Assessment of heat pump with carbon dioxide/low-global warming potential working fluid mixture for drying process: Energy and emissions saving potential

2020 ◽  
Vol 222 ◽  
pp. 113225 ◽  
Author(s):  
Baomin Dai ◽  
Pu Zhao ◽  
Shengchun Liu ◽  
Mingqiang Su ◽  
Dan Zhong ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Heat Pump ◽  
Global Warming Potential ◽  
Working Fluid ◽  
Drying Process ◽  
Fluid Mixture ◽  
Process Energy ◽  
Low Global Warming Potential

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 Optimisation of high-temperature heat pump cascades with internal heat exchangers using refrigerants with low global warming potential

Energy ◽  
2018 ◽  
Vol 165 ◽  
pp. 1248-1258 ◽  
Author(s):  
Adrián Mota-Babiloni ◽  
Carlos Mateu-Royo ◽  
Joaquín Navarro-Esbrí ◽  
Francisco Molés ◽  
Marta Amat-Albuixech ◽  
...  
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
Heat Pump ◽  
Global Warming Potential ◽  
Heat Exchangers ◽  
Internal Heat ◽  
Temperature Heat ◽  
Low Global Warming Potential ◽  
High Temperature Heat Pump

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.

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