Comparative analysis of HID lamp and LED lamp

HID lamp is the general name of high-pressure gas discharge lamp, which is abbreviated as HID (high intensity discharge). It generates strong light through arc discharge in the lamp tube, and then combines with inert gas or metal vapor filled in the lamp tube. The LED lamp is a lamp product developed by using the principle of LED.

Basic introduction and characteristic comparison of two products

HID Lights

HID lamp at present, high pressure sodium lamp, (fluorescent) high pressure mercury lamp, xenon lamp and metal halide lamp all belong to hid lamp. They all have similar characteristics. Xenon lamp and metal halide lamp are developed recently on the basis of the former two kinds of lamps. Therefore, metal halide lamp is taken as the representative of HID lamp and compared with LED lamp.

Metal halide lamp is a kind of discharge lamp which works by AC power supply and produces arc discharge light in the mixed vapor of mercury and rare metal halides. Metal halide lamp is the third generation light source made by adding various metal halides on the basis of high pressure mercury lamp.

Metal halide lamp has the characteristics of high luminous efficiency (65 ~ 140lm / W), long life (5000 ~ 20000h), good color rendering (ra65 ~ 95), compact structure and stable performance. It has the advantages of fluorescent lamp, high pressure mercury lamp and high pressure sodium lamp, overcomes the defects of these lamps, and integrates the main advantages of gas discharge light source.

In particular, the advantages of high luminous efficiency, long service life and good light color make the metal halide lamp develop rapidly and more widely. The metal halide lamps on the market are the same as other gas discharge lamps. Mercury and metal halides are contained in the fillings in the lamps. Some of these substances are toxic. If they are not handled carefully, they will pollute the production environment and damage the health of workers. When the arc tube exhausts, there is a trace of mercury vapor, If it is not handled properly, it will be directly discharged into the atmosphere.

When the lamp is damaged, it will pollute the environment. But it is a kind of new energy-saving light source which is closest to the sunlight color. It is widely used in the lighting of stadiums, exhibition centers, large shopping malls, industrial plants, streets, squares, stations, docks and other places.

 

LED Lights

LED (Light Emitting Diode) is a solid-state semiconductor device that can directly convert electrical energy into light. Initially, LEDs were used as indicator light sources for instrumentation. Later, LEDs of various colors were widely used in traffic signal lights and large-area display screens, which produced good economic and social benefits. Ordinary LED lights can only emit monochromatic light. For lighting, people need more white light sources.

In 1998, the white LED was successfully developed. LED light source has the advantages of low-voltage power supply, low energy consumption, strong applicability, high stability, short response time, no pollution to the environment, multi-color lighting, etc., but the price is more expensive than existing lighting equipment. Especially for high-power LED lighting, scientific research and development must be strengthened in this regard.

Comparison of HID lamp and LED lamp

No.	Characteristics	HID Light	LED Light
1	Color rendering	<80	>80
2	Price	low	high
3	luminous attenuation (3000 H)	10%	<5%
4	Heat Generated	High	Low
5	Matching of lamps	Easy	Difficult
6	apply	Low Wattage	High Wattage
7	Lamp standard	More unified	Not unified
8	Light source characteristics	Bright and not dazzling	The light beam is concentrated and dazzling
9	Lifespan  (H)	12,000	50,000
10	Environmental protection / earthquake resistance	N	Y
11	Starting speed	Low	Quick
12	Stroboscopic	Y	N
13	Energy consumption	100	50
14	illumination	18.22	23.55
15	Applicable place	Roads, squares, factories, etc	Decorative lighting, display lighting, signal light, etc.,

 

Analysis of lamp Market Development

From the development history of lamp market, the development trend in recent years is as follows:

Incandescent lamp==> high pressure mercury lamp==> high pressure sodium lamp==> and metal halide lamp==> LED lights.

Starting from the high-pressure mercury lamp, the following lamps are all high-pressure gas discharge lamps with similar principles, so the lamp production standards are relatively unified and easy to replace. Therefore, the high-pressure gas discharge lamps still occupy a dominant position, especially in the high-power lamps. However, in recent years, LED lamps have developed rapidly, especially in the decorative lighting, display lighting, signal lights and other low-power aspects.

Due to the high heat-dissipation value of LED in high power, high price, color rendering and matching of lamps and lanterns, it is still unable to compete with high-pressure gas discharge for at least 5-10 years. High pressure gas discharge lamps have great development space in this part of the market , especially xenon lamps, metal halide lamps and other new lamps and lanterns.

Current HID lamp manufacturers

Currently, HID lamp manufacturers are still dominated by three foreign brands, namely Osram of Germany, Philips of the Netherlands and GE of the United States. All three companies have production bases in China, and even some product models are OEM production. There are currently three well-known lighting companies in China, namely Dezhou Lighting Company, Enlightenment Lighting Company and Changming Lighting Company.

Attention should be paid to the technical difficulties in HID production

1. Ceramic shell arc tube

The material of arc tube shell is polycrystalline alumina ceramic, which is commonly known as sapphire. This kind of ceramic has moderate density but high hardness. The arc tube shell made of this kind of ceramic is light and firm; Alumina crystal has high transmittance, the total transmittance is 96% ~ 98%; the crystal has high thermal conductivity, uniform shell temperature distribution, strong thermal shock resistance and weak cold end effect; the working substance vapor density in the arc tube is high, and the ionization excitation intensity is high, so it has high luminous efficiency, good color rendering and stable performance.

 

Due to the gap between domestic and foreign chemical preparation process, the quality of high-purity aluminum oxide powder has a gap with foreign imported products. Therefore, in order to make good arc tube, it is necessary to import high-purity aluminum oxide powder. In addition, in the process of manufacturing arc tube, the structure design and production process parameters of arc tube need to be strictly controlled. In addition to the above, there are patent restrictions of the three giants.

2. The filler in the arc tube is commonly known as “pill” in the industry

According to their functions, the pill composition of metal halide lamp fillers can be divided into two categories: one can contract the arc (such as thorium, scandium and rare earth metals); the other can expand the arc (such as indium, thallium and alkali metals). In a word, pill is a mixture which can improve the light efficiency and color rendering of light source.

Because the process conditions of domestic pills can not meet the requirements, the proportion of ingredients or purity of the pills are not very good, so the insiders suggest to buy the products from APL company of the United States or South Korea.

Summary and suggestions

From the current lighting industry, the development of a new generation of HID lamps and lanterns is still very promising. Although LED is a new lighting technology and has made great progress in decorative lighting, there are still many problems to be solved in factories, mines, squares, roads and other high-power lighting. Therefore, HID lamps and lanterns will still occupy a dominant position in the market in 2-3 years .