I work in a similar environment to yours. Over the years I've won a few awards, some on my own nomination and some from others.
I used to feel reluctant to self-nominate. Then a few years back I heard one of my old managers say that he never nominated his staff for awards, no matter how well they'd done. His reasons aren't relevant here, but it was helpful ...
I was raised to believe that your work should speak for itself
Admittedly only two years into my career, but I have never, ever, seen that work. It certainly didn't work in university. Those who asked, got. Those who waited, wanted. I knew an acquaintance who always got two friends and went to the prof teaching the next year's classes ...
People do nominate others, you yourself have nominated others.
If these awards mean enough to you then either nominate yourself, or ask colleagues to.
Work on it's own may not be enough. If people dislike you or are jealous of you, or just don't care, then they won't nominate you however good your work is.