Passive residual heat exhausting system of pressurized water reactor nuclear power plant

The invention provides a passive residual heat exhausting system of a pressurized water reactor nuclear power plant. The passive residual heat exhausting system comprises a passive residual heat removal system and a passive emergency water tank cooling system, wherein the passive residual heat removal system comprises a steam pipe, a passive residual heat exhausting heat exchanger and a condensed water pipe; the passive residual heat exhausting heat exchanger is positioned at the lower part of an emergency cooling water tank of the passive residual heat removal system; the passive emergency water tank cooling system comprises the emergency cooling water tank, a cooling coiled pipe, an ascending pipe, an air cooling heat exchanger and a descending pipe; the cooling coiled pipe is located at the upper part of the emergency cooling water tank. When residual heat removal needs to be carried out under an accident condition or normal shutdown, decay heat of a reactor core is removed by condensing steam at a secondary side so that the safety of a reactor is guaranteed and the possibility of releasing radioactive substances to the environment is reduced. The emergency cooling water tank is used as middle buffering equipment so as to meet the requirements of rapid cooling at the initial stage of an accident and long-time cooling at the later period of the accident.