Principle of the Bangming Machinery Evaporator Circulation Pump

The evaporator circulation pump is an important component of the evaporator. It consists of a motor, volute, impeller, and drive shaft. Motors come in two types: DC and AC. DC motors primarily provide power to the evaporator, while AC motors deliver refrigerant.

Both belong to power electronic devices, with similar working principles and voltage and current regulation capabilities. They can alter the output characteristics of electrical energy (power density, frequency, etc.). However, DC fans can cool the evaporator, while variable frequency fans cannot. When the input voltage is greater than or equal to the rated voltage, the output current decreases; when the input voltage is less than the rated voltage, the input current increases.

Below is a brief introduction to the structure and working principle of the two types of motors.

The structure of a DC motor is relatively simple, consisting of a stator (motor) and several armatures. The stator drives the rotating magnetic field in a reciprocating motion; the armature is an electromagnetic switching component that generates a rotating magnetic field. It consists of a rotor (or stator core), stator windings, and permanent magnetic materials.

They can be classified as series or parallel connections depending on how the motor and armature windings are connected.

A series connection refers to a method where the motor is directly connected to the armature windings to form a circuit and then connected to the armature terminal; a parallel connection means the motor and armature terminal are connected in parallel.

In practice, the two can be connected in series to form a single device, which has certain advantages.

However, due to some problems and limitations inherent in the series structure, the parallel structure often leads to more problems and defects; while a series-parallel combination may cause damage to some coils in the armature windings, affecting the overall service life of the equipment.

We know that the stator windings of a motor directly connected to the motor in a loop are generated by the magnetic field produced by itself, resulting in attractive and repulsive forces; while the armature winding coils are generated by the magnetic field formed between them and the coils.

If some parts of the stator are damaged or there are a certain number of coils of poor quality, the entire equipment will not operate normally; while a series-parallel combination can improve the normal operation of the entire equipment when the motor and motor generate mutual forces (but the current will also increase).

The two methods can be combined to form a single device for use, so generally the following conditions must be met: 1. Variable frequency start-up function is required in actual use; 2. A variable frequency speed control motor and a matching variable frequency drive are required.