The high and low temperature integrated machine achieves dynamic temperature control over a wide temperature range and high precision by integrating refrigeration and heating systems, combined with circulating media and intelligent control algorithms. The core collaborative control principle is as follows:
1. Refrigeration system: Compression refrigeration cycle achieves low-temperature control
The refrigeration system is centered around a compressor, which drives the refrigerant (such as R404A) to complete the cycle. The compressor compresses low-temperature and low-pressure gaseous refrigerant into high-temperature and high-pressure gas, which enters the condenser to release heat and condense into liquid state; After being throttled and depressurized by the expansion valve, the liquid refrigerant enters the evaporator to absorb the heat of the circulating medium (such as heat transfer oil), evaporates into a gaseous state, and returns to the compressor, forming a closed-loop refrigeration cycle. By adjusting the compressor start stop frequency and refrigerant flow rate, the system can accurately control the cooling rate and achieve a low-temperature environment from -80 ℃ to room temperature.
2. Heating system: The electric heating element directly heats up
The heating system uses electric heating tubes (such as stainless steel material) to directly apply electricity to the circulating medium for heating, converting electrical energy into thermal energy. The heating power is designed according to the process requirements (such as 10kW, 50kW) to ensure reaching the target high temperature (such as 200 ℃) within the set time. The heated medium is transported to the target device through a circulation pump, and its temperature is increased using the principle of thermal conduction.
3. Collaborative control: PID algorithm dynamically balances cold and hot outputs
Heating mode: prioritize starting the heating system to quickly increase the temperature; The PID controller adjusts the heating power in real-time based on temperature deviation to prevent overshoot.
Cooling mode: Priority is given to starting the refrigeration system, while the heating system intervenes with "compensatory temperature control" to avoid equipment stress damage caused by sudden temperature drops.
Constant temperature mode: When the temperature approaches the set value, the system automatically reduces the heating/cooling power and fine tunes the output through PID algorithm to maintain temperature stability (with an accuracy of ± 0.1 ℃).
Quick switching: The system can switch between high temperature (such as 200 ℃) and low temperature (such as -40 ℃) in seconds through components such as cold and hot switching valves, meeting the sudden change requirements of polymerization reactions and other processes.
4. Circulating system: Closed pipeline improves efficiency and safety
Adopting a fully enclosed pipeline design to reduce the consumption of thermal conductive media and the risk of oxidation; Built in plate heat exchanger and magnetic driven pump to improve thermal energy utilization and prevent leakage. The expansion container isolates the medium from contact with air, avoiding the generation of oil mist at high temperatures or the condensation of water vapor at low temperatures, thereby extending the service life of the medium.
5. Security protection: Multi level protection ensures stable operation
The system is equipped with Pt100 temperature sensors, pressure switches, liquid level sensors, etc., to monitor real-time parameters such as temperature, pressure, and liquid level. When abnormal conditions such as overheating, overvoltage, and leakage occur, the equipment will automatically shut down and sound an alarm to ensure the safety of personnel and equipment.