A refrigeration cycle of a refrigerator comprising a first refrigeration cycle in which a first refrigerant flows along a first refrigerant tube, the first refrigerant being configured to cool one of a refrigerating compartment or a freezing compartment and a second refrigeration cycle in which a second refrigerant flows along a second refrigerant tube, the second refrigerant being configured to cool the other of the refrigerating compartment or the freezing compartment, the refrigeration cycle comprising:
- a first compressor configured to compress the first refrigerant into a high-temperature high-pressure gaseous refrigerant, and a second compressor configured to compress the second refrigerant into a high-temperature high-pressure gaseous refrigerant;
- a combined condenser condensing each of the first refrigerant passing through the compressor and the second refrigerant passing through the second compressor into a high-temperature high-pressure liquid refrigerant;
- a first expansion valve configured to change a phase of the first refrigerant passing through the combined condenser into a low-temperature low-pressure two-phase refrigerant, and a second expansion valve configured to change a phase of the second refrigerant passing through the combined condenser into a low-temperature low-pressure two-phase refrigerant;
- and
- a first evaporator configured to change the first refrigerant passing through the first expansion valve into a low-temperature low-pressure gaseous refrigerant, and a second evaporator configured to change the second refrigerant passing through the second expansion valve into a low-temperature low-pressure gaseous refrigerant,
- wherein the combined condenser comprises:
- a first condensation tube that is a portion of the first refrigerant tube that connects the first compressor to the first expansion valve;
- a second condensation tube that is a portion of the second refrigerant tube that connects the second compressor to the second expansion valve;
- and
- a plurality of heat-exchange fins contacting one of or both surfaces of the first and second condensation tubes,
- wherein the first and second condensation tubes share at least a portion of the heat- exchange fins,
- wherein each of the first and second condensation tubes has a shape of a flat tube with a predetermined width and length,
- wherein the first and second condensation tubes are vertically spaced apart from each other and are disposed in parallel to each other,
- wherein the first condensation tube comprises a plurality of first bent portions that are bent or rounded a first number of times, and a plurality of first flat portions, each first flat portion extending from one of the plurality of first bent portions to form a first meander line,
- wherein the second condensation tube comprises a plurality of second bent portions that are bent or rounded a second number of times, and a plurality of second flat portions, each second flat portion extending from one of the plurality of second bent portions to form a second meander line,
- wherein the plurality of heat-exchange fins are inserted in-between the first and second condensation tubes that are vertically adjacent thereto,
- wherein each heat-exchange fin is bent several times in a wave form to define upper cusps and lower cusps at bent portions of the heat-exchange fin,
- wherein the upper cusps and lower cusps of the plurality of heat-exchange fins contact one of or both surfaces of the first and second condensation tubes, and wherein, the plurality of heat-exchange fins include, in a stand-alone operation mode of the first refrigeration cycle or the second refrigeration cycle, first parts that performs heat-exchange operation and second parts that do not participate in the heat-exchange operation, and
- wherein a number of the plurality of first flat portions is different from a number of the plurality of second flat portions.