| 摘要 |
PURPOSE:To realize a small-sized, inexpensive device and to eliminate the need for correction, by measuring differential pressure by only one differential pressure gauge even when orifices are changed over during cycle operation. CONSTITUTION:Between a heat exchanger 6 and a compressor 1, two orifices 9 and 10 and a differential pressure gauge 15 are provided. First, valves 11 and 12 provided in front of the orifices 9 and 10 are closed and the valve 14 of a by- pass pipe 13 is opened, constituting a cycle. In this case, differential pressure gate valves 19-22 are closed. Then, the differential gate valves 21 and 22 of the orifice 10 for the large quantity of flow are opened, the valve 12 is opened, and the valve 14 of the by-pass pipe 13 is closed gradually, constituting a cycle. When the quantity of flow has a margin, the valve 14 is opened, and the valves 12, 21 and 22 are closed; and the valve 11 of the orifice 9 for the small quantity of flow and the differential pressure gate valves 19 and 20 are opened, and the valve 14 is closed gradually, constituting a cycle. Consequently, a small-sized, inexpensive device is realized and correction is unnecessary. |
