Electric heating steam overheating system

Abstract

The invention discloses an electric heating steam overheating system. The electric heating steam overheating system comprises a heat-conduction oil electric heating device (10), an oil-steam heat exchange device (20), an oil-gas separator (30) and an expansion tank (40) which are connected through a pipeline. The heat-conduction oil electric heating device (10) can heat heat-conduction oil, and the heat-conduction oil in the heat-conduction oil electric heating device (10) can enter the oil-steam heat exchange device (20). The oil-steam heat exchange device (20) is externally connected with asteam input pipeline (21) and a steam output pipeline (22), and heat-conduction oil in the oil-steam heat exchange device (20) can heat steam in the oil-steam heat exchange device (20). According to the electric heating steam superheating system, electric energy serves as a heat source, the heat-conduction oil serves as an intermediate heat exchange medium, converter vaporization waste heat saturated steam is heated into micro superheated steam to be used by a steam pump of an RH vacuum refining furnace of a steel mill, and the steam system for intermittent production of the refining furnace is met.

Description

technical field [0001] The invention relates to an electric heating steam superheating system. Background technique [0002] Iron and steel enterprises often adopt steam jet pump vacuum refining method to smelt clean steel. Steam jet pump needs superheated steam as power source, and its production feature is a periodic intermittent operation mode. [0003] At present, the main sources of superheated steam used by steam jet pumps are as follows: First, the superheated steam is produced by fast boilers using fuel combustion as the heat source. Second, the superheated steam is produced by using the medium-temperature, medium-pressure and above parameter steam of the power plant to reduce temperature and pressure. Third, use the steelmaking converter and electric furnace production process to produce saturated steam and heat it to produce superheated steam. A variety of technologies and products are available for superheating the saturated steam produced by converters and elec...

AI Technical Summary

Problems solved by technology

When the refining furnace is stopped for a moment, the electric heating element cannot be cooled without steam circulation, and it is in a dry burning state. For the electric heating element in the resistance heating mode, it is easy to burn out if it is operated for a long time

Saturated steam will more or less carry liquid water. Liquid water has a certain hardness. Liquid water evaporates on the surface of the electric heater, and the hardness remains on the surface of the electric heater. Long-term use of the electric heater surface is seriously scaled, which affects the heat transfer efficiency.

For the resistance heating mode, the life of the electric heater is short and the replacement rate is high. For the electromagnetic induction mode, the power consumption rate increases and the life of the electric heater is shortened.

[0007] The micro-overheating and variable pressure regenerator system using itself as the heat source does not consider the fluctuation of the high-pressure steam pressure and temperature of the regenerator, and does not consider the working conditions of the exothermic end of the regenerator, so it cannot accurately control the superheat of the outlet steam, and even Does not meet the needs of the specified user

[0008] Using molten salt as an intermediate medium to indirectly heat saturated steam, using a submerged heat exchanger, the heat exchange intensity is low, and it is difficult to achieve precise temperature adjustment of superheated steam

In addition, the composition of the molten salt is relatively complex, and the molten salt may contain some impurity salts that will form thermal scaling on the surface of the heating tube, such as calcium carbonate, which will cause the complexity of the system or affect the continuous service life of the system

[0009] The method of indirectly heating saturated steam with heat transfer oil as an intermediate medium, and the method of setting an electric heater in a large-volume hot oil tank, the flow rate of the heat transfer oil in the hot oil tank cannot guarantee the flow rate allowed by the heat transfer of the heat transfer oil, and the heat transfer on the surface of the electric heater Low strength can easily cause over-temperature cracking of the oil film on the surface of the electric heater

At the same time, the hot oil tank operates under normal pressure, and the high-temperature heat transfer oil is easy to oxidize and deteriorate

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