  Context. Recent observations by the Extreme Ultraviolet Imager (EUI) on board
Solar Orbiter have characterized prevalent small-scale transient brightenings
in the corona above the quiet Sun termed campfires. Aims. In this study we
search for comparable brightenings in a numerical model and then investigate
their relation to the magnetic field and the processes that drive these events.
Methods. We use the MURaM code to solve the 3D radiation MHD equations in a box
that stretches from the upper convection zone to the corona. The model
self-consistently produces a supergranular network of the magnetic field and a
hot corona above this quiet Sun. For the comparison with the model we
synthesize the coronal emission as seen by EUI in its 174 {\AA} channel,
isolate the seven strongest transient brightenings, and investigate (the
changes of) the magnetic field in and around these in detail. Results. The
transients we isolate have a lifetime of about 2 minutes and are elongated
loop-like features with lengths around 1Mm to 4 Mm. They tend to occur at
heights of about 2Mm to 5Mm above the photosphere a bit offset from magnetic
concentrations that mark the bright chromospheric network and they reach
temperatures of above 1 MK. With this they very much resemble the (larger)
campfires found in observations. In our model most events are energised by
component reconnection between (bundles of) field lines that interact at
coronal heights. In one case we find that untwisting of a highly twisted flux
rope initiates the heating. Conclusions. Based on our study we propose that the
majority of campfire events found by EUI are driven by component reconnection
and our model suggests that this process contributes significantly to the
heating of the corona above the quiet Sun.
