If you're serious - the mods won't notice anything you do until you get flagged, which sends them an alert, and even then whether or not they ban you will depend on what they consider the quality of your account, which takes into account your account's age and posting history. That's why most of HN's trolls and assholes tend to hide their most toxic comments behind green accounts. I don't know why you want to be banned, though, it won't result in your account or any of your content being deleted if that's what you're looking for. The only thing you can really do is just walk away.