Intake air cooling system in engine

An intake air cooling system in an engine for cooling intake air being supplied to a cylinder of the engine, comprising:

• an intake manifold provided for guiding the intake air to the cylinder;
• a connection passage in communication with the intake manifold for introducing the intake air to the intake manifold;
• an intake passage provided for receiving an outdoor air and in communication with the connection passage;
• a compressor provided for compressing the outdoor air passed through the intake passage and forwarding the outdoor air compressed thus to the connection passage as the intake air;
• an intercooler arranged on the connection passage for cooling the outdoor air compressed by the compressor with cooling water;
• a low temperature radiator for dispersing heat remaining in the cooling water passed through the intercooler to air;
• a cooling water passage arranged to circulate the cooling water while passing through the low temperature radiator, the compressor, and the intercooler in succession;
• and
• a water pump for pumping the cooling water to circulate along the cooling water passage.