■Molten salt electric heater：
Molten salt electric heater is an electrical heating device used for heating, insulating, and heating flowing liquid and gaseous media. The molten salt electric heater utilizes a special tubular electric heating element combined with a flange bundle to form a heating whole with a pressure vessel, using binary or ternary molten salt as the heating medium. Generally, this heating method forms a whole with the molten salt tank. After the nitrate at room temperature is poured into the molten salt tank, a small amount of electric heating elements inside the molten salt tank are used to preheat it and turn it into a liquid state. Then, the molten salt is extracted by a molten salt pump to flow inside the heater, further heating the molten salt. The purpose of heating is basically completed at the outlet of the molten salt heater, and it forms a circulating whole with the user's heating equipment, Continuously heat it to meet the requirements of the process.
■Application range of molten salt electric heater:
Molten salt electric heaters are widely used in high-temperature heating production processes such as energy storage, heat storage, thermal power peak shaving, fertilizers, melamine, alumina, etc.
■Overview of the control system for molten salt electric heaters:
1、There are conventional electrical protections, such as flow and short circuit protection.。
2、There is an overtemperature alarm system independent of temperature control. When the internal temperature of the electric heater exceeds the set value, it will shut down the electric heater without automatic reset and output a contact signal.
3、There is an independent low liquid level alarm that automatically shuts down the electric heater and outputs a signal when the liquid level falls below the required value.
4、Provide several interlocking interfaces for interlocking with other devices such as pumps, flow (pressure) switches, etc., to ensure a certain flow of medium during heating of the heater and ensure the safety of the system.
5、Control can provide signals to the DCS system, such as heating system running, stopping, over temperature alarm, liquid level signal (low liquid level alarm), interlock status, temperature signal (4-20mA), etc. Except for temperature signal, they are all passive contacts; It can accept the start and stop operation commands issued by DCS, and the required contact capacity is also 220V 1A.
6、Equipped with PID temperature regulation function, the heating system can set the temperature rise curve of the medium through a program, and can control the pump according to process requirements when the flow rate is insufficient or heating is stopped. This control system adopts multi-level control technology, which divides the heaters into several groups, one of which is a large group that can be stepless adjusted. Based on the outlet temperature, after calculation, The control system automatically controls the on-off of each group of heaters and the output power of another group of heaters, achieving stepless power regulation. In this way, the goal of improving temperature control accuracy can be effectively achieved.
