Hot water supply tank

A hot water supply tank comprising:

• a storage part in which a fluid is stored;
• an internal water outlet pipe through which the fluid flows from the storage part to a heat pump;
• an internal water inlet pipe through which the fluid flows from the heat pump to the storage part;
• and
• an internal pipe disposed in the storage part,
• wherein the internal pipe comprises:
• a connection pipe connected to the internal water inlet pipe and having at least a portion being flexible;
• and
• a discharge pipe having one end connected to the connection pipe and being elongated and non-flexible,
• wherein at least one pipe through-hole formed through the discharge pipe is defined at another end of the discharge pipe,
• wherein a maximum horizontal length of the internal pipe is equal to a sum of a maximum length of the connection pipe and a fixed length of the discharge pipe, and is less than a diameter of the storage part,
• wherein the maximum length of the connection pipe is less than the fixed length of the discharge pipe, and
• wherein a specific gravity of the discharge pipe corresponds to a specific gravity of the fluid at a predetermined temperature.