Thermoeconomical optimization of an irreversible heat engine, the Novikov plant model

In 1995, Alexis De Vos introduced a thermoeconomical analysis of a Novikov plant model considering the power output per unit of running cost of the plant exploitation as an objective function. In his study he assumed that the running costs of the plant consist of two parts: a capital cost that is proportional to the investment and, therefore, to the size of the plant and a fuel cost that is proportional to the fuel consumption. De Vos showed how the optimal efficiency smoothly increases from the maximum-power point (Curzon- Ahlborn efficiency) corresponding to energy sources where the investment is the preponderant cost up to the Carnot value (Carnot efficiency), that is, for energy sources where the fuel is the predominant cost when the heat fluxes in the Novikov model are given by a linear Newtonian heat transfer law. Later, Barranco-Jiménez and Angulo-Brown also studied a Novikov engine following the thermoeconomical approach used by De Vos, but by means of the so-called ecological optimization criterion. By means of the maximization of an objective function defined by the quotient of the characteristic functions (power output, ecological function) and the total costs considered in the performance of the power plant. In this work, we again study the thermoeconomics of a non-endoreversible simplified thermal power plant model (the so-called Novikov engine). In our study, we also take into account a cost associated to maintenance of the power plant that is proportional to the power output of the plant. In our study we consider different regimes of performance: Maximum Power Output, Maximum Efficient Power and Maximum Ecological Regime. It is shown that under ecological conditions the plant dramatically reduces the amount of heat rejected to the environment, and a loss of profits is translated in an usage of fuels that dramatically reduces the heat rejected towards the environment respect to that of a maximum power regime. Besides, we analyzed the effect on the reduction of power output in terms of an internal irreversibility.