Closed crankcase ventilation system and engine

The utility model provides a closed crankcase ventilation system and an engine. The closed crankcase ventilation system comprises an oil-gas separator, a blow-by gas collecting pipe, a controller, a first detector, a heater and a second detector. The oil-gas separator is used for being communicated with a crankcase of an engine, one end of the blow-by gas collecting pipe is communicated with the oil-gas separator, the other end of the blow-by gas collecting pipe is communicated with a supercharger of the engine, the heater, the first detector and the second detector are all arranged on the blow-by gas collecting pipe, and the heater is located between the first detector and the second detector. The first detector is located on the side, facing the crankcase, of the heater. And the heater, the first detector and the second detector are electrically connected with the controller. The closed crankcase ventilation system provided by the utility model is higher in reliability. 本实用新型提供一种闭式曲轴箱通风系统及发动机。闭式曲轴箱通风系统包括油气分