A catalogue of planetary nebulae chemical abundances in the Galactic bulge

In this paper, the third of a series of papers, we present well-determined chemical abundances for 124 planetary nebulae (PNe) in the Galactic bulge from deep, long-slit FORS2 spectra from the 8.2 m ESO Very Large telescope (VLT). Prior to this work there were only ~240 bulge PNe with chemical abundances previously determined over a ~50 yr period and of highly variable quality. For 34 of these PNe we are presenting their abundances for the first time, which adds ~14 per cent to the available sample of bulge PNe abundances. The interstellar reddening, physical conditions (electron densities, n_e, temperatures, T_e), and chemical compositions are derived as single values for each PN but also using different line diagnostics. Selected comparisons with the best literature fluxes for 75 PNe in common reveal that these significant new data are robust, reliable, and internally self-consistent forming the largest independent, high-quality, and well-understood derivation of PNe abundances currently available for study.