Ecological optimization of a family of n-Müser engines for an arbitrary value of the solar concentration factor

In a recent paper (Ramírez-Moreno, González-Hernández and Angulo-Brown, 2016) it was discussed the thermodynamic performance of a family of n-Müser engines under the so-called ecological optimization criterion for finite-time heat engines. In this reference it was shown that a 4-Müser engine accomplishes the best performance in comparison with any other n-Müser engine with n≠4. However, this result was obtained for Müser engines operating under the condition of C=Cmax; that is, maximum solar concentration factor. In the present paper we show that the result previously described is also valid for arbitrary values of the concentration factor C.