Special Issue on Thermodynamic and Exergy Analyses of Cooling, Power, and Energy Systems

1. Introduction

Due to the energy crisis and environmental impact caused by fossil fuel energy, improving the efficiency of cooling, power, and energy systems has become one of the most important aspects of energy sectors. Furthermore, renewable energy is now heavily involved in power generation and cooling engineering. These new emerging renewable energy systems are still in the developing phase. The development of highly efficient energy systems will help to promote system applications and increase the users’ acceptance. Thermodynamic and exergy analyses provide better insight into the design, development, optimization, and performance improvement of the traditional cooling, power, and energy systems, as well as the new emerging renewable energy systems. This Special Issue aims to address the current pressing problems in the development of advanced and innovative cooling, power, and energy systems, using thermodynamic and exergy analyses.

2. Advanced Cooling, Power and Energy Systems

In light of the above, this Special Issue collected papers that investigate the thermal and operational characteristics of novel and creative systems and improved conventional cooling power and energy systems. Topics included studies on the system components and whole cycles related to the cooling, energy, and power systems. Additionally, papers that deal with the thermodynamic process of new technologies that have been proposed in order to save energy or for the purpose of environmental protection were included. Studies on system and component optimization through thermodynamic and exergy analyses for performance enhancement were also collected. A total of 21 papers were submitted to this Special Issue, and 9 papers were accepted, encompassing renewable and sustainable energy, gas turbine engines, road vehicles, heating, ventilation, and air conditioning (HVAC) systems, fuel cell technology for hydrogen production, aerodynamics and applied thermodynamics. The first paper, authored by Kim et al., (2020), presented an exergy analysis of Kalina and Kalina’s flash cycles driven by renewable energy [1]. The second paper authored by Gutierrez et al., (2020) investigated the regenerative organic Rankine cycle as a bottoming cycle of an industrial gas engine [2] and a traditional and advanced exergetic analysis was carried out. Helen et al., (2020) discussed the residue cost formation of a high-bypass turbofan engine [3]. These papers mainly focused on the improvement of power cycles. The fourth paper, authored by He et al., (2020), discussed how to improve the performance of windshield defrosters of road vehicles [4].

The Special Issue includes three papers focused on the components of refrigeration and dryer systems. The first paper by Li et al., (2020) [5] evaluated the energy and exergy efficiency of a corn dryer, which introduced a combined infrared radiation-countered flow circulation. The second paper, authored by He et al. [6], proposed a new method to investigate the refrigerant mass flow in a refrigerator using a p-V diagram. Wang et al. [7] investigated the dynamic characteristics of the reed valve in compressors based on the fluid–structure interaction method to improve the thermal performance of a compressor.

As an emerging renewable energy technology, there is intensive research on PEM fuel cell systems for hydrogen production. This Special Issue contains two papers that focused on this technology. The first paper, authored by Feng et al. [8], studied the effects of working fluids on the performance of a Roots pump for hydrogen recirculation in a PEM fuel cell system. In addition, Xing et al. [9] developed and tested a new design of a Roots pump for hydrogen recirculation in fuel cell systems. These research works can be used in future research on hydrogen fuel cell technologies.

3. Future Research

Although the Special Issue has been closed, more in-depth research on thermodynamic and exergy analyses for cooling and power systems is expected. In addition to the featured articles, Applied Sciences is committed to publishing review articles from the field of science, engineering, and technology. We strongly encourage professionals and specialists to submit review articles that summarize the latest developments, state of knowledge and applications in contemporary science, engineering, and technology fields, with a special emphasis on economic viability, safety, efficiency, and environmental sustainability.