An air-conditioning apparatus includes a controller which calculates a composition ratio of a refrigerant mixture using a high-pressure-side pressure of a refrigerant discharged from a compressor, a low-pressure-side pressure of a refrigerant to be sucked into the compressor, a high-pressure-side temperature of a refrigerant at an inlet side of a second expansion device in a high/low pressure bypass pipe, and a low-pressure-side temperature of a refrigerant at an outlet side of the second expansion device in the high/low pressure bypass pipe and which determines whether to open or close a bypass-channel opening/closing device.

A valve body in each of heat medium flow switching devices has an open portion. When the length from a connection between a first passage pipe and a third passage pipe to a connection between a second passage pipe and the third passage pipe is defined as a casing passage width, a valve body passage width of the open portion in a direction substantially perpendicular to the axis of the valve body is smaller than the casing passage width.

A non-stop defrosting multi-connected hot water system and a control method. Heat is recovered by utilizing the characteristic of a phase-change heat storage module that can store heat, and then the heat is released during defrosting. In a defrosting process, modes of a hydraulic module and an indoor unit are not changed, and a four-way valve is not reversed, so as to avoid the influence of the defrosting process on an indoor ambient temperature and a water temperature of the hydraulic module, and avoid the condition where a liquid refrigerant generated in the defrosting process does not evaporate and directly flows back into a compressor which causes liquid return of the compressor, thus improving the reliability of the overall operation of the system.

One aspect provides an air conditioner, including a compressor; a condenser; an evaporator; and one or more flexible lines connecting two or more of the compressor, condenser, and the evaporator to place them into fluid communication with one another. Other aspects include a method of providing flexible lines for an air conditioner as well as kits relating thereto.

An air conditioning apparatus is provided that may include an outdoor unit including a compressor and an outdoor heat exchanger and through which a refrigerant is circulated, an indoor unit through which a fluid, such as water is circulated, and at least one heat exchange device including a heat exchanger in which the refrigerant and the fluid are heat-exchanged with each other. The at least one heat exchange device may include a high-pressure guide tube that extends from a high-pressure gas tube of the outdoor unit so as to be connected to a first side of the heat exchanger, a low-pressure guide tube that extends from a low-pressure gas tube of the outdoor unit so as to be combined with the high-pressure guide tube, a liquid guide tube that extends from a liquid tube of the outdoor unit so as to be connected to a second side of the heat exchanger, and a solenoid valve installed in the high-pressure guide tube or the low-pressure guide tube to perform an opening and closing operation so as to allow the refrigerant to flow in a first direction. The high-pressure gas tube and the low-pressure gas tube may be connected to each other by a single gas tube, and when the indoor unit performs a cooling operation or a heating operation, flow of refrigerant in the first direction may be blocked in a state in which power is applied to the solenoid valve.

A heat source controller performs a first operation when a compression element is in a stopped state and a pressure in a receiver exceeds a predetermined first pressure. The heat source controller allows an inlet of the compression element to communicate with the receiver, and drives the compression element in the first operation.

A refrigerant circuit has a liquid passage that allows a receiver to communicate with a utilization heat exchanger, and a first expansion valve provided in the liquid passage. The controller opens the first expansion valve when the compression element is in the stopped state and a pressure in the receiver exceeds a predetermined first pressure.

A control method for a heat pump unit includes acquiring a first output capability set when the heat pump unit reaches a first preset energy efficiency ratio set at a current ambient temperature; acquiring a total demand load demanded by an indoor area having a heating demand or a cooling demand; and causing the heat pump unit to operate in accordance with the first output capability set when the total demand load is smaller than the first output capability set.

Proposed is a gas heat-pump system capable of supplying recirculation exhaust gas to an engine using an exhaust gas turbocharger and thus actively controlling an amount of the flowing recirculation exhaust gas and pressure thereof.

To control operating parameters of the compressor and ensure stable operation of the air conditioning system, a cooling medium control method for a multi-connected air conditioning system includes: acquiring current operating values of target parameters of the compressor during the operation of the compressor; calculating deviation degrees of the target parameters of the compressor according to the current operating values of the target parameters of the compressor and standard operating ranges of the target parameters of the compressor; and selectively adjusting an opening degree of the outdoor expansion valve or the indoor expansion valve based on the deviation degrees; where the standard operating ranges of the target parameters are operating ranges of the target parameters specified by a normal operating state of the compressor. Here the opening degree of the indoor expansion valve or the outdoor expansion valve is adjusted in real time according to parameters of the compressor.