Air conditioner and control method thereof

A control method of an air conditioner, wherein the air conditioner includes:

• an outdoor unit, the outdoor unit including a compressor;
• at least one indoor unit;
• a refrigerant circulation loop, the outdoor unit being connected to the at least one indoor unit through the refrigerant circulation loop;
• and
• a controller coupled to the outdoor unit, the indoor unit, and the refrigerant circulation loop;
• the method comprises:
• determining whether the air conditioner is operating in one of a cooling mode and a heating mode according to an outdoor ambient temperature, a return air temperature of the indoor unit, and an operating state of the indoor unit;
• and
• the method further comprises:
• performing a first refrigerant amount determining mode if it is determined that the air conditioner is operating in the cooling mode, and the air conditioner is operating stably in the cooling mode, the performing the first refrigerant amount determining mode including:
• obtaining a first target supercooling degree in a first standard condition;
• calculating a first target refrigerant amount according to the first target supercooling degree;
• wherein the first target refrigerant amount is greater than or equal to 0;
• converting a supercooling degree in a current condition into a supercooling degree in the first standard condition according to the supercooling degree in the current condition and a first supercooling degree correction value;
• calculating a refrigerant amount corresponding to the supercooling degree in the first standard condition according to the supercooling degree in the first standard condition;
• wherein the refrigerant amount corresponding to the supercooling degree in the first standard condition is greater than or equal to 0;
• calculating a first refrigerant amount difference according to the refrigerant amount corresponding to the supercooling degree in the first standard condition, the first target refrigerant amount, an outdoor unit internal volume in the current condition, and an outdoor unit internal volume in the first standard condition;
• and
• determining a refrigerant amount of the air conditioner according to the first refrigerant amount difference;
• wherein after the air conditioner operates in the cooling mode for a preset duration, an exhaust temperature of the compressor is periodically collected, and that the air conditioner is operating stably in the cooling mode, includes:
• a difference between two adjacent exhaust temperatures collected being within a first preset temperature range, a first superheat degree of the indoor unit being greater than a first preset value and lasts for a first period, and a second superheat degree of the indoor unit being less than a second preset value and lasts for a second period;
• or,
• performing a second refrigerant amount determining mode if it is determined that the air conditioner is operating in the heating mode, and the air conditioner is operating stably in the heating mode, the performing the second refrigerant amount determining mode including:
• obtaining a second target supercooling degree in a second standard condition;
• calculating a second target refrigerant amount according to the second target supercooling degree;
• wherein the second target refrigerant amount is greater than or equal to 0;
• converting a supercooling degree in a current condition into a supercooling degree in the second standard condition according to the supercooling degree in the current condition and a second supercooling degree correction value;
• calculating a refrigerant amount corresponding to the supercooling degree in the second standard condition according to the supercooling degree in the second standard condition;
• wherein the refrigerant amount corresponding to the supercooling degree in the second standard condition is greater than or equal to 0;
• calculating a second refrigerant amount difference according to the refrigerant amount corresponding to the supercooling degree in the second standard condition, the second target refrigerant amount, an indoor unit internal volume in the current condition, and an indoor unit internal volume in the second standard condition;
• and
• determining the refrigerant amount of the air conditioner according to the second refrigerant amount difference;
• wherein after the air conditioner operates in the heating mode for a preset duration, an exhaust temperature of the compressor is periodically collected, and that the air conditioner is operating stably in the heating mode, includes:
• a difference between two adjacent exhaust temperatures collected being within a second preset temperature range.