  The dense environment of globular clusters (GCs) can facilitate the formation
of binary black holes (BBHs), some of which can merge with gravitational waves
(GW) within the age of the Universe. We have performed a survey of Monte-Carlo
simulations following the dynamical evolution of GCs with different masses,
sizes and binary fractions and explored the impact of the host GC properties on
the formation of BBH mergers. We find that the number of BBH mergers from GCs
is determined by the GC's initial mass, size and primordial binary fraction. We
identify two groups of BBH mergers: a primordial group whose formation does not
depend on cluster's dynamics and a dynamical group whose formation is driven by
the cluster's dynamical evolution. We show how the BBH origin affects the BBH
mergers' main properties such as the chirp mass and merging time distributions.
We provide analytic expressions for the dependence of the number of BBH mergers
from individual GCs on the main cluster's structural properties and the time
evolution of the merger rates of these BBHs. These expressions provide an
essential ingredient for a general framework allowing to estimate the merger
rate density. Using the relations found in our study, we find a local merger
rate density of 0.18$-$1.8 ${\rm Gpc}^{-3}{\rm yr}^{-1}$ for primordial BBH
mergers and 0.6$-$18 ${\rm Gpc}^{-3}{\rm yr}^{-1}$ for dynamical BBH mergers,
depending on the GC mass and size distributions, initial binary fraction and
the number density of GCs in the Universe.
