Theoretical study of a high-temperature heat pump system composed of a CO 2 transcritical heat pump cycle and a R152a subcritical heat pump cycle

Yang, Wenbo; Cao, Xing-qi; He, Ya-Ling; Yan, Feiyu

doi:10.1016/j.applthermaleng.2017.03.098

Cited by 44 publications

(19 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These equations are expressed with dimensionless parameters using the nominal operating case (see Table 2 for the exact values) in order to create more general conclusions. The accuracy of these equations is higher with R 2 equal to 99.19% for Equation (18) and 96.47% for Equation (19).…”

Section: Deeper Analysis Of the Examined Heat Pumpmentioning

confidence: 99%

“…For this reason, the operating scenarios of Figures 16 and 17, under constant COP, are examined mathematically in order to develop proper correlations. Equation (18) correlates the cooling capacity with the rotational speed and the ambient temperature, while the equation correlates the COP with the same parameters. These equations are expressed with dimensionless parameters using the nominal operating case (see Table 2 for the exact values) in order to create more general conclusions.…”

Section: Deeper Analysis Of the Examined Heat Pumpmentioning

confidence: 99%

“…They performed experimental work and they found similar performance with both configurations and also they stated that the system had worked about two months without problems after the use of R152a. In another work, Yang et al [18] found that the use of R152a in a cascade system with CO 2 is more efficient than the use of R134a/CO 2 and R124/CO 2 cascade systems.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Investigation of the Environmentally-Friendly Refrigerant R152a for Air Conditioning Purposes

Bellos

Tzivanidis

2018

Applied Sciences

View full text Add to dashboard Cite

Heat pumps are efficient and well-established technologies for providing the proper cooling load in the building sector. The objective of this work is the parametric investigation of a heat pump operating with the promising refrigerant R152a for different operating conditions. More specifically, the heat pump is studied for different ambient temperatures, different indoor temperatures and various compressor rotational speeds. The cooling capacity and the coefficient of performance (COP) are the most important parameters which calculated in every scenario. A detailed model is developed in Engineering Equations Solver (EES) and it is validated with literature data. According to the final results, the system can operate in nominal conditions with 5 kW cooling capacity and a COP equal to 6.46. It is found that the COP can be ranged from 4 to 12 and the cooling capacity, while the cooling capacity can reach up to 9 kW. Moreover, a regression equation about the performance of the system is suggested. The obtained results indicate that the use of the R152a leads to high performance and so it can be an environmentally friendly choice for the cooling systems.

show abstract

Section: Deeper Analysis Of the Examined Heat Pumpmentioning

confidence: 99%

Section: Deeper Analysis Of the Examined Heat Pumpmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Investigation of the Environmentally-Friendly Refrigerant R152a for Air Conditioning Purposes

Bellos

Tzivanidis

2018

Applied Sciences

View full text Add to dashboard Cite

show abstract

“…Furthermore, a potential configuration should be compared with others to evaluate its performance. Although amounts of researchers have proposed heat pump systems with large temperature lift, most of them mainly focused on a single system and few researchers made comparisons between them . Arpagaus et al conducted a detailed comparison on multitemperature heat pumps, where all of the compared cycles had two heat sources and one heat sink.…”

Section: Introductionmentioning

confidence: 99%

“…Although amounts of researchers have proposed heat pump systems with large temperature lift, most of them mainly focused on a single system and few researchers made comparisons between them. 11,[16][17][18][19][20] Arpagaus et al 11 conducted a detailed comparison on multitemperature heat pumps, where all of the compared cycles had two heat sources and one heat sink. They concluded from the comparison that multistage cycles had the best efficiency and the cascade cycles performed slightly worse than multistage cycles.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic analysis of novel heat pump cycles for drying process with large temperature lift

2019

View full text Add to dashboard Cite

Summary Heat pump–assisted drying has been recognized a prospective technology to meet the requirement of energy saving. However, large temperature lift will be resulted by the single‐stage heat pump cycle during the high‐temperature drying, especially operating with low ambient temperature for open‐loop drying, which leads to insufficient heat output, high compression ratio, and low coefficient of performance (COP). Two heat pump cycles, namely, multitemperature cascade cycle and combined single‐stage cycle, are proposed to address the above problems in the drying process with large temperature lift in this paper. The effects of varying operation parameters on the heat pump cycles are analyzed to optimize the cycle performance. Afterwards, the above two cycles as well as a conventional cascade cycle, a two‐stage compression cycle, and a single‐stage compression cycle are compared with each other in terms of cycle performance and drying performance under specified drying conditions. It is indicated by the results that the COPs of the multitemperature cascade cycle and combined single‐stage cycle are about 95% and 88% higher than that of the single‐stage compression cycle, respectively. As for the two cascade cycles (ie, conventional cascade cycle and multitemperature cascade cycle), 49% more water evaporation with the same power input can be resulted by the added condenser and evaporator. Among the five analyzed cycles, the multitemperature cascade cycle is the most promising to be used in the retrofitting of the drying equipment with large temperature lift.

show abstract

Thermodynamic and thermoeconomic analyses of an ejector/booster enhanced heat pump system with zeotropic mixture

2020

View full text Add to dashboard Cite

Summary In the current investigation, a novel ejector‐enhanced heat pump system was presented and comprehensively evaluated using zeotropic mixtures. In the suggested plant, a booster was added to the conventional ejector‐enhanced system to expand its performance. Moreover, the suggested plant was modeled in a way to operate zeotropic mixtures, in order to maximize the productivity of the system. The plant was investigated with regard to energy, exergy, and thermoeconomic analyses to have a deep insight of the performance characteristics, that is, exergy efficiency, COP, and unit price of the product. To this end, a parametric evaluation was conducted to predict the performance characteristics of the plant by changing the value of different input variables. The results of exergy analysis indicated that the maximum exergy annihilation (7.784 kW) was associated with the ejector. The proposed system was also compared with a conventional system, and the findings unfolded that the COP of the proposed system surpassed the conventional system by up to 25%. Moreover, the outcomes of thermoeconomic analysis showed that the unit product cost of the proposed system is 133.596 $/GJ. The outcomes further demonstrated that the highest performance of the plant was concluded using R‐600/R‐143a mixture fluid with R‐600 mass fraction of 0.45. The sensitivity evaluation further indicated that, by enhancing the condenser temperature, exergetic efficiency and heating load increased while COP and unit cost of product decreased. Moreover, there was an optimum local point, in terms of exergetic efficiency (29.5%), when the booster pressure ratio is about 1.4. In addition, at the ejector pressure lift of 1.15, the exergetic efficiency was maximized locally. The heating load of the system, however, increased continually with increasing pressure lift. The proposed system showed a decent functionality with respect to thermodynamic and thermoeconomic criteria.

show abstract

Theoretical study of a high-temperature heat pump system composed of a CO 2 transcritical heat pump cycle and a R152a subcritical heat pump cycle

Cited by 44 publications

References 30 publications

Investigation of the Environmentally-Friendly Refrigerant R152a for Air Conditioning Purposes

Investigation of the Environmentally-Friendly Refrigerant R152a for Air Conditioning Purposes

Thermodynamic analysis of novel heat pump cycles for drying process with large temperature lift

Thermodynamic and thermoeconomic analyses of an ejector/booster enhanced heat pump system with zeotropic mixture

Contact Info

Product

Resources

About