Sürdürülebilir Kalkınma Amaçları
Yazarlar
Yayınlar
- Derleme MakaleAçık Erişim2019Scopus SJRQ2Thermoelectric Coolers (TECs): From Theory to Practice
Guclu, Tamer; Cuce, Erdem
Thermoelectric coolers (TECs) are solid state units, which provide reliable energy conversion with no noise or vibration. They are also lightweight and do not include any moving parts. The current coefficient of performance (COP) range of TECs has shown a trend of improvement, and TECs have a wide range of usage areas. Within the scope of this research, TECs are comprehensively evaluated in terms of several aspects such as type, material, design, modelling, thermal performance, potential applications, economic and environmental issues. It can be achieved through the results that the COP of TECs is highly dependent on the temperature difference between hot and cold side (ΔT), and maximum COP is obtained when ΔT is close to zero. It is also observed that COP can be enhanced by more than 55% when the hot side is thermally regulated by phase change materials (PCMs) or integrated with a water cooling unit.
AtıfScopus69WoS61OpenAlex76
İncele - Derleme MakaleAçık Erişim2018Scopus SJRQ1Concentrating photovoltaic thermal (CPVT) collectors and systems: Theory, performance assessment and applications
Daneshazarian, Reza; Cuce, Erdem; Cuce, Pinar Mert; Sher, Farooq
Concentrating photovoltaic thermal (CPVT) collectors and systems are very popular in both domestic and industrial solar energy applications. CPVT collectors provides incomparably greater thermal and electrical outputs compared to stand alone PV or hybrid PVT systems as incoming solar energy is maximised inside the unit via energy-efficient concentrators. Within the scope of this paper, a comprehensive review on CPVT collectors and systems is proposed. For an easier assessment of the findings through state-of-the-art analyses on CPVT collectors, the review is presented in a thematic way. Historical overview of the technology is followed by the detailed description of a CPVT collector with main system elements and thermodynamic performance definitions. The review also covers thermal and electrical performance analysis of CPVT collectors using water or air as working fluid, analytical, numerical, simulation and experimental works for performance evaluation of different design configurations of CPVT systems and qualitative analysis of electrical and thermal energy generation. The impacts of concentrator type and concentration ratio on system efficiency, operating temperature and coefficient of performance (COP) are analysed in detail. It is observed from the findings that CPVT collectors are promising devices in market, and they have a good potential to be competitive with conventional power generation systems in the near future.
AtıfScopus193WoS174OpenAlex214İncele - MakaleYalnız künye2013Scopus SJRQ1An experimental exergetic comparison of four different heat pump systems working at same conditions: As air to air, air to water, water to water and water to air
Çakir, Uǧur; Çomakli, Kemal; Çomakli, Ömer; Karsli, Süleyman
In this study, we designed a multifunctional heat pump system using just one scroll compressor and which can be run in four different modes, namely air to air, air to water, water to water and water to air, in order to make an experimental energetic and exergetic performance comparison. Experimental system consists of two condensers and two evaporators and uses R22 as working fluid. One of the evaporators and condensers uses water and the others use air as heat source/sink. Heating capacities of four heat pump types are equal to each other. It is realized by adjusting the mass flow rate and temperature level of external fluid of condenser. Results show that the heat pump unit which has the maximum COP (coefficient of performance) value is water to air type with 3.94 and followed by water to water type with 3.73, air to air type with 3.54 and air to water type with 3.40. Ranking of four heat pump types with respect to their mean exergy efficiency is as follows; water to air type with 30.23%, air to air type with 30.22%, air to water type with 24.77% and water to water type with 24.01%. Exergy destruction rates of the systems were investigated in this study and the results revealed that the heat pump type which has the maximum exergy destruction is air to air type with 2.93kW. The second highest one is air to water type with 2.84kW. The third highest one is water to air type with 2.64kW and last one is water to water type with 2.55kW. It is understood that the temperature of the evaporator external fluid affects the exergetic efficiency of the system more than the mass flow rate. In contrast to the previous, the dominant parameter which has more important effect on the exergy destruction of the heat pump unit is the mass flow rate of evaporator external fluid.
AtıfScopus55WoS46İncele