Reservoir tank

A reservoir tank comprising:

• a coolant introduction pipe configured to allow coolant to be introduced from an outside of the reservoir tank therethrough such that the coolant is guided to a lower part of the reservoir tank, the coolant introduction pipe comprising a first pipe body having one end protruding outwardly of the reservoir tank and the other end extending into the reservoir tank and a second pipe body extending downward from the first pipe body;
• and
• a coolant discharge pipe provided at the lower part of the reservoir tank, the coolant discharge pipe being configured to guide the coolant introduced into the reservoir tank through the coolant introduction pipe such that the coolant is discharged from the reservoir tank, the coolant discharge pipe comprising a longitudinal flow channel extending in a longitudinal direction and a transverse flow channel extending in a transverse direction, the transverse flow channel being joined to the longitudinal flow channel, wherein
• the longitudinal flow channel is disposed at a lower part of the second pipe body, some of the coolant flowing downward through the second pipe body is introduced into the longitudinal flow channel, passes through the transverse flow channel, and is discharged from the reservoir tank through an outlet of the transverse flow channel, and a remainder of the coolant flowing downward through the second pipe body exits from the longitudinal flow channel, flows into the reservoir tank, is introduced into an inlet of the transverse flow channel, and is discharged from the reservoir tank through the outlet.