Analysis of temperature glide matching of heat pumps with zeotropic working fluid mixtures for different temperature glides

Zühlsdorf, Benjamin; Jensen, Jonas Kjær; Cignitti, Stefano; Madsen, Claus; Elmegaard, Brian

doi:10.1016/j.energy.2018.04.048

Cited by 95 publications

(36 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In refrigeration systems and heat pumps the main benefits of working fluid mixtures lie in the expansion of the availability of working fluids for system optimization, the compensation of undesirable properties of one of the components (e.g. flammability, global warming potential), as well as on the performance increase due to the improved temperature matching between the fluids exchanging heat [3]. In organic Rankine cycle power systems, the temperature glide represents the main advantage of their use, as it contributes to reduce irreversibilities during the phase change, resulting in better thermodynamic performance.…”

Section: Introductionmentioning

confidence: 99%

General heat transfer correlations for flow boiling of zeotropic mixtures in horizontal plain tubes

Zhang

Mondéjar

Haglind

2019

Applied Thermal Engineering

View full text Add to dashboard Cite

 Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

show abstract

Section: Introductionmentioning

confidence: 99%

General heat transfer correlations for flow boiling of zeotropic mixtures in horizontal plain tubes

Zhang

Mondéjar

Haglind

2019

Applied Thermal Engineering

View full text Add to dashboard Cite

show abstract

“…The results showed that employing an inner heat exchanger expands the performance of the plant by 5.5% and heating capacity by 5% when the mentioned mixture refrigerant was employed. Zühlsdorf et al 39 analyzed the temperature glide matching of heat pumps using zeotropic refrigerant by considering various temperature glides, and Fan et al 40 determined the functionality of the heat pumps with zeotropic mixtures specifically for district cold region. Mixture of R‐32/R‐290 was concluded to have the best performance among other mixtures.…”

Section: Introductionmentioning

confidence: 99%

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

“…The development status of HTHPs configurations is still mostly limited to theoretical analysis, such as those performed by Cao et al, and Mateu-Royo et al [11,12], which considered an external heat exchanger in one and two stages, or those performed by Mota-Babiloni et al and Yang et al [13,14], which considered HTHP cascades. Moreover, an intensive theoretical study was performed on the energy performance benefits provided by the use of zeotropic mixtures [15,16].…”

Section: Introductionmentioning

confidence: 99%

Experimental exergy and energy analysis of a novel high-temperature heat pump with scroll compressor for waste heat recovery

et al. 2019

View full text Add to dashboard Cite

The industrial sector demands novel sustainable energy systems to advance in its decarbonisation and meet the targets of the Paris Agreement for the climate change mitigation. High-Temperature Heat Pumps (HTHPs) are being investigated as a feasible energy conversion technology alternative to traditional fossil fuel boilers. This paper presents the first experimental results of an HTHP prototype equipped with a modified scroll compressor and internal heat exchanger (IHX). The elements of the main and secondary circuits are presented, as well as the test methodology and heat balances are exposed. The tests have been performed using HFC-245fa at heat source temperatures between 60 and 80 °C, and heat sink temperatures between 90 and 140 °C. The heating capacity and coefficient of performance (COP) varied between 10.9 and 17.5 kW and between 2.23 and 3.41, respectively. An exergetic analysis indicated that the expansion valve was the component with the worst second law efficiency and the compressor presented the highest potential improvement over the other cycle components. A computational analysis of low global warming potential (GWP) refrigerant alternatives was carried out, which confirmed the benefits of using an internal heat exchanger (IHX) and the good performances of the low-GWP refrigerants: HCFO-1224yd(Z), HCFO-1233zd(E), and HFO-1336mzz(Z). Finally, we proved that the proposed system can save up to 57% of the equivalent CO2 emissions of a natural gas boiler. This paper provides a reference for the high-temperature heat pump recovery of the lowgrade waste heat from industrial energy processes.

show abstract

Analysis of temperature glide matching of heat pumps with zeotropic working fluid mixtures for different temperature glides

Cited by 95 publications

References 21 publications

General heat transfer correlations for flow boiling of zeotropic mixtures in horizontal plain tubes

General heat transfer correlations for flow boiling of zeotropic mixtures in horizontal plain tubes

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

Experimental exergy and energy analysis of a novel high-temperature heat pump with scroll compressor for waste heat recovery

Contact Info

Product

Resources

About