Investigation of using R134a, R1234yf and R513A as refrigerant in a heat pump

The use of new generation refrigerants in heating and cooling systems operating according to vapor compression cycles and the preference of renewable energy sources is very important to reduce the negative effects on the environment. Here, the energy and exergy performance of refrigerant R450A and R1234ze, which are alternatives to R134a, were theoretically examined. Energy and exergy analysis of cooling system were performed under the same working conditions (source temperature is between -15 and 15 o C, and heat sink temperature is constant 30 o C). The COP values of R134a, R1234ze, and R450A were 2.00, 1.98 and 1.97, respectively, while the heat source temperature was -15 o C. The heat source temperature was 15 o C, the COP values of R134a, R1234ze, and R450A were 4.82, 4.83 and 4.79, respectively. Under the given operating conditions, the highest total exergy destruction occurred at R134a, while the lowest total Exergy destruction occurred at R1234ze. The refrigerant with the highest and lowest cooling capacity was R134a and R1234ze. According to the results obtained from the analysis, it was concluded that R450A and R1234ze can be used instead of R134a.

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“…101.325 kPa Table 3. Energy analysis formulations [24,25] Theoretical mass flow rate ṁr = (V ̇r ρ) suction,line…”

Section: Exergy Analysismentioning

confidence: 99%

Numerical energy and exergy analysis of cooling systems: low GWP alternative refrigerants (R450A and R1234ze) to R134a

Yildirim

Kumaş

Akyüz

2021

International Journal of Energy Applications and Technologies

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Section: Introductionmentioning

confidence: 99%

“…Increasing air volumetric flow rate obtains a higher COP and shorter drying time. Yıldız and Yıldırım (2021) investigated R134a, R1234yf, and R513A under the same operating conditions. They found that R1234yf has a high COP HP compared with R134a at the À10 C evaporator temperature, and R513A has a higher COP HP than R134a under evaporator temperatures À10 C and À5 C. Mota-Babiloni et al (2018) experimentally studied the exergy analysis of R513A and R134a, showing that the exergy efficiency of R513A was 0.4% higher than that of R134a, and R513A could replace R134a according to the second law of thermodynamics.…”

mentioning

confidence: 99%

Experimental assessment of a low GWP nonflammable new refrigerant in a closed heat pump drying system

Yang

et al. 2022

J Food Process Engineering

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Low global warming potential (GWP) refrigerants are vital to mitigating the effect of heat systems on climate change. A low GWP mixture, RGT2 (R134a/R1234yf/R161, 54%/43%/3% weight), was proposed as an alternative refrigerant for R134a in heat pump systems. This article presented the results of an experimental investigation evaluating RGT2 as a possible replacement for R134a in a closed heat pump drying (CHPD) system and studying the drying characteristics of fig slices. The experiment concluded that RGT2 has a higher coefficient of performance (COP hp ) value than R134a, on average, by 1.92%, achieving lower discharge temperature and pressure ratio at different condensing temperatures (45 C-70 C). Although the heating capacity of RGT2 was slightly lower, it still met the requirements of HPD. With careful consideration of the environment, performance, and safety, RGT2 was a suitable substitute for R134a in the drying field. In addition, the drying characteristics of fig slices were significantly affected by the air temperature. The effective diffusion coefficient (D eff ) and specific moisture extracted ratio (SMER) are increased by increasing temperature and air flow rate. The two-term model was the better model to accurately predict the fig slices drying process. The highest mean D eff and SMER of CHPDS were obtained as 6.4518 Â 10 À10 m 2 /s and 39.197 g/kWh, respectively, at the highest drying air temperature. Practical ApplicationA mixed refrigerant (RGT2) was proposed to replace R134a, and its GWP value was about 61% lower than that of R134a. Most of the studies on substituting R134a in the literature are simulations. This paper aims to evaluate the substitutions' feasibility theoretically and experimentally. The results have been assessed to provide better information about RGT2 as a potential substitute for R134a with superior comprehensive performance. Drying kinetics has also been determined experimentally, which helped to simulate fig drying. This study will provide a reference for refrigerants replacement in heat pump drying.

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“…Heat pumps offer higher efficiencies than gas boilers; however, various refrigerants perform differently in various evaporator and condenser temperatures; therefore, choosing the right refrigerant according to system description and temperature requirements is crucial [10]. Current heat pumps in the UK market utilise R410A refrigerant, which has high global warming potential (GWP 2088); however, the use of R134a (GWP 1300) and R32 (GWP675) has also been increasing [11].…”

Section: Introductionmentioning

confidence: 99%

A Comparative Environmental Assessment of Heat Pumps and Gas Boilers towards a Circular Economy in the UK

2021

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This research compares the potential environmental impacts of heat pumps with gas boilers and scenario analysis through utilising the life cycle approach. The study analyses the current situation with the baseline model and assesses future applications with Circular Economy (CE), Resource Efficiency (RE) and Limited Growth (LG) scenarios. Then, hybrid applications of low-carbon technologies and different manufacturing scenarios are investigated according to baseline and CE scenarios. Our results show that the use and manufacturing phases are responsible for 74% and 14% of all environmental impacts on average as expected. Even though the electricity mix of the UK has decarbonised substantially during the last decade, heat pumps still have higher lifetime impacts than gas boilers in all environmental categories except climate change impact. The carbon intensity of heat pumps is much lower than gas boilers with 0.111 and 0.097 kg CO2e for air source heat pumps and ground source heat pumps, whereas the boiler stands as 0.241 kg CO2e. Future scenarios offer significant reductions in most of the impact categories. The CE scenario has the highest potential with a 44% reduction for heat pumps and 27% for gas boilers on average. RE and LG scenarios have smaller potential than the CE scenario, relatively. However, several categories expect an increase in future scenarios such as freshwater ecotoxicity, marine ecotoxicity and metal depletion categories. High deployment of offshore wind farms will have a negative impact on these categories; therefore, a comprehensive approach through a market introduction programme should be provided at the beginning before shifting from one technology to another. The 50% Hybrid scenario results expect a reduction of 24% and 20% on average for ASHP and GSHP, respectively, in the baseline model. The reduction is much lower in the CE scenario, with only a 2% decrease for both heat pumps because of the reduction in heat demand in the future. These results emphasise that even though the importance of the use phase is significant in the baseline model, the remaining phases will play an important role to achieve Net-Zero targets in the future.

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Investigation of using R134a, R1234yf and R513A as refrigerant in a heat pump

Cited by 23 publications

References 21 publications

Numerical energy and exergy analysis of cooling systems: low GWP alternative refrigerants (R450A and R1234ze) to R134a

Numerical energy and exergy analysis of cooling systems: low GWP alternative refrigerants (R450A and R1234ze) to R134a

Experimental assessment of a low GWP nonflammable new refrigerant in a closed heat pump drying system

A Comparative Environmental Assessment of Heat Pumps and Gas Boilers towards a Circular Economy in the UK

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