How to adjust the temperature of well type furnace?

The temperature control system is mainly composed of four parts: temperature sensor, temperature regulator, executive device and controlled object, and its system structure diagram. The controlled object is the temperature object of the electric furnace with large capacity and large inertia, which is a typical multi-step volume delay characteristic. In engineering, it is often approximated to a second-order volume delay with pure delay; Due to the large capacitance of the controlled object, heat treated silicon controlled rectifier is usually used as the actuator of the regulator.

Characteristics of the actuator: the temperature regulation of the electric furnace changes the ratio of the closing time Tb to the opening time Tk of the electric furnace wire through the intermittent action of the regulator (power supply energy) α,α= Tb/Tk。

In industry, regulating the temperature of well type furnace is to adjust the average AC voltage at both ends of the load, that is, the load power, by switching on and off several cycles of the circuit within the set cycle range, and changing the ratio of thyristor on and off time within the set cycle, which is commonly referred to as the power regulator or cycle controller; The power regulator triggers the thyristor to turn on when the power supply voltage crosses zero, so what the load gets is a complete sine wave, and what it regulates is only the voltage cycle that is turned on within the set period Tc. If the wave number of the conduction cycle in the cycle Tc is n, and the cycle of each cycle is T, then the output power of the power regulator is P=n × T × Pn/Tc, Pn is the output power of the device when the voltage in the set cycle Tc passes through completely.