The invention relates to an energy saving device for using
waste heat of a power
plant for urban centralized
heat supply and an energy saving method of the energy saving device. According to the structure of the energy saving device, a steam exhaust opening of a power
plant turbine is cooled through a power
plant cooling
system, a
heat supply main
heat exchanger is arranged on a
heat supply primary network, and a heat source inlet of the heat supply main
heat exchanger is connected with a steam extraction opening of the power plant
turbine; the steam exhaust opening of the power plant
turbine is connected with an inlet of a condenser; a hot water heat exchange channel is formed in the condenser, a primary network water return pipeline is connected with an inlet of the hot water heat exchange channel, and an outlet of the hot water heat exchange channel is connected with an inlet of the heat supply main
heat exchanger through a heat supply main
circulating pump; uncondensed waste steam of the condenser is cooled through the power plant cooling
system. The energy saving device enables a steam condensing
system of the power plant and an urban concentrated heat supply system to be combined in a high degree, a steam condensing device of the power plant is transformed, system
waste heat which is originally exhausted to the
atmosphere is recycled as much as possible, in this way, the comprehensive heat efficiency of the power plant is improved, power generation
energy consumption is lowered, and part of the heat source problem of urban heat supply is solved.