An air conditioner includes an outdoor unit in which a refrigerant circulates; an indoor unit in which water circulates; a heat exchange device including a heat exchanger that connects the outdoor unit to the indoor unit and performs heat exchange between the refrigerant and the water; a first outdoor unit connection pipe configured to connect the outdoor unit and the heat exchange device, a high-pressure gaseous refrigerant flowing in the first outdoor unit connection pipe; a second outdoor unit connection pipe configured to connect the outdoor unit and the heat exchange device, a low-pressure gaseous refrigerant flowing in the second outdoor unit connection pipe; a third outdoor unit connection pipe configured to connect the outdoor unit and the heat exchange device, a liquid refrigerant lowing in the third outdoor unit connection pipe; a bypass pipe configured to communicate the third outdoor unit connection pipe and the second outdoor unit connection pipe; and a bypass valve provided in the bypass pipe.

The disclosed technology includes systems and methods of reducing frost accumulation on a heat pump evaporator coil. The disclosed technology can include a heat pump assembly having an evaporator coil, a fan configured to direct air across the evaporator coil, a temperature sensor, and a controller configured to energize the fan to direct air across the evaporator coil when the temperature of the evaporator coil is below a threshold temperature.

An air conditioner includes an indoor unit, an outdoor unit, and a controller. The outdoor unit is connected to the indoor unit, and the outdoor unit includes a housing, a compressor, a four-way valve, an outdoor fan, a separating device, and a plurality of outdoor heat exchangers arranged in parallel. The controller is coupled to the compressor, the four-way valve, the outdoor fan, and the driving assembly, and is configured to control a first portion of a refrigerant flowing out from the compressor to flow into an outdoor heat exchanger; control a second portion of the refrigerant flowing out from the compressor to flow into the indoor unit; and when a time in which the first portion of the refrigerant flows into the outdoor heat exchanger is less than a first preset time, prevent a refrigerant flowing out from the indoor unit from flowing into the outdoor heat exchanger, and control the driving assembly to drive the wind blocking portion to move, so as to separate the outdoor fan from the outdoor heat exchanger.

A refrigeration cycle device includes a third refrigerant passage connecting a utilization heat exchanger to a first expansion valve, a fourth refrigerant passage connecting the first expansion valve to a receiver, a fifth refrigerant passage connecting the receiver to a second expansion valve, a sixth refrigerant passage connecting the second expansion valve to an air heat exchanger, a hot-gas bypass passage connecting a discharge passage to the sixth refrigerant passage, a hot-gas bypass valve, an internal heat exchanger to exchange heat between the liquid refrigerant inside the receiver and the refrigerant passing through the suction passage, a liquid bypass passage including an inlet portion connected to the fourth refrigerant passage, the fifth refrigerant passage, or a lower portion of the receiver, and an outlet portion connected to the suction passage upstream of the internal heat exchanger, and a liquid bypass valve.

An air-conditioning apparatus includes a selection unit and a determination unit, the selection unit selecting a reverse-defrosting operation mode or a heating-defrosting simultaneous operation mode, the reverse-defrosting operation mode being a mode in which all of parallel heat exchangers are defrosted by stopping a heating operation, the heating-defrosting simultaneous operation mode being a mode in which each parallel heat exchanger is sequentially defrosted while continuing a heating operation, the determination unit determining whether or not a defrosting operation is to be started, in which the determination unit is configured to start the defrosting operation in a state where the amount of frost deposited on the parallel heat exchangers is smaller in a case where the heating-defrosting simultaneous operation mode is selected than in a case where the reverse-defrosting operation is selected.

The invention relates to a method for real-time performance check of transport refrigeration units comprising the steps of: comparing via controller temperature sensors by pairs and determining from these comparisons by pairs if one or more temperature sensors are defective or in some extent deviates from expected temperature readings; at the same time measuring/monitoring the mass flow of cooling agent through a compressor and through an evaporator expansion valve V.sub.exp which the controller by comparison determines if mass flow through the compressor do not deviate more than 25% from the mass flow through that evaporator expansion valve V.sub.exp; if said deviation of mass flow through the compressor is more than 25% different from said mass flow through the expansion device V.sub.exp, an error signal is provided

The present invention describes a vapour compression apparatus wherein an intermediary located heat battery is capable of releasing charge (i.e. discharging) and/or charging and thereby controlling the temperature of a heat source or heat sink temperature in a vapour compression cycle. More particularly, the present invention describes vapour compression apparatus wherein an intermediary located heat battery comprising Phase change material (PCM) is capable of releasing charge (i.e. discharging) energy and/or charging and thereby controlling the temperature of a heat source and/or heat sink temperature in a vapour compression cycle in a range of refrigeration and/or heating systems including: air conditioning in both domestic and industrial uses; transportation of food/materials in vehicles, trains, air, etc. The present invention also relates to a methodology for selecting phase change materials (PCMs) and/or refrigerants for a vapour compression apparatus.

Provided is a heat pump device capable of efficiently adjusting the temperature in a buffer tank for collecting or discharging a refrigerant in a high-pressure space of a refrigerant circulation circuit.

Disclosed is a heat pump device in which a compressor, a gas cooler, a refrigerant heat exchanger, a refrigerant expansion valve, and an evaporator are connected to configure a refrigerant circulation circuit, wherein the heat pump device includes a buffer tank, one end of which is connected to the high-pressure side of the refrigerant expansion valve and arranged to store a refrigerant, and a first refrigerant pipe, one end of which is connected to the high-pressure side of the compressor and the other end of which is connected to the low-pressure side of the evaporator and arranged to exchange heat with the buffer tank, wherein the first refrigerant pipe includes a first control valve arranged between the high-pressure side of the compressor and the buffer tank to control the opening and closing of the first refrigerant pipe, and a first flow rate regulator arranged between the buffer tank and the low-pressure side of the evaporator to control the flow rate of the refrigerant.

Disclosed therein are a heat pump system for a vehicle and a method of controlling the heat pump system, which determines that frosting begins on an exterior heat exchanger and carries out a defrosting control if a difference value between outdoor temperature and refrigerant temperature of an outlet side of the exterior heat exchanger is above a frosting decision temperature in a heat pump mode, thereby increasing frost-prevention and defrosting effects and enhancing heating performance and stability of the system because the system recognizes the beginning of frosting on the exterior heat exchanger at a proper time so as to carry out the defrosting control.

A system for deicing an external evaporator for heat pump systems includes at least one compressor, at least one internal condenser, at least one external evaporator, at least one liquid separator, and a system of ducts for cooling fluid. The deicing system includes a secondary refrigeration circuit, which includes a tank for storing a heat transfer fluid, and a first heat exchanger immersed in the heat transfer fluid and adapted to transfer heat to the heat transfer fluid by cooling the cooling fluid. The system further includes a bypass refrigeration circuit, which includes the tank, and a second heat exchanger immersed in the heat transfer fluid and adapted to absorb heat from the heat transfer fluid by heating the cooling fluid. The system also includes a deicing circuit adapted to convey cooling fluid.