Electric fan (electric appliance)
Electric fan, also known as fan and electric fan, is a kind of household appliance that uses motor to drive fan blades to rotate to accelerate air circulation. Mainly used for cooling summer heat and circulating air. Widely used in homes, classrooms, offices, shops, hospitals and hotels.
The electric fan is mainly composed of fan head, blades, mesh cover and control device. The fan head comprises a motor, a front end cover, a rear end cover and a shaking head air supply mechanism. The main components of the electric fan are: AC motor. Its working principle is that the electrified coil is forced to rotate in the magnetic field. When electric energy is converted into mechanical energy, due to the existence of coil resistance, it is inevitable that some electric energy will be converted into heat energy.
Common household electric fans are essentially axial fans, that is, the direction of the wind is parallel to the rotation axis of the fan blades.
principle of operation
The main components of the electric fan are: AC motor. Its working principle [1] is that the electrified coil is forced to rotate in a magnetic field. When electric energy is converted into mechanical energy, due to the existence of coil resistance, it is inevitable that some electric energy will be converted into heat energy. In addition, low-power motors such as DC motors and DC brushless motors are more and more widely used in small electric fans.
When the electric fan is working (assuming that there is no heat transfer between indoor and outdoor), the indoor temperature will not decrease, but will increase. Let's analyze the reasons for the temperature rise: when the electric fan is working, because there is current passing through the coil of the electric fan, the wires are resistive, which will inevitably give off heat and the temperature will naturally rise. But why do people feel cold? Because there is a lot of sweat on the surface of human body, indoor air will flow when the electric fan works, so it can promote the rapid evaporation of sweat, and "evaporation needs to absorb a lot of heat", people will feel cool.
structure
Rotor: composed of magnets, blades and shafts;
Stator: composed of silicon steel sheet, spool and bearing;
Control circuit: IC induction magnet; The N.S. pole controls the conduction of its coil through the circuit, generates internal excitation and makes the rotor rotate.
kind
1. According to the motor structure, it can be divided into single-phase capacitive, single-phase shaded pole, three-phase induction, DC and AC/DC series commutator fans.
According to the use, it can be divided into: household electric fan and industrial exhaust fan.
(1) Household electric fans: ceiling fans, desk fans, floor fans, wall fans, ceiling fans, ventilation fans, box fans, air-conditioning fans (i.e. air coolers), etc. Some shake their heads, some don't shake their heads, and some are box fans; Some floor fans shake their heads and turn pages. There is also a small wind electric fan, which is specially hung in the mosquito net. When you sleep at night in summer, the breeze blows gently as soon as you turn it on, so that you can sleep well and not get sick.
(2) Industrial exhaust fan: mainly used for forced air convection.