It could be Yuzu that you have?
very sour and bitter but it's good when you mix the juice with soy sauce and use it as a dressing
The one in my pic isn't though and the fruit is actually for viewing only (that's why my mom used it for her flower arrangement), they are not meant to be eaten but I got curious and ate some and put them in my smoothie.
Oh actually, yours looks a lot smaller than the Yuzu tree. Prolly one of those viewing only kind of orange tree then. But I'd still eat them. hehe