Abstract: A fin (3) of a fin-tube heat exchanger (1) has protuberances (5) each disposed between two adjacent heat transfer tubes (2, 2) and holes 8 (cut-outs) each formed upstream of the protuberances (5). Each of the protuberances (5) has, as an upstream portion adjacent to the hole (8), a wing portion (6) tapering toward an upstream side.

Abstract: A fin-tube heat exchanger has a plurality of fins (3) arranged parallel to and spaced from each other at a predetermined gap, and a plurality of heat transfer tubes (2) penetrating the fins (3). In each of the fins (3), a first cut-and-raised portion (5a), a second cut-and-raised portion (5b), and a third cut-and-raised portion (5c) are formed in that order by cutting and raising a portion of the each of the fins so as to turn it over from an upstream side to a downstream side. The horizontal cross-sectional shape of each of the first cut-and-raised portion (5a), the second cut-and-raised portion (5b), and the third cut-and-raised portion (5c) is formed in a semicircular shape and curved so as to taper toward the upstream side.

Abstract: A refrigerating machine includes a compressor for compressing a refrigerant, a radiator for radiating heat from the refrigerant discharged from the compressor, an expander for expanding the refrigerant discharged from the radiator, and an evaporators for evaporating the refrigerant discharged from the expanders, all connected in series. The refrigerating machine also includes a refrigerant flow regulator for regulating the amount of refrigerant flowing into the expander and a controller for controlling the compressor and the refrigerant flow regulator. At a stop of the compressor, the controller controls the refrigerant flow regulator to reduce the amount of refrigerant flowing into the expander.

Abstract: A refrigeration cycle apparatus includes a compressor, a radiator, an expander, an evaporator, a bypass circuit, and an injection circuit. The bypass circuit has a flow rate control valve and a gas-liquid separator. One end of the bypass circuit is connected to an intake conduit of the expander and the other end thereof is connected to a discharge conduit of the expander so that a portion of refrigerant passed through the radiator bypasses the expander and is guided to the flow rate control valve and that the liquid refrigerant separated by the gas-liquid separator returns to the discharge conduit of the expander. One end of the injection circuit is connected to a gas outlet portion of the gas-liquid separator and the other end thereof is connected to an intermediate pressure portion of the compressor.