Yes, you can take a lump sum distribution from a 529 account to pay for or reimburse all 529 qualified expenses that were or will be paid in the same year that the distribution is taken. If in January you paid $6,000 in spring semester tuition, $6,000 for room and board for your at least half-time enrolled student, $500 for textbooks and $1,800 for a computer to be used by the student, you could take one 529 distribution of $14,300 this month (or any time before the end of the year) to cover those qualified expenses. Does that answer your question?
I don't understand why you are using "personal expenses" in your example. "Personal expenses" are not a 529 qualified expense.