| 摘要 |
PURPOSE:To easily control a compressor, by decreasing the variation of pressure by adjusting the quantity of winds discharged from the compressor by signals obtained by comparison operating the command value of discharge pressure and discharge pressure in place of a pressure switch. CONSTITUTION:When the pressure of a discharge air pipe 11 becomes lower than that of a pressure set instrument 1 during the operation of a compressor 10, signals from a pressure transducer 2 drop, and a PID controller 3 amplifies its negative deviation. When the value of the negative deviation becomes larger than that of a negative deviation set instrument 5, a negative deviation comparator 7 functions, the signals are input to an addition and subtraction computing element 8 and the number of capacity adjusting valves 9-1-4 that operate increases. Thus, the quantity of winds discharged from the compressor 10 augments, and the pressure of the discharge air pipe 11 rises up to set pressure. Consequently, the pressure of the compressor is modified so as to reach pressure shown in the pressure set instrument 1 centering around the value of the set instrument 1, and pressure discharged from the compressor can accurately be controlled. |
