A multi-temperature air conditioning system, a control method thereof and a transport refrigeration vehicle. The multi-temperature air conditioning system includes an outdoor unit; a first type indoor unit; and a second type indoor unit; a number of a first type four-way valves corresponds to the number of the first type indoor units, and a number of a second type four-way valves corresponds to the number of the second type indoor units; and a section flow path which could be conducted or disconnected is further included, which connects the first type indoor unit between the first throttling element and the first on-off valve, and connects the second type indoor unit between the second throttling element and the second on-off valve.

A heat pump system and a control method thereof. The heat pump system includes: a compressor; an indoor heat exchanger; an outdoor heat exchanger configured as an interlaced heat exchanger having at least two refrigerant flow paths; a plurality of throttling elements; and a first type four-way valve and a second type four-way valve; in a local defrosting mode, refrigerant flows sequentially from the exhaust port of the compressor through at least one of the at least two refrigerant flow paths of the outdoor heat exchanger, the throttling element, at least another of the at least two refrigerant flow paths of the outdoor heat exchanger and the suction port of the compressor.

A heat pump system includes a compressor; an indoor heat exchanger; an outdoor heat exchanger configured as an interlaced heat exchanger having at least two refrigerant flow paths; a plurality of throttling elements; and a first type four-way valve and a second type four-way valve, with ports thereof respectively connected to the inlet and the outlet of the compressor, the indoor heat exchanger, and one of the at least two refrigerant flow paths of the outdoor heat exchanger; in a local defrosting mode, refrigerant from the outlet of the compressor flows respectively through the indoor heat exchanger and at least one of the at least two refrigerant flow paths of the outdoor heat exchanger, and then sequentially through the throttling elements, at least the other of the at least two refrigerant flow paths of the outdoor heat exchanger, and the inlet of the compressor.

A heat pump system and a control method thereof. The heat pump system includes a compressor; a heat storage heat exchanger, the pipeline connection of which is configured to be disconnectable from the heat pump system; an indoor heat exchanger and an outdoor heat exchanger; a plurality of throttling elements; and a first type four-way valve and a second type four-way valve, the ports of which are respectively connected to the air inlet and the air outlet of the compressor; the unconnected ports of the first type four-way valve are respectively connected to the outdoor heat exchanger and the heat storage heat exchanger; and the unconnected ports of the second type four-way valve are respectively connected to the indoor heat exchanger and connected to the port connected to the air inlet through a capillary or on-off valve; in a combined defrosting mode, the refrigerant dissipates heat from the indoor heat exchanger and the outdoor heat exchanger respectively.

A heat pump system with a refrigerant flow path comprising, in the heating mode of operation: a compressor coupled to receive refrigerant from a heating mode first refrigerant stream and a heating mode second refrigerant stream of the refrigerant flow path; the condenser coupled to receive refrigerant from the compressor; and a heat exchanger for transferring heat between the heating mode first refrigerant stream and the heating mode second refrigerant stream, wherein the heating mode first refrigerant stream comprises: the first expansion valve coupled to receive refrigerant from the condenser; the first evaporator coupled to receive refrigerant from the first expansion valve; and the heat exchanger coupling the heating mode first refrigerant stream from the first evaporator to the compressor, wherein the heating mode second refrigerant stream comprises: the second expansion valve; the heat exchanger coupling the heating mode second refrigerant stream from the condenser to the second expansion valve; and the second evaporator being coupled to communicate refrigerant from the second expansion valve to the compressor, wherein the first evaporator is in a first air flow conduit with a first air inlet for receiving a first air flow, and the second evaporator is in a second air flow conduit coupled to receive the first air flow.

A HVAC system having an indoor heat exchanger having a first refrigerant passage extending in a first direction and a second refrigerant extending in a second direction opposite from the first direction, a first refrigerant circuit comprising a first compressor, a first expansion valve, a first outdoor heat exchanger, the first refrigerant passage, and a first reversing valve operable to control a direction of first refrigerant in the first refrigerant circuit, and a second refrigerant circuit comprising a second compressor, a second expansion valve, a second outdoor heat exchanger, the second refrigerant passage, and a second reversing valve operable to control a direction of second refrigerant in the second refrigerant circuit.

A refrigeration cycle apparatus includes a primary-side refrigerant circuit in which a first refrigerant circulates and a secondary-side refrigerant circuit in which a second refrigerant circulates. The primary-side refrigerant circuit includes a primary-side compressor, a primary-side flow path of a cascade heat exchanger, a primary-side heat exchanger, and a primary-side switching mechanism. The secondary-side refrigerant circuit includes a secondary-side compressor, a secondary-side flow path of the cascade heat exchanger, a secondary-side switching mechanism, a suction flow path, a plurality of utilization-side heat exchangers, a first connection flow path, connecting the plurality of utilization-side heat exchangers and the secondary-side switching mechanism, including a secondary-side first connection pipe, a first heat source pipe, first branch pipes, junction pipes, first connection pipes, and first utilization pipes, a second connection flow path, connecting the plurality of utilization-side heat exchangers and the suction flow path, including a secondary side second connection pipe, a second heat source pipe, second branch pipes, the junction pipes, the first connection pipes, and the first utilization pipes, a third connection flow path, connecting the plurality of utilization-side heat exchangers and the secondary-side flow path of the cascade heat exchanger, including a secondary-side third connection pipe, a fourth heat source pipe, a fifth heat source pipe, third branch pipes, second connection pipes, and second utilization pipes.

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.

An air-conditioning apparatus includes an outdoor heat exchanger. The outdoor heat exchanger includes a first heat exchanger and a second heat exchanger. A controller performs a heating operation and a heating-defrosting operation, in which one of the first heat exchanger and the second heat exchanger functions as an evaporator, an other one the first heat exchanger and the second heat exchanger functions as a condenser. When a temperature of the indoor heat exchanger by a temperature detection unit is treated as a first temperature, and a temperature of the indoor heat exchanger by the temperature detection unit is treated as a second temperature, the controller reduces a rotation speed of an indoor fan in a case where the second temperature is lower than the first temperature and where a difference between the first temperature and the second temperature is greater than or equal to a first setting value.

Double hybrid heat pumps, systems, and methods of operation that provide increased efficiency in both heating and cooling modes, heated water, and other advantages. The system includes a compressor for compressing low-pressure vapor phase refrigerant to high-pressure vapor phase refrigerant, a refrigerant condensing heat exchanger to heat water and cool the refrigerant to a high-pressure liquid refrigerant, which is provided to a refrigerant cooling heat exchanger in which any remaining high-pressure vapor phase refrigerant is condensed and the high-pressure liquid refrigerant is further cooled. The high-pressure cooled liquid refrigerant is passed through an expansion valve to drop the pressure of the cooled liquid to yield a low-pressure cooled liquid refrigerant or low-pressure cooled two-phase refrigerant. The low-pressure cooled liquid or two-phase refrigerant is then evaporated in a refrigerant evaporating heat exchanger to produce the low-pressure vapor refrigerant that is returned to the compressor.