Abstract: To provide a vehicle air-conditioning apparatus which can ensure a dehumidifying ability even during an intermediate thermal load time where an outside air temperature becomes high during a dehumidifying heating operation time. In a vehicle air-conditioning apparatus, at least a compressor 6, a first heat exchanger 2, a first refrigerant control part 9 which is formed by connecting a first expansion device 7 and a first open/close valve 8 in parallel to each other, a vehicle exterior heat exchanger 4, a second refrigerant control part 13 which is formed by connecting a second expansion device 12 and a second open/close valve 11 in series, and a second heat exchanger 3 are connected in the preceding order in a loop.

Abstract: To provide a vehicle air-conditioning apparatus which can ensure a dehumidifying ability even during an intermediate thermal load time where an outside air temperature becomes high during a dehumidifying heating operation time. In a vehicle air-conditioning apparatus, at least a compressor 6, a first heat exchanger 2, a first refrigerant control part 9 which is formed by connecting a first expansion device 7 and a first open/close valve 8 in parallel to each other, a vehicle exterior heat exchanger 4, a second refrigerant control part 13 which is formed by connecting a second expansion device 12 and a second open/close valve 11 in series, and a second heat exchanger 3 are connected in the preceding order in a loop.

Abstract: A heat exchanger 1 includes at least a plurality of tubes 2 and an upper tank 4 communicating with an upper end portion of a tube group formed by the tubes 2 so as to distribute coolant along the up/down direction. The coolant flows in through an inflow port 9 located at the upper tank 4 in the heat exchanger 1. An open-top coolant intake guide passage 25 is disposed at the inflow port 9 and the coolant intake guide passage 25 is thus inserted at the upper tank 4. With this configuration, coolant flowing at a very low flow rate has improved distribution, and uniformity in the output air temperature is achieved, while ensuring that the structure does not create excessive resistance against the coolant flow at a high flow rate.

Abstract: The object of this invention is to improve the distribution of coolant flowing at a very low flow rate and achieve uniformity in the output air temperature while ensuring that the structure does not create excessive resistance against the coolant flow at a high flow rate. A heat exchanger 1 includes at least a plurality of tubes 2 and an upper tank 4 communicating with an upper end portion of a tube group formed by the tubes 2 so as to distribute coolant along the up/down direction. The coolant flows in through an inflow port 9 located at the upper tank 4 in the heat exchanger 1. An open-top coolant intake guide passage 25 is disposed at the inflow port 9 and the coolant intake guide passage 25 is thus inserted at the upper tank 4.

Abstract: In a freezing cycle, if the pressure in a high-pressure line (8) reaches an abnormal level, the high-side pressure is released toward a low-pressure line (9) to lower the pressure without releasing the coolant into the atmosphere and the coolant is released into the atmosphere only when the pressure in the low-pressure line (9) reaches an abnormal level.

Abstract: In a laminated heat exchanger with a pair of tank portions formed at one side of each tube element and intake/outlet portions for heat exchanging medium provided at one end in the direction of the lamination or in the direction running at a right angle to the direction of the lamination, a constricting portion for limiting the flow passage cross section is provided in an area in the tank portions where the flow shifts from an even-numbered pass to an odd-numbered pass in a plurality of passes. This allows the heat exchanging medium to flow in sufficient quantities into the tube elements near the outlet side of the partitioning portion, preventing inconsistency in temperature distribution. This constricting portion, which is formed in the tank group opposite the tank group where the partitioning portion is provided, is provided at the same lamination position as the partitioning portion. The constricting portion may be also formed with a plurality of holes.

Abstract: In a laminated heat exchanger with a pair of tank portions formed at one side of each tube element and intake/outlet portions for heat exchanging medium provided at one end in the direction of the lamination or in the direction running at a right angle to the direction of the lamination, a constricting portion for limiting the flow passage cross section is provided in an area in the tank portions where the flow shifts from an even-numbered pass to an odd-numbered pass in a plurality of passes. This allows the heat exchanging medium to flow in sufficient quantities into the tube elements near the outlet side of the partitioning portion, thereby avoiding inconsistency in temperature distribution. This constricting portion, which is formed in the tank group opposite the tank group where the partitioning portion is provided, is provided at the same lamination position as the partitioning portion. The constricting portion may be also formed with a plurality of holes.