Patent attributes
An evaporator includes a first descending flow tube group provided between a first upper header and a first lower header, and a second descending flow tube group provided between a second upper header and a second lower header to be located windward of the first descending flow tube group. The first upper header includes a first compartment communicating with the upper end of the first descending flow tube group, and the second upper header includes a third compartment communicating with the upper end of the second descending flow tube group. A first flow distribution control section having a first refrigerant passage section for communication between the first and third compartments is disposed between these compartments. The area of a portion of the first refrigerant passage section on the upstream side is larger than the area of a portion of the first refrigerant passage section on the downstream side.