From what I understand there is not necessarily a maximum number of orgasims a female may have in one hour but instead a number until she becomes dry making sex rather uncomfortable for her. Also there is no definite answer sense it will change from woman to woman depending on numerous of physical and chemical differences they have. On average I've found a majority of woman have 5-20 in one hour and in some cases 30+, this all depends on the performance of her partner, the position used, and her emotional state.
I have no proper education about female sexuality nor am I a doctor so none of what I stated should be taken as fact, this is just what I've noticed and gathered from personal experience.