of light sources needs to be much higher.  With luminous flux of 104 lm warm white to 130 lm cool white, Oslon SSL is the ideal choice for this application.

“We have chosen Osram’s Oslon SSL LEDs for their high reliability and efficiency,” said Zhong-hua Li, Chairman of the Board of Shenzhen General Technology Co. Ltd., the company which builds these coal mine lamps. “More importantly, the light output of these LEDs is high enough for good designs. The average luminance is 82Lx, compared to 45Lx of the previous incandescent lamps. With the use of advance optics, we are able to reduce glare to a minimum in this low contrast environment.”

Apart from high efficiency, these Oslon SSL LEDs excel in all the stringent tests for applications in the coal mine environment. They include the coal mine safety certification, explosion-proof certification, salt spray, waterproof testing, impact test and the 1000-hour burning test.

“The use of LEDs in coal mine lighting is definitely taking off,” said Kai-chong Cheng, Senior Marketing Director APAC of Osram Opto Semiconductors Asia Ltd.. “We are very pleased that our Oslon SSL LEDs are being chosen to be used in the coal province of China. These are the most compact 1 W LEDs on the market.  As LEDs do not use any glass envelope and cannot break, we hope the use of these LED lamps will reduce hazards for the people who work underground.”

LEDs are robust because they do not have a glass envelope or filament that can break. Besides, they can provide useful light in excess of 50,000 hours of operation as compared to about up to 3,000 hours for an incandescent bulb. The maintenance interval will be reduced from once in every three months to once a year. According to a study by the National Institute for Occupational Safety and Health (NIOSH) in the USA, the greatest percentage of accidents (53%) happened during the maintenance and repair work of light bulbs or light fixtures. The longer life and packaging (no glass envelope) of LEDs would decrease the exposure to these hazards.

ABOUT OSRAM OPTO SEMICONDUCTORS

OSRAM GmbH (Munich, Germany) is a wholly-owned subsidiary of Siemens AG and one of the two leading light manufacturers in the world. Its subsidiary, OSRAM Opto Semiconductors GmbH in Regensburg (Germany), offers its customers solutions based on semiconductor technology for lighting, sensor and visualization applications. Osram Opto Semiconductors has production sites in Regensburg (Germany) and Penang (Malaysia). Its headquarters for North America is in Sunnyvale (USA), and for Asia in Hong Kong. Osram Opto Semiconductors also has sales offices throughout the world. For more information go to www.osram-os.com.