SCREW EXPANDER

摘要

In order to reduce loss due to a difference between an internal expansion ratio and an operational expansion ratio, a screw expander (1) is provided with: an internal-discharge-gas pressure detector (20) for detecting the pressure (Pf) in an expansion space measured immediately before the expansion space is connected to a gas discharge channel (9); an operation-discharge-gas pressure detector (21) for detecting the pressure (Pd) within the gas discharge channel (9); a bypass channel (13) for connecting a gas supply channel (8) and the expansion space located at a position at which the expansion space can be separated from the gas supply channel (8) and the gas discharge channel (9); a valve mechanism (10) which can shut off the bypass channel (13); and a control device (22) which closes the valve mechanism (10) when a detection value (Pf) detected by the internal-discharge-gas pressure detection means (20) is higher than or equal to a detection value (Pd) detected by the operation-discharge-gas pressure detection means (21), and which opens the valve mechanism (10) when the detection value (Pf) detected by the internal-discharge-gas pressure detection means (20) is lower than the detection value (Pd) detected by the operation-discharge-gas pressure detection means (21).