Optimal thermodynamic parameters of two-phase ejector refrigeration system for buses

Ünal, Şaban; Erdinç, Mehmet Tahir; Kutlu, Çağrı

doi:10.1016/j.applthermaleng.2017.06.115

Cited by 24 publications

(6 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to calculate the heat transfer rate, fin efficiency should be determined. Unal et al (Unal, Erdinc, and Kutlu 2017) used fin efficiency as 0.73 in their study for air cooling system. However, the efficiency depends on the dimensions and configuration of the heat exchanger; thus, it needs to be recalculated for each geometry of fin.…”

Section: Design Of the Finned Tube Heat Exchanger For The Fridge Cabinetmentioning

confidence: 99%

Development and testing of a PCM enhanced domestic refrigerator with use of miniature DC compressor for weak/off grid locations

Riffat

Kutlu

Tapia-Brito

et al. 2021

International Journal of Green Energy

View full text Add to dashboard Cite

This paper presents the development of a sustainable and affordable domestic refrigerator for rural areas where grid setting is weak or non-existent. The refrigerator uses a miniature refrigeration unit based on a micro direct current (DC) compressor, which can adjust its speed according to photovoltaic output variation with solar radiation intensity, in order to maximize cooling production. The experimental investigation aims to define the cooling capacity management of the refrigerator through the use of phase change materials (PCMs). PCM packs in the fridge are charged during the period of high solar radiation and, afterward, melting of PCM releases cooling to maintain a cold temperature for extra hours when solar radiation is low or not available. The paper presents the design and construction of an experimental refrigerator with a miniature refrigeration unit of a finned tube heat exchanger for the fridge cabinet; PCM selection and, particularly, the effect of heat transfer enhancement at the condenser are discussed. Lab-scale tests were carried in the UK and field tests were carried out in Ghana in a collaboration project. In lab-scale tests, it is found that a condenser modification can decrease the transient power consumption by up to 26%. In contrast, the field-testing results show that the daily power consumption can be reduced only from 0.9 to 0.84 kWh. Additionally, field testing results show that the cabinet temperature of the PCM-enhanced refrigerator rose from 7°C to 11°C after a period of 5 hr power outage.

show abstract

Section: Design Of the Finned Tube Heat Exchanger For The Fridge Cabinetmentioning

confidence: 99%

Development and testing of a PCM enhanced domestic refrigerator with use of miniature DC compressor for weak/off grid locations

Riffat

Kutlu

Tapia-Brito

et al. 2021

International Journal of Green Energy

View full text Add to dashboard Cite

show abstract

“…To find the effectiveness of the heat exchangers, the effectiveness-NTU method was implemented in the analysis. Some equations are used [44], [45], [46] to find heat transfer coefficients for single and two phase states in the literature. This study uses Gnielinski equation where the fluids exist in a single state (liquid water, pure liquid and pure vapor R245fa), as given in Eqs.…”

Section: Heat Exchanger Modelling and Control Strategymentioning

confidence: 99%

Off-design performance modelling of a solar organic Rankine cycle integrated with pressurized hot water storage unit for community level application

Kutlu

et al. 2018

Energy Conversion and Management

View full text Add to dashboard Cite

Solar organic Rankine cycle (ORC) has advantages over common PV systems in view of the flexible operation even if solar radiation is unavailable. However, at present the dynamic performance of solar ORC with respect to the off-design behaviour of storage unit, expander, pump and heat exchanger is rarely reported. This paper investigates a medium-temperature solar ORC system characterized by evacuated flat-plate collectors and pressurised water storage unit. The main aim of the study is to investigate the performance of the system with consideration of transient behaviour of the thermal storage unit which results in off-design operation of other components. The other aim is adjusting the power output according to electricity demand throughout a day. The heat storage unit is analysed using one-dimensional temperature distribution model. A transient simulation model is developed including pump and expander models. To meet the electrical demands of different periods, the mass flow rate of heat source is adjusted for controlling the evaporation temperature. Moreover, sliding pressure operation control strategy of the ORC is implemented to meet variable heat source temperature. A 550 m 2 solar collector area and a 4 meters diameter and 7 meters height pressurized water cylinder are used in simulation. Produced work is controlled and the results are matched with the demands. Produced work from the expander under the given conditions are 47.11 kWh in day time, 70.97 kWh in peak period and 31.59 kWh after midnight.

show abstract

“…The influence of condensation and evaporation is inspected. According to results, 55% and 4% of heat transfer surface area can be reduced for evaporator and condenser, respectively [4].…”

Section: Introductionmentioning

confidence: 99%

“…The influence of condensation and evaporation is inspected. According to results, 55% and 4% of heat transfer surface area can be reduced for evaporator and condenser, respectively [4]. Khaliq introduced a refrigeration system which is a combination of ejector expansion Joule-Thomson cooling cycle and ejector-absorption refrigeration cycle powered by waste heat [5].…”

Section: Introductionmentioning

confidence: 99%

Comparative Analysis of Ejector Refrigeration System Powered with Engine Exhaust Heat using R134a and R245fa

Yılmaz¹,

Aktaş²

2019

European Mechanical Science

View full text Add to dashboard Cite

An ejector refrigeration (ER) system using exhaust waste heat of a heavy vehicle engine is investigated. A program is developed using engineering equation solver software and it is used to make the calculations of the system. The system is taking all the efficiencies of system's components into account. Refrigerants R134a and R245fa are used for the comparative simulation of the system. The pressure at the exit of the pump is varied from 6 to 14 MPa and 3 to 10 MPa for R134a and R245fa, respectively. It can be concluded that COP (coefficient of performance) of the system gradually increases with the increase in pump exit pressure. Results show that, the performance of the system would be higher if R245fa is preferred rather than R134a with the given operating conditions.

show abstract

Optimal thermodynamic parameters of two-phase ejector refrigeration system for buses

Cited by 24 publications

References 19 publications

Development and testing of a PCM enhanced domestic refrigerator with use of miniature DC compressor for weak/off grid locations

Development and testing of a PCM enhanced domestic refrigerator with use of miniature DC compressor for weak/off grid locations

Off-design performance modelling of a solar organic Rankine cycle integrated with pressurized hot water storage unit for community level application

Comparative Analysis of Ejector Refrigeration System Powered with Engine Exhaust Heat using R134a and R245fa

Contact Info

Product

Resources

About