Northern iron and steel enterprises are often equipped with gas or coal-fired boilers for heating, and due to the limited heating period, the equipment has fewer utilisation hours throughout the year, and the initial and environmental investment in the equipment is higher. The introduction of molten salt energy storage, the use of low-temperature applicable interval of molten salt and low-temperature flue gas heat exchange and storage, the use of valley heating to maintain the stability of the molten salt system heating, can solve the low energy efficiency of low-level waste heat power generation in the whole plant, saturated steam power generation operation is unsafe, reduce the use of coal-fired, gas-fired boilers, and replace the gas to high-efficiency gas generator sets to generate power, improve the energy efficiency of waste heat and waste energy use to reduce emissions, increase the whole factory Power generation.