• Energy Research

Global warming is one of the most dangerous ecological issues facing the globe. Refrigerants are a major contributor to global warming. This investigation mainly focuses on the analysis of a greener nanorefrigerant. Nanorefrigerant can improve the efficiency of refrigeration and air conditioning systems that use vapor compression. In the present investigation, mathematical and computational methods are used to assess the heat transfer and pressure drop properties of TiO2/R1234yf. In order to analyze the heat transfer characteristics and the transport features of the innovative nanorefrigerant, appropriate mathematical predictive models were adapted from earlier investigations. The models are validated by the experiments using TiO2/POE nanolubricant as a test fluid. The investigation was conducted with a temperature range of 10 °C to 40 °C and a volume percentage of nano-sized TiO2 particles in R1234yf refrigerant ranging from 0.2 to 1%. According to the research, the introduction of nanoparticles increases viscosity, thermal conductivity, and density. However, as the amount of nanoparticles rises, the specific heat capacity of the nano-enhanced refrigerant decreases. The nanorefrigerant’s heat transfer coefficient and pressure drop are improved by 134.03% and 80.77%, respectively. The outcomes observed from the predictive technique and the simulation approach had an average absolute variation of 9.91%.

Abstract The improper usage of refrigerants has a drastic impact on the environment, which is contributing to global warming and ozone layer depletion. The refrigerants which are being used currently have a very high GWP (Global Warming Potential) value that signifies an adverse impact on global warming. Refrigerant properties can be enhanced and modified by making refrigerant blends. This research uses GWP as a measure of refrigerant impact on global warming and provides alternative refrigerant blends for R32, R41, and R152a refrigerants. The results show 89.1% and 88.64% reduction in the GWP value of the R32 refrigerant blend and R152a refrigerant blend respectively. The R41 refrigerant blend has shown a reduction of 78.26%, with higher performance characteristics.

The driving motor is one of the most crucial components of an electric vehicle (EV). The most commonly used type of motor in EVs is the induction motor. These motors generate heat during operation due to the flow of electrical current through the motor’s coils, as well as friction and other factors. For long-run and high efficiency of the motor, cooling becomes more important. This article utilized ANSYS Motor-CAD to map the temperature signature of an induction motor and investigated the thermal efficiency of using nanofluids as a cooling medium. The thermal conductivity of nanofluids has been found to be superior to that of more conventional cooling fluids such as air and water. This research explores the effect of using Al2O3, ZnO, and CuO concentrations in nanofluids (water as a base fluid) on the thermal efficacy and performance of motor. According to the findings, using nanofluids may considerably increase the efficiency of the motor, thereby lowering temperature rise and boosting system effectiveness. Based on the simulation analysis using ANSYS Motor-CAD, the results demonstrate that the utilization of CuO nanofluid as a cooling medium in the induction motor led to a reduction of 10% in the temperature of the motor housing. The maximum reduction in the temperature was found up to 10% when nanofluids were used, which confirms CuO as an excellent option of nanofluids for use as motor cooling and other applications where effective heat transmission is crucial.

Abstract In this paper, discussions have been made about parabolic trough collectors, their various components and modifications implemented in those systems. It has been seen in this study, that the implementation of design modifications to absorbers, the use of various heat transfer fluids, the use of a secondary reflector as well as the use of pin fins enhance the performance of these Collectors. Furthermore, explanations have been done on the various methods and tools such as the Monte Carlo Ray Tracing method implemented while developing these improvements to the existing system. During this study, it has been observed that varieties of twisted tubes have been used which is one such advancement toward a plane tube absorber. It has been observed that the implementation of changes in the receiver tubes can lead to a system having an efficiency of around 75.5% as compared to the systems with simple tubes while modifications to the reflectors enhance the optical efficiency of the collectors by 5%. It has also been observed that the application of Twisted Tubes enhances the performance by 9.2% more than plane tubes. It has also been found that the fluids used in the absorber tubes have been experimented with wherein nanofluids have been utilized thereby resulting in increased performance. It can be concluded that the maximum thermal achieved by the MWCNT nanofluid is 22% higher than the base fluid.