Refrigeration cycle apparatus

1. A refrigeration cycle apparatus, comprising: a water tank; a heat source wound around an outer peripheral portion of the water tank and configured to heat water stored in the water tank; a refrigeration cycle including: a compressor, a first heat exchanger, a first expansion valve provided downstream of the first heat exchanger in a refrigerant flow direction, the downstream being in an operation in which the first heat exchanger serves as a condenser, and a second heat exchanger wound around the outer peripheral portion of the water tank and configured to exchange heat with the water stored in the water tank; and a controller configured to execute an operation mode circulating refrigerant through, in order, a discharge outlet of the compressor, the first heat exchanger, the first expansion valve, the second heat exchanger, and a suction inlet of the compressor, and operate the heat source to evaporate the refrigerant flowing through the second heat exchanger by heat generated by the heat source, wherein the heat source is an electric heater or a gas heater.

2. The refrigeration cycle apparatus of claim 1 , wherein the refrigeration cycle further includes:

a third heat exchanger;

a first flow switching valve configured to switch a flow passage of refrigerant between:

a first passage, by which the third heat exchanger and the discharge outlet of the compressor communicate with each other and by which the second heat exchanger and the suction inlet of the compressor communicate with each other, and

a second passage, by which a refrigerant flow path is formed between the third heat exchanger and the suction inlet of the compressor and by which a refrigerant flow path is formed between the second heat exchanger and the discharge outlet of the compressor;

a first pipe connected to the first heat exchanger, in a middle of which the first expansion valve is provided;

a second pipe connected to the second heat exchanger;

a second expansion valve provided to the second pipe;

a third pipe having a first end portion connected to the first pipe and the second pipe and a second end portion connected to the third heat exchanger; and

a valve provided to the third pipe.

3. The refrigeration cycle apparatus of claim 2 , further comprising: a temperature sensor configured to detect a temperature in an installation environment of the third heat exchanger,

wherein the controller is configured to control the first flow switching valve, the first expansion valve, the second expansion valve, and the valve, and

when an operation time period of the compressor exceeds a preset time period under a state in which a detection value of the temperature sensor is equal to or less than a preset temperature, the controller executes the operation mode of the refrigeration cycle.

4. The refrigeration cycle apparatus of claim 2 , further comprising:

a temperature sensor configured to detect a temperature in an installation environment of the third heat exchanger, wherein

the controller is configured to control the first flow switching valve, the first expansion valve, the second expansion valve, and

the valve, and when a detection value of the temperature sensor is equal to or less than a preset temperature, the controller executes the operation mode of the refrigeration cycle.

5. The refrigeration cycle apparatus of claim 1 , further comprising a second flow switching valve configured to switch between forming a third passage, by which the first heat exchanger and the discharge outlet of the compressor communicate with each other, and a fourth passage, by which the first heat exchanger and the suction inlet of the compressor communicate with each other.