scholarly journals Cycle performance evaluation of various R134a/hydrocarbon blend refrigerants applied in vapor-compression heat pumps

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881956 ◽  
Author(s):  
Liu Zhang ◽  
Jin-xiu Zhao ◽  
Li-fang Yue ◽  
Hong-xing Zhou ◽  
Chun-li Ren
Keyword(s):  
Global Warming ◽  
Heat Pump ◽  
Global Warming Potential ◽  
Mass Fraction ◽  
Heat Pumps ◽  
Cycle Performance ◽  
Hydrocarbon Fraction ◽  
Vapor Compression ◽  
Low Global Warming Potential ◽  
Cycle Efficiency

Blend refrigerants combing hydrofluorocarbons and hydrocarbons are good substitutes to decrease the flammability of hydrocarbons while reducing the global warming potential of hydrofluorocarbons. Four hydrofluorocarbon/hydrocarbon blends (R134a/R290, R134a/R600, R134a/R600a, and R134a/R1270) with various compositions are investigated in vapor-compression heat pump cycles. The effects of hydrocarbon fraction on the blend properties, including critical temperature, critical pressure, latent heat, saturated liquid line, and azeotropic behavior, are comparatively analyzed. Thermodynamic models are established for heat pump simulation. For each R134a/hydrocarbon blend, both the cooling and heating coefficient of performances generally first decrease and then increase with the hydrocarbon mass fraction. The coefficient of performances of R134a/R600 and R134a/R600a have dramatic changes within the hydrocarbon mass fraction of 0.2–1.0, while those of R134a/R290 and R134a/R1270 have dramatic changes within the fraction of 0.0–0.4. Lower condensing or higher evaporating temperatures lead to higher coefficient of performances. In addition, the volumetric capacities first increase and then decrease with the increase of hydrocarbon fraction. R134a/R290 and R134a/R1270 show much higher volumetric capacities as compared to R134a/R600 and R134a/R600a under higher hydrocarbon fractions, which can greatly reduce the required compressor size of pure R134a. The discharge temperatures are kept in the range of 43.0°C–72.3°C for all the blends. To obtain low global warming potential R134a/hydrocarbon blends, the hydrocarbon fraction need to be greater than 0.9, at which R134a/R1270 performs the best, with cooling/heating coefficient of performances of 5.25/4.70 and cooling/heating volumetric capacities of 4.78/3.53 MJ/m3. Generally, R134a/R290 and R134a/R1270 perform much better than R134a/R600 and R134a/R600a at the low global warming potential composition. This study can contribute to the determination of hydrofluorocarbon/hydrocarbon compositions based on comprehensive considerations of cycle efficiency, volumetric capacity, and low global warming potential target.

scholarly journals New HFC/HFO Blends as Refrigerants for the Vapor-Compression Refrigeration System (VCRS)

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 946
Author(s):  
Bartosz Gil ◽  
Anna Szczepanowska ◽  
Sabina Rosiek
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Mass Fraction ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Operational Parameters ◽  
Vapor Compression Refrigeration ◽  
Low Global Warming Potential ◽  
Triangular Design

In this work, which is related to the current European Parliament Regulation on restrictions affecting refrigeration, four new three-component refrigerants have been proposed; all were created using low Global Warming Potential(GWP) synthetic and natural refrigerants. The considered mixtures consisted of R32, R41, R161, R152a, R1234ze (E), R1234yf, R1243zf, and RE170. These mixtures were theoretically tested with a 10% step in mass fraction using a triangular design. The analysis covered two theoretical cooling cycles at evaporating temperatures of 0 and −30 °C, and a 30 °C constant condensing temperature. The final stage of the work was the determination of the best mixture compositions by thermodynamic and operational parameters. R1234yf–R152a–RE170 with a weight share of 0.1/0.5/0.4 was determined to be the optimal mixture for potentially replacing the existing refrigerants.

scholarly journals Energy Analysis of Vapor Compression Refrigeration Cycle Using a New Generation Refrigerants with Low Global Warming Potential

2021 ◽  
Vol 87 (2) ◽  
pp. 106-117
Author(s):  
Rabah Touaibi ◽  
Hasan Koten
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Energy Analysis ◽  
Coefficient Of Performance ◽  
Cycle Performance ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration ◽  
Low Global Warming Potential

An energy analysis study carried out on a vapor compression refrigeration cycle using refrigerants with low global warming potential (GWP) of the Hydro-Fluoro-Olefin (HFO) type, in particular R1234yf and R1234ze fluids to replace HFC refrigerants . Computer code was developed using software for solving engineering equations to calculate performance parameters; for this, three HFC type fluids (R134a, R404A and R410A) were selected for a comparative study. The results showed that R1234ze is the best refrigerant among those selected for the mechanical vapor compression refrigeration cycle. The thermodynamic analysis showed the effect of the evaporator temperature (-22 °C to 10 °C) and the condenser temperature (30 °C to 50 °C) on the steam cycle performance. Compression refrigeration, including the coefficient of performance. The results showed that the HFO-R1234ze with low GWP gives the best coefficient of performance of 3.14 close to that of the R134a fluid (3.17). In addition, R1234ze is considered an alternative fluid to R134a for their ecological properties.

scholarly journals Energy and Exergy Analysis of Low-Global Warming Potential Refrigerants as Replacement for R410A in Two-Speed Heat Pumps for Cold Climates

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5666
Author(s):  
Bo Shen ◽  
Moonis R. Ally
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Air Conditioning ◽  
Exergy Analysis ◽  
Heat Pumps ◽  
Department Of Energy ◽  
Cold Climates ◽  
Pump Design ◽  
Oak Ridge ◽  
Low Global Warming Potential

Heat pumps (HPs) are being developed with a new emphasis on cold climates. To lower the environmental impact of greenhouse gas (GHG) emissions, alternate low global warming potential (GWP) refrigerants must also replace the exclusive use of the refrigerant R410A, preferably without re-engineering the mechanical hardware. In this paper, we analyze the performance of four low-GWP alternative refrigerants (R32, R452B, R454B, and R466A) relative to the conventional R410A and draw conclusions on the relative performances for providing heating in cold climates based on the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) 210/240 standard for two-speed heat pumps. The simulations are carried using the Department of Energy, Oak Ridge National Laboratory (DOE/ORNL) Heat Pump Design Model (HPDM), a well-known heating, ventilation, and air conditioning (HVAC) modeling and design tool in the public domain and the HVAC research and development community. The results of the simulation are further scrutinized using exergy analysis to identify sources of systemic inefficiency, the root cause of lost work. This rigorous approach provides an exhaustive analysis of alternate low-GWP refrigerants to replace R410A using available compressors and system components, without compromising performance.

Transient simulation of heat pumps using low global warming potential refrigerants

2015 ◽  
Vol 21 (5) ◽  
pp. 658-665 ◽  
Author(s):  
Jiazhen Ling ◽  
Viren Bhanot ◽  
Abdullah Alabdulkarem ◽  
Vikrant Aute ◽  
Reinhard Radermacher
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Heat Pumps ◽  
Transient Simulation ◽  
Low Global Warming Potential

Experimental Evaluation on Low Global Warming Potential HFO-1336mzz-Z as an Alternative to HCFC-123 and HFC-245fa

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
Shikuan Wang ◽  
Zhikai Guo ◽  
Xiaohong Han ◽  
Xiangguo Xu ◽  
Qin Wang ◽  
...  
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Power Input ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Cycle Performance ◽  
Promising Alternative ◽  
Discharge Temperature ◽  
Low Global Warming Potential ◽  
Hcfc 123

HFO-1336mzz-Z with low global warming potential (GWP) was considered as a promising alternative of HCFC-123, HFC-245fa in air conditioning (AC) and heat pump (HP), respectively. In order to understand the operation performances of HFO-1336mzz-Z and HCFC-123, HFC-245fa in different working conditions, an experimental setup for testing the refrigeration cycle performance was built. The cycle performances of HFO-1336mzz-Z and HCFC-123 in AC conditions, HFO-1336mzz-Z and HFC-245fa in HP conditions were investigated by experiment. It was found in AC conditions, the discharge temperatures for the systems with HFO-1336mzz-Z and HCFC-123 were lower than 115 °C, the cooling capacity of the system with HFO-1336mzz-Z was 27% less than that with HCFC-123 at least, and the coefficient of performance (COP) of the system with HFO-1336mzz-Z was 0.1 lower than that with HCFC-123; in HP conditions, the discharge temperature with HFO-1336mzz-Z was lower than that with HFC-245fa, the former was never over 115 °C while the latter was up to 126 °C, the power input to the compressor with HFO-1336mzz-Z was 20% less than that with HFC-245fa in the same HP conditions, the heating capacity of the system with HFO-1336mzz-Z was 30–40% less than that with HFC-245fa.

Sign in / Sign up

Export Citation Format

Share Document