Abstract: A heat pump system comprises: a compressor having a compressor inlet and a compressor outlet; a change-over valve configured to selectively connect the compressor inlet and the compressor outlet to a first flow path and a second flow path; a heat-source-side heat exchanger on the first flow path; a user-side heat exchanger on the second flow path; a first branch and a second branch between the first flow path and the second flow path, the first branch having a three-way valve, and the second branch having a two throttling devices, wherein the three-way valve has two ports for communicating with the first flow path and a third port for communicating with the second flow path; and a third branch connected between the first throttling device and the second throttling device and the second port of the three-way valve, where an economizer is provided on the third branch.

Abstract: A heat pump system and a control method thereof. The heat pump system includes: a major heat exchange loop (100), including at least one compressor (110), a flow-path switching valve (120), a condenser (130), a first throttling element (140), an economizer (150), and an evaporator (160) that are connected sequentially to form a loop; and an air supply branch (200), which is connected from a flow path between the first throttling element and the economizer to an air supply inlet of the compressor, the air supply branch being provided with a switch valve (231) for preventing a gas-phase refrigerant from flowing back; where a pressure balance branch (300) is further included, which is connected from the air supply branch at the upstream of the switch valve to a low-pressure gas-phase refrigerant side of the major heat exchange loop.

Abstract: A heat pump system comprises a compressor, a first heat exchanger, a second heat exchanger, a mode switching valve, a throttling element and a reservoir, wherein the throttling element is arranged on a flow path between the first heat exchanger and the second heat exchanger; and which further comprises a mode switching flow path in which a first flow path and a second flow path are arranged, the reservoir is arranged on the second flow path and each flow path is controllably opened or closed to realize different functional modes.

Abstract: A defrosting control method comprises: initializing a first default parameter TMn and a second default parameter TNn in a preset defrosting interval indicatrix X when a heat pump system runs, wherein the preset defrosting interval indicatrix X=T1/TMn+T2/TNn; executing the defrosting cycle when the preset defrosting interval indicatrix X is greater than or equal to a preset constant value, and terminating the defrosting cycle after a defrosting cycle exit condition is met; obtaining an actual time spent on the defrosting cycle; comparing the actual time spent on the defrosting cycle with an expected defrosting time, and adjusting the first default parameter and the second default parameter when the actual defrosting time deviates from the expected defrosting time.

Abstract: A heat pump system and a control method thereof. The heat pump system includes: a major heat exchange loop (100), including at least one compressor (110), a flow-path switching valve (120), a condenser (130), a first throttling element (140), an economizer (150), and an evaporator (160) that are connected sequentially to form a loop; and an air supply branch (200), which is connected from a flow path between the first throttling element and the economizer to an air supply inlet of the compressor, the air supply branch being provided with a switch valve (231) for preventing a gas-phase refrigerant from flowing back; where a pressure balance branch (300) is further included, which is connected from the air supply branch at the upstream of the switch valve to a low-pressure gas-phase refrigerant side of the major heat exchange loop.

Abstract: A heat pump system, a controlling method thereof, and a heat pump unit using the heat pump system. The heat pump system includes a compressor, a first heat exchanger, a second heat exchanger, a heat-recovery-type heat exchanger, a multi-way valve, a throttling element, and a mode-switching flow path, which has both air conditioning and water heating functions. By switching the multi-way valve and powering on/off electromagnetic valves in the heat pump system, the controlling method controls the heat pump system to implement multiple functional modes. Furthermore, the heat pump unit using the heat pump system provides multiple functions simply by laying a small amount of parts and elements and pipelines outdoors, thereby greatly reducing the engineering cost and cost of parts, and ensuring a much higher water heating efficiency.

Abstract: A heat pump system comprises a compressor, a first heat exchanger, a second heat exchanger, a mode switching valve, a throttling element and a reservoir, wherein the throttling element is arranged on a flow path between the first heat exchanger and the second heat exchanger; and which further comprises a mode switching flow path in which a first flow path and a second flow path are arranged, the reservoir is arranged on the second flow path and each flow path is controllably opened or closed to realize different functional modes.

Abstract: The present invention discloses a heat pump system, a controlling method thereof, and a heat pump unit using the heat pump system. The heat pump system includes a compressor, a first heat exchanger, a second heat exchanger, a heat-recovery-type heat exchanger, a multi-way valve, throttling elements, and a mode-switching flow path, which has both air conditioning and water heating functions. By switching the multi-way valve and powering on/off electromagnetic valves in the heat pump system, the controlling method controls the heat pump system to implement multiple functional modes. Furthermore, the heat pump unit using the heat pump system provides multiple functions simply by laying a small amount of parts and elements and pipelines outdoors, thereby greatly reducing the engineering cost and cost of parts, and ensuring a much higher water heating efficiency.