Based on the construction conditions of 2×1 000 MW coal-fired unit

this paper makes technical research and analysis on the wide-load coal-saving effect

cost

investment payback period and system complexity of the three flue gas waste heat utilization schemes through supporting the construction of low-temperature economizer scheme

hot medium water scheme and air preheater bypass scheme.It is considered that the wide load coal saving effect of air preheater bypass scheme is the best

but the initial investment is the highest and the system is the most complicated.The wide load coal saving effect of the low-saving economizer scheme is the worst

but the initial investment is low and the system is simple.When the standard coal price is high

the investment payback period of air preheater bypass scheme and heat medium water scheme is short.