Are the phrases: "When we reach our house, I will divorce you," and "If you do not return with me to the house today, you will never return to it," and "You have your request" - after the wife says "divorce me" - considered a triple divorce?

What you said to your wife on the first and third occasions was a threat or a promise of divorce, not an actual divorce. As for your statement to her on the second occasion, "If you do not return home with me, you will never return to it," this is an implicit divorce (kinayah talaq) that requires intention. If you intended divorce by it when she did not return, then she is divorced, and you may take her back as long as she is within her waiting period ('iddah).