Conventional technical thermodynamics applied to heat-to-work converters is actually a mature scientific and technological discipline. In the same way, conventional thermal cycles, as well as thermal engines exhibiting abilities to convert efficiently heat into useful work including the state of the art conventional combined cycles, are also matured technologies. This means that in practical applications it is not possible to increase significantly the efficiency of the conventional heat-to-work converters (by means of conventional technology innovation) which undergoes such conventional thermal cycles.
However, the necessity to increase the thermal efficiency of heat-to-work converters has never been as necessary as now. Nevertheless, when the heat origin is due to fossil fuels (which undergo carbon dioxide generation causing global warming) and/or non-renewable sources of heat energy, a big problem (depletion) associated with fuel availability is present.
In part, the mitigation of mentioned global warming as well as resource depletion will depend on the thermal efficiency of power plants which undergoes conventional thermal cycles. Thus, is it possible to change the paradigm of heat-to-work conversion so that heat-to-work converters increase its thermal efficiency?. This scenario is considered and treated in the book. Therefore, the aim is how to increase the thermal efficiency or how to evolve towards more efficient heat-to-work conversion technologies?.
So in order to face this paradigm shift as a dramatic challenge, we must consider that:
The degree of physical realization of the ideal thermal cycles is key to the technical feasibility of the thermal cycles considered, which compromises its implementation viability.
The XPCs type thermal cycles described so far are “ideal”, which means that in the same way that the Carnot cycle efficiency is not achievable, such ideal cycles will not be able to provide the ideal thermal efficiency due to the inherent losses associated with the irreversible thermal processes. This implies that some described thermal cycles cannot even be implemented, and/or their implementation is only possible by a distant approximation of their ideal thermal cycle.
One of the most important ways that contribute to mitigating the deterioration of the climatic environment requires that, in the same way that for some conventional thermal cycles it has been possible to evolve from Rankine cycles with a real efficiency of less than 20% to combined cycles that exceed 60%, In this book, a set of more than 40 new thermal cycles poses the challenge.
The challenge posed in this book is that, starting from the development of a group of new thermal cycles of a different nature from the conventional ones, and evolving towards designing the thermal engines capable of implementing the developed thermal cycles, it is achieved higher efficiencies than those of conventional cycles.
The set of proposed thermal cycles are characterized by closed processes and by doing useful work by means of expansion of a working fluid due to adding heat and by contraction of a working fluid due to extracting heat from the working fluid instead of rejecting heat.
Being aware of the uncertainty associated with the results obtained from the analysis of the thermal cycles developed throughout chapters 4 to 8 of the book, we encourage investigative readers to implement quantitative proofs of concept as the only reliable way towards rigorous experimental validation. Nevertheless, it has been intended a presentation quite clear and simple to understand, with a vast number of solved case studies and figures in each chapter to make the subject matter easy to a great extent.