Four-component Bogoliubov-de Gennes equations are applied to study the tunnelling conductance spectra G(E)of half-metallic ferromagnet/ferromagnet/s-wave superconductor tunnel junctions.It is found that only for noncollinear magnetizations,there exists nonzero G(E) structure within the energy gap,which is a signature of appearance of the novel Andreev reflection and spin-triplet pairing correlations.