次 embellishes you do something you can do it again and again, almost costs nothing or costs little.我上了两次厕所,打了一次篮球,去了一次网吧,and so on.
趟 embellishes something you can't do it regularly, costs high or a lot of energy.
出了一趟远门,一趟火车,
遍 embellishes something you need to do it again and again,but in fact,it is similar to 次,When do they use depends on the fixed collocation