A refrigeration cycle apparatus includes a refrigerant circuit and refrigerant. The refrigerant is a zeotropic mixed refrigerant. At least one of the condenser and the evaporator has a first heat exchange unit located windward and a second heat exchange unit located leeward in a first direction in which air flows. Each of the first heat exchange unit and the second heat exchange unit has an inflow passage and an outflow passage for the refrigerant that are located in a plurality of stages arranged in the second direction crossing the first direction. The refrigerant flows out from the outflow passage of the second heat exchange unit into the inflow passage of the first heat exchange unit. The outflow passage of the second heat exchange unit is located in the same stage as the outflow passage of the first heat exchange unit in the second direction.

An HVAC system includes an evaporator, a condenser, a compressor. A first refrigerant path flows through a first expansion valve, first evaporator inlet, within the evaporator, and out of the evaporator through a first evaporator outlet. A second refrigerant path flows through a second expansion valve, a second evaporator inlet, within the evaporator, and out of the evaporator through a second evaporator outlet. Refrigerant flows from the condenser to the first refrigerant path and the second refrigerant path, and from the first refrigerant path and the second refrigerant path to the compressor.

A heat exchanger assembly (100), the heat exchanger assembly (100) comprising: a first heat exchanger (1), the first heat exchanger (1) comprising a first communicating header pipe (10), a first header pipe (12), and heat exchange tubes (9) arranged between the first communicating header pipe (10) and the first header pipe (12); and a second heat exchanger (2), the second heat exchanger (2) comprising a second communicating header pipe (20), a second header pipe (22), and heat exchange tubes (9) arranged between the second communicating header pipe (20) and the second header pipe (22), wherein the first communicating header pipe (10) is provided with a partition plate (30) and thus has a plurality of first communicating chambers (14) arranged in the axial direction of the first communicating header pipe (10), the second communicating header pipe (20) is provided with a partition plate (30) and thus has a plurality of second communicating chambers (24) arranged in the axial direction of the second communicating header pipe (20), and the plurality of first communicating chambers (14) are in fluid communication with the corresponding plurality of second communicating chambers (24), such that a refrigerant entering the heat exchanger assembly (100) successively enters the second heat exchanger (2) and the first heat exchanger (1) in series. The heat exchange capability of the heat exchanger assembly (100) can be effectively improved.

A heat exchanger includes heat exchange fins, refrigerant pipes are arranged across the heat exchange fins, and connecting pipes connected to the refrigerant pipes to thereby define refrigerant passages. The connecting pipes include a first pipe portion having a first end connected to one of the refrigerant pipes, a branch pipe portion that is branched from the first pipe portion, that extends parallel to the first pipe portion, and that is connected to another of the refrigerant passages, and a second pipe that is connected to the first pipe portion and that is configured to guide gas-phase refrigerant separated from the refrigerant in the first pipe portion. The second pipe includes an inner insert portion inserted into a second end of the first pipe portion and an outlet portion that extends from the inner insert portion in direction opposite to the second end of the first pipe portion.

An air-conditioning unit is provided, comprising: an input vent for receiving return air; an intermediate vent; an output vent; a blower fan proximate to the input vent for moving the return air from the input vent to the intermediate vent; and an air-conditioner coil between the intermediate vent and the output vent including an active portion including one or more operational air-conditioning coils that receive a first portion of the return air from the intermediate vent, for circulating a coolant, condition the first portion of the return air by heat exchange with the coolant to create conditioned air, and pass the conditioned air to the output vent, and an inactive portion that does not circulate coolant and passes a second portion of the return air as unconditioned air to the output vent, wherein the conditioned air and the unconditioned air pass through the output vent as supply air.

A liquid-cooling radiator module includes a first reservoir, a second reservoir, a heat dissipation stacked structure, a radiator inlet and a radiator outlet. The first reservoir includes a first chamber and a second chamber. The second reservoir includes a third chamber and a fourth chamber. A fin tube layer of the heat dissipation stacked structure is sandwiched between the first reservoir and the second reservoir. The radiator inlet is connected to the first reservoir and the first chamber. The radiator outlet is connected to the second reservoir and the fourth chamber. A part of fin tubes of the fin tube layer communicates with the first chamber and the third chamber, another part of the fin tubes communicates with the third chamber and the second chamber, and one another part of the fin tubes communicates with the second chamber and the fourth chamber.

Apparatus, systems, and methods for a modular heating unit that may be adapted to be inline with a pipeline. The unit includes a base member having a main inlet pipe, a header, and pipes connecting the main inlet pipe with the header. A combustion chamber is positioned within the pipes. One or more heat exchangers are connected to the header. The heat exchangers each having a top surface, bottom surface, plurality of fins, inlet ring, inlet port, outlet ring, and outlet port. The modular heating unit includes external inlet and outlet pipes. A first flow path enables fluid to flow from the header into the one or more heat exchangers. An exit flow path connected to the external outlet pipe connects the one or more heat exchangers to an exit port with a portion of the exit flow path being positioned above the one or more heat exchangers.

A heat exchanger includes a vapor collection pipe, a liquid collection pipe, and an exchange pipeline. The exchange pipeline includes a condensing section, an evaporation section, and a transition section. An upper end of the condensing section is connected to the vapor collection pipe. A lower end of the condensing section is connected to a first end of the transition section. An upper end of the evaporation section is connected to a second end of the transition section. A lower end of the evaporation section is connected to the liquid collection pipe. The evaporation section and the condensing section respectively extend in directions opposite to each other.

A heat exchanger satisfies Expression (1) below, where the number of the main heat transfer tubes is represented as N.sub.1, and the number of the sub-heat transfer tubes is represented as N.sub.2. In this heat exchanger, the main heat exchanger satisfies Expressions (2) and (3) below, while the sub-heat exchanger satisfies Expressions (4) and (5) below.

0.1<N.sub.2(N.sub.1+N.sub.2)<0.4  (1)

0.03<Ta.sub.1/Ha.sub.1<0.3  (2)

0.03<Ta.sub.2/Ha.sub.2<0.3  (3)

AT.sub.1<Gr.sub.1/(G×D.sub.1(ρL.sub.1−ρG.sub.1)).sup.(1/2)×(X.sub.1.sup.(1/2)×ρG.sub.1.sup.(−1/4)+(1−X.sub.1).sup.(1/2)×ρL.sub.1.sup.(−1/4)).sup.2  (4)

AT.sub.2<Gr.sub.2/(G×D.sub.2(ρL.sub.2−ρG.sub.2)).sup.(1/2)×(X.sub.2.sup.(1/2)×ρG.sub.2.sup.(−1/4)+(1−X.sub.2).sup.(1/2)×ρL.sub.2.sup.(−1/4)).sup.2  (5)

Provided is a heat exchanger to perform heat exchange with a predetermined apparatus, the heat exchanger including a heat exchange channel construction configured to form a heat exchange area for heat exchange with the apparatus and to perform heat exchange through a flow of a heat transfer medium. The heat exchange channel construction includes a plurality of heat exchange channels each in a spiral shape, and the heat exchange channel construction includes an independent channel heat exchange area in which one of a first heat exchange channel and a second heat exchange channel included in the plurality of heat exchange channels independently performs heat exchange in a structure that includes at least one of a single channel structure and a branch channel structure and an interlocked heat exchange area in which the first heat exchange channel and the second heat exchange channel perform heat exchange through interlocking.