This paper presents precise temperature control of oil outlet in an oil cooler with hot-gas bypass control as an industrial refrigerator. The control system was designed for obtaining precise temperature control performance even though abrupt disturba...
This paper presents precise temperature control of oil outlet in an oil cooler with hot-gas bypass control as an industrial refrigerator. The control system was designed for obtaining precise temperature control performance even though abrupt disturbances based on flow rate control of hot-gas bypass. PID controller was adopted in feedback control system. We showed that the gain of PID could be easily determined by using gain-tuning methods without any numerical model. Through some experiments, excellent control performances such as overshoot within 1.7%, steady state temperature error within ±0.1℃ were established by a simple PI controller. We expect that the system can control the target temperature within error of 0.33℃ under abrupt disturbances.