Experimental study of R134a/R410A cascade cycle for variable refrigerant flow heat pump systems

Kim, Jeonghun; Lee, Jaewan; Choi, Hwan-Jong; Lee, Sang-Hun; Oh, Saikee; Park, Warn-Gyu

doi:10.1007/s12206-015-1146-2

Cited by 17 publications

(10 citation statements)

References 10 publications

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“…The thermodynamic analysis was carried out on four refrigerant pairs, which have been believed to achieve the best performance in agreement with previous studies conducted by [4] and [10][11][12]. They are R410A/R134a, R407C/R134a, R717/R134a and R717/R600a at the specified operating condition stated in this work.…”

Section: Thermodynamic Heat Pump Assessmentsupporting

confidence: 77%

“…The previous work conducted by [4] and [10][11][12] was recalled for the present assessment where the best operating conditions and performance were attained. Hence, the following conditions were considered for the purpose of this study:…”

Section: Operating Conditionsmentioning

confidence: 99%

“…Reference [10] has pointed out that the higher COP for R410A/ R134a cascade system was obtained when the IT was in the range (40-41)°C. This behavior was observed at (7)°C ambient temperature regardless of the water inlet temperature to the high temperature condenser.…”

Section: Introductionmentioning

confidence: 99%

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Perspective Performance Evaluation Technique for a Cascade Heat Pump Plant Functions at Low Temperature Heat Source

Tarrad¹

2017

IJEEE

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Abstract:The present investigation deals with the performance assessment of Cascade heat pump plants. The overall power consumption for a Cascade system for typical heat pump characteristics was studied. Four environment friendly refrigerant pairs R717/R134a, R410A/R134a, R407C/R134a, and R717/R600a were investigated at low temperature cycle (LT) evaporator and high temperature cycle (HT) condenser temperatures of (-15 to -4)°C and (70)°C respectively. A preliminary heat pump plant is suggested to produce (500) kW heat output load as hot water demand at (65)°C with (25)°C temperature lift and a proper circulation rate. The investigation was carried out at cascade heat exchanger intermediate temperature (IT) of (33)°C and (35)°C. Sea water at (7)°C was used as a sustainable low temperature heat source and (30%) ethylene glycol-water brine at temperature of (5)°C as a thermal fluid heat carrier at the LT cycle evaporator. The evaluation of the thermal performance of the refrigerant pairs was based on a fixed heat pump extraction load at the LT cycle. The heat pump heating coefficient of performance (COP) revealed an increase fell within the range of (5-7.5)% higher than that of the plant heating COP value for the studied refrigerant pairs at the whole investigated operating conditions range. The higher IT exhibited the highest heat pump and plant heating COP than those at the lower value. R717/R600a showed the highest heating COP, lower power consumption and lower global warming potential (GWP) among other investigated refrigerant pairs. The power consumed by auxiliary pumps to circulate thermal fluid heat carriers through a heat pump may account to (4-4.5)% and (2-3)% of the extracted and output heating loads respectively, higher values could be expected for real plant. Two polynomial correlations for the assessment of the pumping power in terms of the extracted and output heating loads were derived from the present work.

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Section: Thermodynamic Heat Pump Assessmentsupporting

confidence: 77%

Section: Operating Conditionsmentioning

confidence: 99%

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Perspective Performance Evaluation Technique for a Cascade Heat Pump Plant Functions at Low Temperature Heat Source

Tarrad¹

2017

IJEEE

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“…A higher heat output with a lower intermediate temperature at the cascade heat exchanger was experienced, figure (6). A higher value for the load output of the hybrid system at (α) near (15 %) of the total load input to the system as illustrated in figure (6).…”

Section: (Ii) R717/r134a Systemmentioning

confidence: 88%

“…Experimental investigation was conducted on R134a/R410A cascade cycle for variable refrigerant flow heat pump systems by Kim et al (2015) [6]. (COP) increased up to 16% when water inlet temperature decreased.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic Analysis for Hybrid Low Temperature Sustainable Energy Sources in Cascade Heat Pump Technology

Tarrad

2017

AJET

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A thermodynamic analysis of compound Cascade refrigeration system at low temperature heat sources was conducted. The analysis was based on a target temperature of hot water at the range of (60-70) Â°C out of the heat pump. The carrier thermal fluid temperature, which provides heat at the low temperature side of the Cascade system, determines the pair of refrigerants to be implemented. A hybrid heat pump design was proposed, which implements the sea water and ground as heat sources in a compound cycle. Two of refrigerant pairs were tested for the performance and energy efficiency comparison at fixed operating conditions. In the low temperature cycle, either R410A or R717 refrigerant was allowed to circulate and R134a is circulated at the high temperature cycle. The minimum isentropic efficiency of commercially available compressors was used in this investigation, a value of (70 %) was chosen. The results of the investigation revealed that R717/R134a exhibited a higher heating (COP) than that of R410A/R134a by (3 %). The results showed that increasing the isentropic efficiency of compressors to (90 %) improved the heating (COP) by (20 %) and minimized the power consumption by (24 %). The specific power consumed by compressors of the proposed system showed a decrease of upto (3 %) lower than that of the sea water base system.

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Experimental Study on Influence of Outdoor Ambient Temperature on Heating Performance of Two-Stage Scroll Compression Air Source Heat Pump System

Chen

2020

Environmental Science and Engineering

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Experimental study of R134a/R410A cascade cycle for variable refrigerant flow heat pump systems

Cited by 17 publications

References 10 publications

Perspective Performance Evaluation Technique for a Cascade Heat Pump Plant Functions at Low Temperature Heat Source

Perspective Performance Evaluation Technique for a Cascade Heat Pump Plant Functions at Low Temperature Heat Source

Thermodynamic Analysis for Hybrid Low Temperature Sustainable Energy Sources in Cascade Heat Pump Technology

Experimental Study on Influence of Outdoor Ambient Temperature on Heating Performance of Two-Stage Scroll Compression Air Source Heat Pump System

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