A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
An investigation of R417a as a drop-in alternative for R22 in a residential heat pump
The paper is in an effort to investigate the drop-in application of R417a in a residential heat pump system designed for R22. The detailed work includes the analysis of thermodynamic cycle, heat transfer, and experimental testing. In the experimental study, R417a is used as a drop-in replacement for air conditioning and heat pump applications without modifying equipment or switching to synthetic oil. Both heating-mode and cooling-mode operation were tested in a nominal 2-ton split heat pump system using R22 and R417a. Based on the analysis of thermodynamic cycle, R417a can't achieve the better theoretical COP than R22 while its capacity is quite lower than R22. The further heat transfer analysis also indicates that the heat transfer performance of R417a is worse than R22, R407c, and R410a. The testing results of R417a show that the cooling and heating COPs of R417a are 11-15% and 0-12% lower, respectively, than those of R22. The capacity of R417a is only 80-88% of that of R22. Therefore, it takes a longer running time for the R417a system to achieve the desired room temperature. However, the discharge temperature of R417a is much lower than that of R22. Compared with past research, it shows that the COP of R417a could be just equivalent to or slightly higher than that of R407c. But the unique advantage of R417a is that R417a does not require any equipment modification or a switch to synthetic oil if it is served as a drop-in replacement in the equipment designed for R22. The testing results illustrate there is no necessary to concern about compressor burnout if R417a is filled directly into equipment designed for R22. Therefore, R417a is a suitable candidate as a drop-in low-cost replacement with the certain penalty of energy efficiency for existing R22 systems. If R417a is to serve as a long-term replacement for R22, a new optimized system for 417A is necessary, and further research is also needed on the operating behavior of R417a in such an optimized system.
An investigation of R417a as a drop-in alternative for R22 in a residential heat pump
The paper is in an effort to investigate the drop-in application of R417a in a residential heat pump system designed for R22. The detailed work includes the analysis of thermodynamic cycle, heat transfer, and experimental testing. In the experimental study, R417a is used as a drop-in replacement for air conditioning and heat pump applications without modifying equipment or switching to synthetic oil. Both heating-mode and cooling-mode operation were tested in a nominal 2-ton split heat pump system using R22 and R417a. Based on the analysis of thermodynamic cycle, R417a can't achieve the better theoretical COP than R22 while its capacity is quite lower than R22. The further heat transfer analysis also indicates that the heat transfer performance of R417a is worse than R22, R407c, and R410a. The testing results of R417a show that the cooling and heating COPs of R417a are 11-15% and 0-12% lower, respectively, than those of R22. The capacity of R417a is only 80-88% of that of R22. Therefore, it takes a longer running time for the R417a system to achieve the desired room temperature. However, the discharge temperature of R417a is much lower than that of R22. Compared with past research, it shows that the COP of R417a could be just equivalent to or slightly higher than that of R407c. But the unique advantage of R417a is that R417a does not require any equipment modification or a switch to synthetic oil if it is served as a drop-in replacement in the equipment designed for R22. The testing results illustrate there is no necessary to concern about compressor burnout if R417a is filled directly into equipment designed for R22. Therefore, R417a is a suitable candidate as a drop-in low-cost replacement with the certain penalty of energy efficiency for existing R22 systems. If R417a is to serve as a long-term replacement for R22, a new optimized system for 417A is necessary, and further research is also needed on the operating behavior of R417a in such an optimized system.
An investigation of R417a as a drop-in alternative for R22 in a residential heat pump
Untersuchung des Kältemittels R417a als Alternative für R22 in einer Wohnhauswärmepume
Gao, Zhiming (author) / Mei, Viung C. (author) / Chen, Fang C. (author) / Tomlinson, John (author)
2006
10 Seiten, 8 Bilder, 1 Tabelle, 15 Quellen
Conference paper
English
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