Waste heat gradient utilization water heating system based on gas internal combustion engine generator set

The utility model provides a hot water system based on waste heat gradient utilization of a gas internal combustion engine generator set. The hot water system comprises a first heat exchanger 1, a second heat exchanger 2, a third heat exchanger 3, a first hot water heat storage tank 4, a second hot water heat storage tank 5, a hot water buffer tank 6, an inner circulating pump 7, an outer circulating pump 8, a first three-way valve 9, a second three-way valve 10 and a tap water replenishing pipe 11, and the temperature-regulating tap water pipeline 12 is composed of a pipeline and a common valve. Medium-temperature water, high-temperature water and flue gas waste heat or other heat source hot water of the gas internal combustion engine generator set are connected in series through the three stages of heat exchangers, the utilization problem of the medium-temperature water, the high-temperature water and the flue gas waste heat of the gas internal combustion engine is well solved, and heat is utilized in a gra