Heat pump system using shell and tube heat exchangers and three-way valves

A heat pump system, comprising:

• a compressor that compresses a refrigerant;
• a condenser that condenses the refrigerant compressed in the compressor, wherein the condenser includes a first heat exchanger of a first shell and tube heat exchanger or a second shell and tube heat exchanger;
• an expansion device that decompresses the refrigerant condensed in the condenser;
• and
• an evaporator that evaporates the refrigerant decompressed in the expansion device, wherein the evaporator includes a second heat exchanger of the first shell and tube heat exchanger or the second shell and tube heat exchanger;
• a plurality of flow switching devices that switches a flow direction of the refrigerant flowing into the first shell and tube heat exchanger or the second shell and tube heat exchanger, wherein the plurality of flow switching devices includes a first flow switching device provided at an outlet-side of the compressor, a second flow switching device that guides the refrigerant decompressed in the expansion device into the evaporator, a third flow switching device that guides the refrigerant heat-exchanged in the condenser into the expansion device, and a fourth flow switching device that guides the refrigerant heat-exchanged in the evaporator into the compressor;
• a first connection tube that extends from the first flow switching device to the first shell and tube heat exchanger;
• a second connection tube that extends from the first flow switching device to the second shell and tube heat exchanger;
• a third connection tube that extends from a point on the first connection tube to the second flow switching device;
• and
• a fourth connection tube that extends from a point on die second connection tube to the second flow switching device, wherein each of the first shell and tube heat exchanger and the second shell and tube heat exchanger is switchable into the condenser or the evaporator according to a cooling or heating operation, and wherein each of the first and second heat exchangers includes:
• a shell into which the refrigerant is introduced;
• a plurality of tubes provided within the shell and into which a fluid heat-exchanged with the refrigerant flows;
• two inlet/outlets provided on a first side of the shell to guide the introduction or discharge of the refrigerant;
• and
• one inlet/outlet provided on a second side of the shell to guide the introduction or discharge of the refrigerant.