Variable-frequency vacuum device for fuel gas pressure regulation

The invention discloses a variable-frequency vacuum device for fuel gas pressure regulation. The variable-frequency vacuum device comprises a condenser, a butterfly valve, a ZJP roots vacuum pump, anatmosphere ejector assembly, a water ring vacuum pump, a separator and a check valve which are connected by pipelines, wherein a vacuum breaking device is arranged on a pipeline between the ZJP rootsvacuum pump and the atmosphere ejector assembly; the condenser is also connected between the water ring vacuum pump and the separator; and the buttery valve, the ZJP roots vacuum pump, the vacuum breaking device, the atmosphere ejector assembly, the water ring vacuum pump, the separator and the check valve are arranged in a case. According to the variable-frequency vacuum device, the ZJP roots vacuum pump is used for replacing an air-cooling roots pump; the system has low energy consumption, constant pumping speed, low temperature rise, and low noise; a variable-frequency vacuum pump is used for automatically adjusting