(1) The temperature control system of the experimental chamber furnace is mainly composed of four parts: the temperature sensor, the temperature regulator, the actuator and the controlled object of the experimental electric furnace, which is also an important part of the temperature control system of the experimental electric furnace, and is designed and developed through its system structure diagram. The controlled object is the high-temperature furnace temperature object with large capacity and large inertia, which is a typical multi-order volume lag characteristic, which is often approximated as a second-order volume lag with pure hysteresis in engineering; Due to the large capacitance of the controlled object, thyristor is usually used as the actuator of the regulator.

(2) The characteristics of the actuator of the experimental chamber furnace: the temperature adjustment of the electric furnace is achieved by the regulator, changing the ratio of the closing time Tb of the electric furnace wire to the disconnection time Tk α, α=Tb/Tk, thereby adjusting the temperature of the experimental electric furnace, so that the temperature of the experimental electric furnace meets the specified requirements, the experimental electric furnace belongs to high-sensitivity equipment, the temperature error is small, generally about 1 degree Celsius, so it is an important test tool in the laboratory.

(3) Adjust the temperature of the experimental chamber furnace, in industry, by connecting the circuit to several cycles within the set cycle range, and then disconnecting several cycles, changing the proportion of the thyristor on and off time in the set cycle, to adjust the AC average voltage at both ends of the load, that is, the load power, which is commonly known as dynamometer or frequency controller; The dynamometer triggers thyristor to turn on when the supply voltage crosses zero, so the load gets a complete sine wave, and only the voltage cycle that is turned on in the set period Tc is adjusted. If the wavenumber of the conduction period in the period Tc is n, and the period of each cycle is T, the output power of the dynamometer is P=n× T× Pn/Tc, and Pn is the output power of the device when the voltage in the set period Tc is all passed.

The following methods are used to improve temperature uniformity for different experimental chamber furnaces:

1. The door panel of the experimental chamber furnace is tilted by 5°-10° to strengthen the sealing and reduce heat dissipation at the furnace door;

2. The channel steel slotted and roller structure is adopted, and the furnace door is pressed in place by itself;

3. Large electric furnace, ** is a simple protective atmosphere furnace using manual pressing by hand wheel;

4. Increase the resistance wire to the experimental chamber furnace door to reduce the temperature difference at the furnace door. In addition, it is possible to change the traditional method of evenly distributing heating elements, etc.;

5. Set the fan in the furnace as much as possible and achieve forced convection. Forced convection for common heat treatments is achieved by fans mounted on the roof or wall of a laboratory chamber furnace. The disadvantage of this method is that the workpiece stacked in the furnace (whether scattered or multi-layered) is close to the furnace door or the back wall of the furnace and other parts with large heat dissipation, and the power change is increased by reducing the pitch of the resistance wire spiral coil to increase the furnace gas circulation flow limit, so that most of the high-temperature circulation furnace gas flows away from the periphery of the workpiece, resulting in a temperature difference between inside and outside the workpiece stacking area. In order to narrow this temperature difference, it has to be heated slowly.