An air conditioning apparatus includes a heat exchange device that connects an outdoor unit to an indoor unit and that includes a heat exchanger configured to perform heat exchange between refrigerant and water. The heat exchanger reduces an amount of refrigerant used to perform a cooling operation or a heating operation.

Embodiments include heat pump systems with gas bypasses and related methods. In one embodiment, a system may include a gas bypass tank having a bypass inlet, a liquid outlet, and a vapor outlet, and a first splitting valve having a first splitter outlet in fluid communication with the bypass inlet, a first splitter inlet in fluid communication with the liquid outlet, and a first switching path configured to switch between a first conduit path in fluid communication with a first coil system and a second conduit path in fluid communication with a second coil system.

Embodiments include heat pump systems with gas bypasses and related methods. In one embodiment, a system may include a gas bypass tank having a bypass inlet, a liquid outlet, and a vapor outlet, and a first splitting valve having a first splitter outlet in fluid communication with the bypass inlet, a first splitter inlet in fluid communication with the liquid outlet, and a first switching path configured to switch between a first conduit path in fluid communication with a first coil system and a second conduit path in fluid communication with a second coil system.

Systems and methods for implementing ejector refrigeration cycles with cascaded evaporation stages that utilize a pump to optimize operation of the ejector and eliminate the need for a compressor between the evaporation stages.

Systems and methods for implementing ejector refrigeration cycles with cascaded evaporation stages that utilize a pump to optimize operation of the ejector and eliminate the need for a compressor between the evaporation stages.

A heat pump is provided that includes a first pipe in which a first refrigerant flows; a second pipe disposed at a side of the first pipe and in which a second refrigerant flows; a first heat exchanger connected with the first pipe and the second pipe and in which the first refrigerant exchanges heat with the second refrigerant; a boiler connected with the first pipe and in which the first refrigerant flows; a compressor connected with the second pipe and that compresses the second refrigerant; a second heat exchanger connected with the second pipe and in which the second refrigerant exchanges heat with outdoor air; a bypass pipe branched from first pipe and configured to exchange heat with the second heat exchanger; and a three-way valve that directs the first refrigerant to pass through the bypass pipe. When the outdoor heat exchanger operates as an evaporator, frost formation thereon may be prevented.

A heat pump is provided that includes a first pipe in which a first refrigerant flows; a second pipe disposed at a side of the first pipe and in which a second refrigerant flows; a first heat exchanger connected with the first pipe and the second pipe and in which the first refrigerant exchanges heat with the second refrigerant; a boiler connected with the first pipe and in which the first refrigerant flows; a compressor connected with the second pipe and that compresses the second refrigerant; a second heat exchanger connected with the second pipe and in which the second refrigerant exchanges heat with outdoor air; a bypass pipe branched from first pipe and configured to exchange heat with the second heat exchanger; and a three-way valve that directs the first refrigerant to pass through the bypass pipe. When the outdoor heat exchanger operates as an evaporator, frost formation thereon may be prevented.

An energy efficient heat pump for a heating, ventilation, and air conditioning (HVAC) system includes a vapor compression circuit, a heat exchanger of the vapor compression circuit configured to place a working fluid in a heat exchange relationship with an air flow directed across the heat exchanger, and a conduit system of the vapor compression circuit. The conduit system of the vapor compression circuit is configured to direct the working fluid into the heat exchanger and to receive the working fluid from the heat exchanger, wherein the conduit system is configured to direct the working fluid into the heat exchanger to place the working fluid in a counterflow arrangement with the air flow directed across the heat exchanger in a cooling mode of the heat pump and in a heating mode of the heat pump.

An energy efficient heat pump for a heating, ventilation, and air conditioning (HVAC) system includes a vapor compression circuit, a heat exchanger of the vapor compression circuit configured to place a working fluid in a heat exchange relationship with an air flow directed across the heat exchanger, and a conduit system of the vapor compression circuit. The conduit system of the vapor compression circuit is configured to direct the working fluid into the heat exchanger and to receive the working fluid from the heat exchanger, wherein the conduit system is configured to direct the working fluid into the heat exchanger to place the working fluid in a counterflow arrangement with the air flow directed across the heat exchanger in a cooling mode of the heat pump and in a heating mode of the heat pump.

An evaporatively cooled refrigeration system includes a refrigerant, a gas/liquid separator, an expansion valve in fluid connection to the gas/liquid separator, an evaporator to receive the refrigerant from the expansion valve, a compressor configured to compress the refrigerant in fluid connection to the evaporator, and a gas cooler in fluid connection to the compressor. The gas cooler includes an indirect heat exchanger to convey the refrigerant and facilitate heat from the refrigerant and a spray system to spray an evaporative coolant on the indirect heat exchanger. Evaporative cooling provided by the evaporative coolant on the coil is configured to cool the refrigerant below a dry bulb ambient air temperature.