電加熱器是指利用電能達(dá)到加熱效果的電器，按加熱方式的種類來區(qū)分，大致可分為三類:

  1、電磁加熱-電磁加熱是通過電子線路板組成部分產(chǎn)生交變磁場、當(dāng)用含鐵質(zhì)容器放置上面時(shí)，容器表面具切割交變磁力線而在容器底部金屬部分產(chǎn)生交變的電流(即旋渦)，渦流使容器底部的鐵原子高速無規(guī)則運(yùn)動(dòng)，原子互相碰撞、摩擦產(chǎn)生熱能，從而起到加熱物品的效果。因?yàn)槭氰F制容器自身發(fā)熱，所以熱轉(zhuǎn)化率特別高，最高可達(dá)到95%.電磁爐、電磁灶都是采用的電磁加熱技術(shù)。

  2、紅外線加熱--紅外線的傳熱形式是輻射傳熱，由電磁波傳遞能量。在遠(yuǎn)紅外線照射到被加熱的物體時(shí)，一部分射線被反射回來，一部分被穿透過去。當(dāng)發(fā)射的遠(yuǎn)紅外線波長和被加熱物體的吸收波長一致時(shí)，被加熱的物體吸收遠(yuǎn)紅外線，這是物體內(nèi)部分子和原子發(fā)生共振--產(chǎn)生強(qiáng)烈的振動(dòng)、旋轉(zhuǎn)，而共振和旋轉(zhuǎn)使物體溫度深高，達(dá)到了加熱的目的。

  3、電阻加熱--利用電流通過電熱體放出熱量來加熱坯料的加熱方法。常見的電阻絲加熱，陶瓷加熱器以及電阻圈加熱，石英管加熱，原理上都屬于電阻式加熱。

  三種加熱方式的對(duì)比:

  1、電阻式加熱器的加熱是最原始的，所以熱效率也是最差的，通常熱效率只有百分之七十左右，大量的熱能散發(fā)到空氣中。

  2、紅外線的加熱方式相比電阻要好一點(diǎn)，但是依然大量的熱量散發(fā)到空氣中，只不過紅外線本身散發(fā)到空氣中的，而是被加熱的物體把熱量散發(fā)到空氣中。

  3、電磁加熱器工作時(shí)是有一層保溫層把受熱物體包裹住的，然后磁場透過保溫層直接加熱物體本身，所以熱效率是最高的幾乎熱能沒有流失，其效率超過95%以上，而且電磁加熱器是被加熱物體自身發(fā)熱所以也沒有熱傳遞的損失，整體節(jié)能是同等條件下電阻加熱30%-70%，紅外線加熱器因?yàn)槠浼訜崽攸c(diǎn)無法和電磁加熱做詳細(xì)比較，但散發(fā)出的溫度上來計(jì)算，同等條件下應(yīng)該電磁加熱比紅外線加熱節(jié)省能源在20%以上

  Electric heaters refer to electrical appliances that use electric energy to achieve heating effects. They can be roughly divided into three categories according to the types of heating methods:
  1. Electromagnetic heating - electromagnetic heating generates an alternating magnetic field through electronic circuit board components. When an iron containing container is placed on it, the surface of the container cuts the alternating magnetic line of force and generates an alternating current (i.e. vortex) at the metal part at the bottom of the container. The vortex makes the iron atoms at the bottom of the container move irregularly at high speed, and the atoms collide and rub with each other to generate heat energy, thus heating articles. Because the iron container heats itself, the heat conversion rate is particularly high, up to 95%. The induction cooker and the induction cooker all use electromagnetic heating technology.
  2. Infrared heating -- The heat transfer form of infrared is radiation heat transfer, which transfers energy by electromagnetic waves. When the far infrared ray shines on the heated object, part of the ray is reflected back and part is penetrated. When the wavelength of the far infrared ray emitted is consistent with the absorption wavelength of the heated object, the heated object absorbs the far infrared ray. This is because the molecules and atoms inside the object resonate - generating strong vibration and rotation, which makes the object temperature deep and high, thus achieving the purpose of heating.
  3. Resistance heating -- A heating method that uses the current to release heat through the electric heater to heat the blank. Common resistance wire heating, ceramic heater and resistance coil heating, and quartz tube heating are all resistance heating in principle.
Comparison of three heating methods:
  1. The heating of resistance heater is the most primitive, so the thermal efficiency is also the worst. Generally, the thermal efficiency is only about 70%, and a large amount of heat energy is emitted into the air.
  2. The infrared heating method is better than the resistance, but still a lot of heat is emitted into the air. Only the infrared itself is emitted into the air, but the heated object emits heat into the air.
  3. When the electromagnetic heater works, it has a thermal insulation layer to wrap the heated object, and then the magnetic field directly heats the object itself through the thermal insulation layer, so the thermal efficiency is the highest, almost no heat loss, and its efficiency exceeds 95%. Moreover, the electromagnetic heater is heated by the heated object itself, so there is no heat transfer loss. The overall energy saving is 30% - 70% of resistance heating under the same conditions, The infrared heater cannot be compared with electromagnetic heating in detail due to its heating characteristics, but the temperature emitted can be calculated. Under the same conditions, electromagnetic heating should save more than 20% energy than infrared heating