The invention discloses a
system and method for heating feed water through reheat steam to achieve deep peak regulation. According to the
system and method, a steam-steam
heat exchanger serves as a full-load-section operation
system, steam behind a rear screen is used for heating cold reheat steam, the reheat steam is used for heating the feed water, and low-pressure steam heated through the rear screen is extracted for heating a primary air pulverized
coal pipeline. When the system runs, reheated steam is pumped to heat feed water through the steam-water
heat exchanger, the temperature of the feed water and the wall temperature of the
water cooling wall are increased, and the
combustion condition of the boiler is improved; after the cooled steam absorbs heat in the steam-steam heater, part of the cooled steam is pumped out to heat primary air pulverized
coal airflow, the initial temperature of the pulverized
coal airflow is increased, and the ignition and stable
combustion performance of the boiler is improved; heat of the
superheater is guided out through the steam-steam-water
heat exchanger, part of heat of
superheated steam and reheated steam is used for increasing the feed
water temperature and the primary air pulverized coal
airflow temperature, and the effects that the low-load ignition stability is improved, the load point for converting the boiler into the wet state is increased, the deep adjustment load of the boiler is reduced, and the
unit operation flexibility is improved are achieved.