Environmental factors include the media in the system, thermal coupling, ambient temperature, heat dissipation conditions, and load conditions. This refers to the heat consumption factors, which have a greater influence on the working state of the heater.
The volt-ampere characteristics of the heater in different media are different due to the dissipation conditions of the medium. Under the same operating voltage, the steady-state operating power P water> P oil> P empty, and the heater in their respective media can be in Huan temperature heating in a wide voltage range. The ambient temperature also has a certain influence on the working state of the PTC heater, however, when the ambient temperature is not much different,
Or when the applied voltage is sufficient to cause the heater to perform automatic thermal compensation, the heater can still maintain a constant temperature and heat. The change in thermal load also has a certain impact on the constant temperature characteristics of the PTC heater. The drift of the constant temperature point is mainly caused by the increase
The compensation capacity and load of the heater are determined. To be sure, the change in thermal load state will cause the system thermal balance to rebuild.
The temperature characteristics of the welding tip of two types of PTC electric irons with different compensation capabilities during welding. Since the heating and compensation capacity of PT-201 is lower than that of PT-301, the temperature fluctuation range of welding elbow is also larger. After the thermal load is determined, the working system re-balances, and the heater can be considered to work at a constant temperature.
In addition, attention must be paid to the design of the heat sink as part of the heater. Most PTC heaters consist of PTC elements and heat sinks sandwiched with them. For a PTC component with limited heat generation capacity, a well-designed heat dissipation plate, under good thermal coupling conditions, is an effective way to fully explore the heat generation capacity of the component and obtain the desired thermal effect. PTC can also be used as a current-limiting element or temperature-sensing element to make a certain heater generate heat at a constant temperature in the system. This is also extremely widely used in household appliances.
