High efficiency radiator in the field of LED lighting


High-power LED lighting fixtures generate more heat during operation, and heat is required to be remitted through the heat sink and distributed to the environment. This paper systematically introduces the characteristics of various main radiators, and analyzes and introduces the material performance characteristics.
LED (short for Light-emitting Diode) lighting refers to a new type of environmentally friendly lighting products using semiconductor light-emitting diode technology as a light source. LED lighting has the characteristics of energy saving, easy control, maintenance-free, safe and environmentally friendly, and long service life. Its service life can reach 50,000-100,000 hours, far exceeding 1,000 hours of traditional tungsten light bulbs and 10,000 hours of fluorescent tubes. . As a new type of energy-saving and environmentally-friendly green light source, LED has a very promising application prospect. However, most of the electric energy needs to be converted into heat energy when the LED is illuminated at work. If the heat cannot be dissipated in time, the junction temperature of the LED will continue to be constant. The rise, when the LED junction temperature exceeds a certain limit, irreversible light decay will occur, resulting in reduced or even damaged LED operating life. Therefore, LED lamps need a heat sink to dissipate the heat generated by themselves to work properly.
1. General lighting high-power LED lamps (1W or more) Introduction 1. Common types of bulbs, spotlights, candle lights, tube lights, ceiling lamps, street lamps, lights, etc., and depending on the interface specifications, there are many models (partial The luminaire samples are shown in Figure 1).
The basic structure of LED lighting includes three parts. A: Light source structure: LED light board includes illuminant, LEDPCB board, etc. B: LED drive power can be divided into isolated power supply and non-isolated power supply; C: LED heat dissipation, Astigmatism or light guide components: including LED heat sinks, LED shades or LED light guides. Its basic is shown in Figure 2.
2. LED high-efficiency safety heat sink working principle The main function of the heat sink is to continuously remit the heat generated by the LED chip work and distribute it to the environment, so that the temperature of the wafer is kept within the required range, thus ensuring that the LED light can normal work. The heat generated from the LED chip is mainly transmitted through the LED package structure, the circuit board, and the heat dissipation structure of the lamp in a heat conduction manner, and finally the heat is transferred from the heat dissipation structure to the environment by convection (thermal convection and heat conduction) and heat radiation. The common LED heat sink cooling mode is shown in the figure.
The quality of the heat sink depends mainly on the thermal resistance of the heat sink under the conditions of safety. The smaller the thermal resistance, the lower the junction temperature of the LED lamp under the same conditions, and the lower the junction temperature of the LED, the longer the life of the wafer will be. The thermal resistance of the heat sink should include the thermal resistance and the thermal resistance. For a certain shape of the heat sink, the thermal resistance is mainly related to the thermal conductivity of the heat sink material. The larger the thermal conductivity, the smaller the thermal resistance and the better the thermal conductivity. Under certain environmental conditions, the thermal resistance depends mainly on the heat dissipation. The heat dissipation area of ​​the device and the radiation coefficient of the surface material of the heat sink, the larger the heat dissipation area, the higher the radiation coefficient, the smaller the heat dissipation resistance, and the better the heat dissipation effect.
III. Common LED Radiator Different Materials Introduction The so-called LED heat sink is a component that can quickly remit and generate heat generated in the operation of the LED chip to the environment. Therefore, it is not acceptable to have only a certain heat dissipation area as a heat sink. The material used to make the heat sink must have a certain thermal conductivity, that is, to have a high thermal conductivity, so that the heat generated by the wafer can be continuously recirculated and finally dispersed into the environment; of course, for the heat conductive material, in addition to thermal conductivity. It should also have the characteristics of small proportion, low price, high strength and easy processing.
Commonly used materials usually include metal materials, inorganic non-metal materials and polymer materials. Among them, polymer materials include plastics, rubber, and chemical fibers. The thermally conductive material is typically a metal and a partially inorganic non-metallic material. Among the common metals, the thermal conductivity of aluminum and copper is relatively high, but the price of copper is high, the ratio is large, the processability is not as good as aluminum, and the aluminum heat sink can fully meet the requirements of LED heat dissipation, so aluminum in the LED metal heat sink The main heat sink is the main one, and the copper heat sink is rare. In addition, a small number of radiators are iron. Inorganic non-metallic materials with good thermal conductivity are generally powdery before processing, and need to be processed by special processes. After processing into a heat sink, they are basically ceramic; some inorganic non-metallic materials have high thermal conductivity and are very insulating, but the price is very high. Such as diamond, boron nitride, aluminum nitride, etc.; although some have high thermal conductivity but are not insulated, similar to metals such as graphite, carbon fiber, etc.; and it is very difficult to process inorganic non-metallic powder into a ceramic radiator of complex shape. Therefore, although ceramic LED heat sinks are used, they have great limitations and need to be further improved and improved. The thermal conductivity of the polymer material itself is relatively poor. However, if a metal powder or a non-metal powder having good thermal conductivity is added to a plastic or a rubber to form a heat conductive plastic or rubber, the thermal conductivity thereof is greatly improved. Because of its unique elasticity, thermal conductive rubber is irreplaceable by other thermal conductive materials, so it has been widely used in some fields, but it may not be suitable as a heat sink material because of its poor rigidity; thermal conductive plastic alone or with metal inserts The LED radiator manufactured by the company is a new generation of LED heat dissipation products recently developed. If properly designed, it can achieve the heat dissipation effect of the die-cast aluminum heat sink, and the outer surface is insulated and safer to use, which is the future development direction of the LED heat sink. The following is a brief introduction to several common LED heat sinks of different materials.
1. Aluminum radiators The most common LED radiators are aluminum radiators, which generally include die-cast aluminum and tensile aluminum radiators. The main reason is that metal aluminum has a high thermal conductivity, a small specific gravity, easy processing, and low price. Among them, die-cast aluminum radiator is the most commonly used, its thermal conductivity is 70-90W/mK, the appearance is more beautiful, the shape can be changed, the price is moderate; the disadvantage is that it is not insulated, for the safety needs to increase the insulation rubber or sleeve, and the insulation glue Or the sleeve is generally poorly heat-conducting, which is unfavorable for heat dissipation, and the cost is also increased. In addition, the cost of the die-cast aluminum radiator mold is high, which is not conducive to the development of new products; the production process needs to consume more energy, and the secondary processing cost is too large. The thermal conductivity of the stretched aluminum radiator is about 200W/mK, the heat conduction is very good, the processing cost is low at one time, but the secondary processing is often required, the secondary processing cost is high, and the form is relatively simple, and the insulation treatment is also required. For street lights and high power indoor LED lighting.
2. Thermally conductive plastic radiator The thermal conductive plastic LED lamp radiator developed by several large foreign companies not only solves the problem that the aluminum radiator itself is not insulated, but also the weight of the radiator is also reduced. At present, the company producing LED heat-dissipating plastics mainly includes DSM in the Netherlands, SABIC in Saudi Arabia, and Toray in Japan. The thermal conductive plastic is mainly composed of high-heat-resistant inorganic fillers such as nylon and PBT, such as aluminum nitride and boron nitride; its thermal conductivity is usually 5-15 times that of general-purpose plastics, generally only 1 -6W/mK or so. The main limitation of the existing industrialization of thermal conductive plastics is the high cost, the price is about 100-300 yuan / Kg, the price of the radiator is also higher than that of the die-cast aluminum radiator, although in some large companies producing LED lamps, such as Philips, etc. have certain applications, but in the near future, it is not possible to replace aluminum radiators in large quantities.
3.Thertrans thermally conductive composite radiator is a new type of LED heat sink that has received much attention in the market recently. It was independently developed by Shanghai Hefu New Material Technology Co., Ltd. Its heat dissipation performance is similar to that of a conventional metal heat sink, and it has electrical insulation properties similar to that of a heat conductive plastic. More outstanding performance is that it has very high-efficiency industrial molding performance, and can be used in low temperature processing molding technology (150 degrees) far lower than metal (600 degrees) and traditional thermal conductive plastics (260 degrees). Thertrans thermal conductive composite radiator It consists of Therpoxy thermally conductive composite and inlaid metal aluminum. The aluminum parts are made of stamped aluminum and have a thermal conductivity of 200W/mK or more. This aluminum-embedded composite heat sink has excellent heat dissipation and can be close to or equivalent to the heat dissipation effect of the die-cast aluminum heat sink, and the processing is relatively easy. From the test results (below), the heat dissipation effect of Thertrans composite heat sink can be close to that of the same shape die-cast aluminum heat sink, or the thermal resistance of the same shape of Thertrans thermal plastic heat sink and die-cast aluminum heat sink is basically the same.
In addition to the advantages of thermal conductivity and heat dissipation, Thertrans composite radiator has a beautiful appearance and a variety of styles. It can be molded by injection molding machine. Its weight is about one-third lower than that of the same shape die-cast aluminum radiator, and it does not need to add additional insulation treatment. Forming the threaded port and the like together with the heat sink effectively reduces the assembly process and cost of the LED lamp manufacturer.
Thertrans heat-conducting composite material used in Thertrans heat sink has a thermal conductivity of about 3W/mK. The price is only half of that of traditional high-performance thermal conductive plastic, or even less. The material has thermal conductivity, insulation, flame retardant, heat resistance, environmental protection and aging resistance. Easy to form, light weight and low price. Among them, the flame retardant can be achieved, it is in compliance with RoHS environmental protection requirements, and the surface breakdown voltage is more than 4000V. Therefore, it can better balance the performance and price problems in the industrialization process and is recognized by the market.

WS85 Skid Steer Loader 

General specifications of WS85 skid steer loader
Engine Mitsubisht S4S-DT
Rated power(kw) 62
Rated speed(rpm) 2500
External dimensions: length * width * high 3688*1817*2023(mm)
Operating weight(kg) with bucket 3867
Max travelspeed(km/h) 12
Performance
Rated operating capacity(kg) 1050
Tipping load(kg) 2100
Max.dump height(mm) 2543
Max.dump distance(mm) 652
Turn radlus,front tyre(mm)(without attachment) 1346
Wheel base(mm) 1179
Bucke capacity(m³) 0.52
Fuel tank capacity(m³) 88
Hydraulic oil tank capacity(m³) 70

WS85 Skid Steer LoaderWS85 Skid Steer Loader

WS85 Skid Steer Loader

Servo Control Configuration Table

Color Body Yellow Engine Mitsubisht S4S-DT
62KW/2500rpm
Operating Arm Yellow Bucket Auto Balance
Back Cover Yellow Control Joystick Control
Cab Black Quick-change Hanger Universal
Attachment Black Brake Motor With Brake
Cab Air conditioner Seat Safety Belt,
Heater Water-cooled engine Operating Bumper
Solid Tire 12x16.5
Fully enclosed drive cabin
Wiper Yes
Attachment Standard Bucket
Light Work Light Yes Horn Yes
Back-up Buzze Yes Accelerator Hands-feet
Double Control
Interior Light Yes Rear mirror Yes
Auxiliary Hydraulic Control Device G1 Output Fast Connection
G3/8 Oil-return Fast Connection
Hydraulic System Pistion Pump REXROTH Loader Body WS85
46cc
High Torque Motor POCLAIN Oil Tube 24°International Standard
398cc
Pilot Handle Italy HYDE Operating Arm Support Oil Cylinder Fixed Bracket
Gear Pump PERMCO 33cc Hydraulic oil flow rate 82.5L/min
Leveling Valve SAUER DANFOSS
Multi-way Valve Italy HYDE
Solenoid Valve SAUER DANFOSS
 


Ws85 Skid Steer Loader

Ws85 Skid Steer Loader,Ws85 Loader,Ws85 Wheel Loader

Shandong Zecheng CNC Machinery Co., Ltd , http://www.zccncmachinery.com