| 摘要 |
PURPOSE:To enhance the comfortability of drive, by connecting two throttle valves between a condenser and an evaporator in a cooling circuit, and by connecting the part between the two throttle valves with a coolant compressor through a bypass pipe having a motor driven second coolant compressor, and by controlling the turn-on and -off of the second compressor and the throttle valve in the vicinity of the evaporator. CONSTITUTION:During cooling operation, a first throttle valve 10 is normally maintained to be turned off so that the stream of coolant through the valve 10 exhibits a steady-state condition as is in a cooling circuit 6. Further, when the engine 1 rotates at a low rotational speed, a switch 16 is turned on to throttle the first throttle valve 10, and to drive a second coolant compressor 13. Accordingly, coolant is led in a vapor-gas mix condition into a liquid receiver 8. Coolant gas in the receiver 8 is sucked into the second compressor 13 through a bypass pipe 12 and is therefore compressed and discharged to be merged into coolant discharged from a first compressor 5 so that it is finally returned into the cooling circuit 6. With this arrangement, it is possible to fill liquid coolant in an evaporator 9, and therefore, it is possible to prevent the capacity of cooling from being insufficient and to enhance the comfortability of drive of the vehicle. |
