Circulation apparatus and method of controlling circulation apparatus

A circulation apparatus that supplies and collects a liquid to and from an external path, the circulation apparatus comprising:

• a storage tank in which the liquid is an object to be stored;
• a first pipe including a first inflow end into which the liquid flows from the storage tank, the first pipe being used for supplying the liquid;
• a heater in which the liquid is an object is to be heated, the heater being disposed in the first pipe;
• a pump in which the liquid is an object is to be expelled, the pump being disposed in the first pipe and including an inlet connected to the first inflow end and an outlet connected to the heater;
• a first valve connected in the first pipe to the outlet through the heater, the first valve being openable and closeable;
• a second pipe including a second inflow end connected to the first pipe between the heater and the first valve, and a second outflow end from which the liquid flows into the storage tank, the second pipe having a pressure loss value being variable;
• a third pipe including a third outflow end from which the liquid flows into the storage tank, the third pipe being used for collecting the liquid;
• and
• a controller controlling opening and closing of the first valve, and controlling the pressure loss value,
• wherein while the heater heats the liquid:
• the controller closes the first valve during a first period;
• the controller opens the first valve, and increases the pressure loss value during a second period after end of the first period;
• and
• the controller opens the first valve, and reduces the pressure loss value during a third period after end of the second period.