Combined system, fuel oil system and deflation and parking oil discharge method

The invention provides a combined system, a fuel oil system and a deflating and parking oil discharging method, and belongs to the technical field of aero-engines. The combined system comprises a fuel pump adjusting system, a fuel distribution system and an oil return pipeline, the fuel pump adjusting system comprises a deflation valve and a minimum pressure stop valve; the oil inlet end of the fuel pump adjusting system is respectively communicated with the deflation valve and the minimum pressure stop valve; a parking oil discharge pipeline is arranged in the minimum pressure parking valve; the deflation valve and the parking oil discharge pipeline are both communicated with the oil tank through an oil return pipeline; and the oil inlet end of the fuel oil distribution system is respectively communicated with the minimum pressure parking valve and the parking oil discharge pipeline. According to the combined system, the structure of the fuel oil system is optimized, automatic deflation and parking oil disch