Cold water unit and control method thereof

The invention relates to a cold water unit and a control method thereof. The cold water unit comprises a compressor (1), a condenser (2), a throttling component (3), an evaporator (4), a storage box (5), a heating pipe (6) and an electric heating device (7), wherein the condenser (2) is connected to the compressor (1), the throttling component (3) is connected to the condenser (2), the evaporator(4) is connected between the throttling component (3) and the compressor (1), the storage box (5) stores a cooling liquid internally, the cooling liquid exchanges heat with a heat exchanging medium inthe condenser (2) to cool the heat exchanging medium, the heating pipe (6) is arranged at the bottom of the storage box (5), a heating medium circulates in the heating pipe (6) and is used for heating the cooling liquid, and an electric heating device (7) is arranged at the bottom of the storage box body (5) and is configured to heat the cooling liquid by electric energy heating. The cold water unit can prevent the coolin