Investigation on The Chlorine Free Hfc Refrigerants

Introduction

Investigation on chlorine-free HFC refrigerants aims to leverage the advantages of both HFC and HCFC. This has led to new studies on blending hydrofluorocarbons, resulting in the formation of new gases such as R507A and R417A. However, not all blend mixtures are suitable replacements for existing refrigerants because the Global Warming Potential (GWP) of the mixed refrigerant must be lower than the currently used refrigerant. Among these blends, R417A has shown promising results, demonstrating the capacity to replace R22 in current applications. Notably, R417A consumes less power than R22 when tested under identical apparatus and operating conditions.

Composition and Performance of R417A

Refrigerant R417A is composed of R125, R134, and R600. Binit Kumar Jha (n.d.) conducted a theoretical study comparing the eco-friendly R600a refrigerant and the widely used R134a refrigerant, observing that the discharge pressure of R600 is lower than that of R134a. Additionally, the refrigerant effect and the coefficient of performance are comparatively higher for R600a than R134a. These findings suggest that R417A could be an effective alternative in applications seeking to reduce environmental impact.

Experimental Studies on Refrigerant Blends

Adil F. Momin and Manish H. Attal (n.d.) carried out experimental tests on a domestic refrigerator using phase change materials (PCM) with an R290/R600a blend as a refrigerant. The PCM used was ethylene glycol, coated on the backside of the evaporator. The addition of PCM enhances heat transfer and elevates evaporating temperatures. Thermal energy stored in the PCM is utilized during off cycles, aiding continuous refrigeration operation. This leads to an increase in the coefficient of performance and a decrease in refrigerant cycling time. Such enhancements underscore the potential of PCM in improving the efficiency of refrigerant systems.

Search for R134a Alternatives

Research to find a replacement for refrigerant R134a has been conducted by several researchers. Prayudi and Roswati Nurhasanah (n.d.) analyzed the performance of R600a and R134a refrigerants with the subcooling effect using liquid suction heat exchangers under various cooling loads. Cooling load variations were achieved by opening the valve at different positions, revealing no impact on compressor work due to cooling load. However, compressor work increased with the subcooling effect. Greater subcooling temperatures result in a larger temperature drop in the evaporator, with R600a delivering better results compared to others.

Effectiveness of Subcooling

Prayudi Suparmin (n.d.) conducted an experimental analysis on different refrigerants for varying degrees of subcooling. He utilized a liquid suction heat exchanger for different degrees of subcooling, indicating that subcooling the refrigerant tends to prevent flash gas formation at the throttle valve. His experiments demonstrated that the effectiveness of the liquid suction heat exchanger (LSHE) increases with a higher degree of subcooling. The study highlighted that a mixture of R290 and R600a in a 50:50 ratio within a refrigeration system exhibited the highest effectiveness of LSHE compared to other refrigerants. Such insights emphasize the importance of subcooling in optimizing refrigerant systems for better performance and efficiency.

Conclusion

In conclusion, the ongoing investigation into chlorine-free HFC refrigerants, particularly R417A, presents promising alternatives to traditional refrigerants like R22 and R134a. The benefits of enhanced energy efficiency and reduced environmental impact make these new blends attractive options for the future of refrigeration technology. As research continues, the development and adoption of eco-friendly refrigerants will play a crucial role in mitigating climate change and promoting sustainable practices in the industry.

References

Binit Kumar Jha. (n.d.). Theoretical study between eco-friendly R600a refrigerant and widely used R134a refrigerant.

Adil F. Momin & Manish H. Attal. (n.d.). Experimental tests on domestic refrigerator using phase change materials with R290/R600a blend as refrigerant.

Prayudi & Roswati Nurhasanah. (n.d.). Performance analysis of R600a and R134a refrigerants with subcooling effect.

Prayudi Suparmin. (n.d.). Experimental analysis on different refrigerants for varying degree of subcooling.