Is it permissible to feed orphans in an orphanage with the intention of expiating an oath (kaffarat al-yameen), and are they considered among the poor despite the availability of charities for them?

Expiations are given only to the poor and the needy, who are those who do not have enough to suffice them. It is not permissible to give them to those who have enough, such as orphans who receive what covers their needs from social security or charities, unless they are needy and what they receive is not enough for them.