International Journal of Heat and Mass Transfer 153 (2020) 119611 Contents lists available at ScienceDirect International Journal of Heat and Mass Transfer journal homepage: www.elsevier.com/locate/hmt Review A review of heating/cooling processes using nanomaterials suspended in refrigerants and lubricants Liu Yang a,b,c,∗ , Weixue Jiang d , Weikai Ji a,b,c , Omid Mahian e,∗∗ , Shahab Bazri e,f , Rad Sadri g , Irfan Anjum Badruddin h , Somchai Wongwises i,j a Jiangsu Provincial Key Laboratory of Solar Energy Science and Technology, School of Energy and Environment, Southeast University, Nanjing 210096, China b Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China c Engineering Research center of Building Equipment, Energy and Environment, Ministry of Education, Nanjing 210096, China d College of Electrical, Energy and Power Engineering, Yangzhou University, Yangzhou, China e School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, China f Young Researchers and Elite Club, Islamic Azad University, Mashhad Branch, Mashhad, Iran g Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50630, Malaysia h Department of Mechanical Engineering, College of Engineering, King Khalid University, PO Box 394, Abha 61421, Kingdom of Saudi Arabia i Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab. (FUTURE), Department of Mechanical Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, Bangkmod, Bangkok, Thailand j The Academy of Science, The Royal Society of Thailand, Sanam Suea Pa, Dusit, Bangkok 10300, Thailand a r t i c l e i n f o Article history: Received 1 November 2019 Revised 3 February 2020 Accepted 4 March 2020 Keywords: Boiling and condensation Heat transfer rate Thermophysical properties Nanorefrigerants Nanolubricants a b s t r a c t Over the last century, nanomaterial-based cooling/heating working fluids have been considered one of the most potent alternatives to the conventional heat transfer medium. Likewise, as one prevalent se- ries of the applications and by utilization of much more potent eco-friendly fluids, the constant every- day attempt in the area of refrigeration, HVAC, and other associated systems has involved the usage of nanorefrigerants/nanolubricants. Indeed, the addition of high thermal conductive nanoparticles to the low thermal conductive traditional base fluids is one of the most attention-grabbing areas of research. In this current scientific review article, by considering boiling, condensation, or the related phenomena, the heat transfer rate and the thermophysical properties have been targeted to investigate the substantial effect of nanoparticle addition to common refrigerants or lubricants. At the end, the relevant research gaps, namely the heat transfer rate at an atomic level, the inconsistent behavior of nanofluids, the phase change enthalpy level, and other possible fields, were detected as a helpful benchmark for future studies. © 2020 Elsevier Ltd. All rights reserved. 1. Introduction Although improving the energy efficiency of refrigeration sys- tems by employing a mixture of nanomaterials with pure con- ventional working fluids (such as refrigerants) is deemed one of the fundamental remarkable reasons to utilize nanorefriger- ants/nanolubricants, there are other vital aspects that must be noted. In this case, and to recognize the momentous role of dis- persed nanomaterials [1], the background of a variety of refrig- erants needs to be classified. Regarding the concept of different ∗ Corresponding author at: Jiangsu Provincial Key Laboratory of Solar Energy Sci- ence and Technology, School of Energy and Environment, Southeast University, Nan- jing 210096, China. ∗∗ Corresponding author. E-mail addresses: windy4ever@163.com (L. Yang), omid.mahian@xjtu.edu.cn (O. Mahian). refrigerants, from one standpoint, they can be divided into two categories. The first common group, which is called the primary refrigerants (as an unwritten basis), including chlorofluorocarbons (CFCs) and hydro-chlorofluorocarbons (HCFCs), are separated from the secondary group according to different determinative param- eters [2]. These parameters include the global warming potential (GWP), ozone depletion potential (ODP), flammability, toxicity, the phase change enthalpy level, costs, odor, metal corrosion, and so on [3–7]. However, this classification is still a bit profound. For many decades, the inert nature of some refrigerants such as HCFCs, bromofluorocarbons (BFCs), and CFCs made them accept- able choices because of their non-toxicity and non-flammability. The dilemma commenced with the awareness of their ODP and GWP, as well as their stability in the Earth’s atmosphere. These findings caused them to be replaced by the next generation of re- frigerants. Scholars and scientists introduced materials with lesser https://doi.org/10.1016/j.ijheatmasstransfer.2020.119611 0017-9310/© 2020 Elsevier Ltd. All rights reserved.