Heat pump system and control method thereof

Abstract

A heat pump system according to an aspect of the disclosure may comprise: a compressor configured to compress a refrigerant; a water heat exchanger configured to exchange heat between the compressed refrigerant and introduced water; an expansion valve configured to expand the refrigerant condensed in the water heat exchanger; an outdoor heat exchanger configured to exchange heat between the refrigerant expanded by the expansion valve and outdoor air; a high-tension pressure sensor configured to detect the temperature of the refrigerant to be condensed in the water heat exchanger; a discharged water temperature sensor configured to detect the temperature of water on which heat exchange has been performed in the water heat exchanger; and a control unit including a controller comprising circuitry configured to: determine a target condensation temperature of the refrigerant based on a detection result of the discharged water temperature sensor, compare the target condensation temperature with the current condensation temperature detected by the high-tension pressure sensor, and control the degree of opening of the expansion valve based on the comparison result.