Browsing by Author "Baker, Derek K."

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Citation - WoS: 16
Citation - Scopus: 19
Cop Trends for Ideal Thermal Wave Adsorption Cooling Cycles With Enhancements
(Elsevier Sci Ltd, 2012) Taylan, Onur; Baker, Derek K.; Kaftanoglu, Bilgin; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
Models are presented for ideal thermal wave adsorption cooling cycles without mass recovery, with adiabatic mass recovery and with isothermal mass recovery. Coefficient of performance (COP) values obtained from simulations are compared with the results of a reversible cycle and previously developed models for a simple cycle and heat recovery cycle with two spatially isothermal beds (2SIB). The effects of maximum and minimum bed temperatures, bed's dead mass, and condensation and evaporation temperatures on COP were investigated. The thermal wave cycle has significantly higher COP's than the simple and 2SIB cycles. For the conditions investigated, adding mass recovery to the thermal wave cycle does not affect its COP significantly. The COP of the thermal wave cycle increases with increasing maximum bed and evaporation temperatures and decreasing minimum bed and condensation temperatures. Unlike for the simple and 2SIB cycles, variations in the bed's dead mass have minimal impact on COP. (C) 2010 Elsevier Ltd and IIR. All rights reserved.
Citation - WoS: 5
Measurement of Solar Radiation in Ankara, Turkey
(Turkish Soc thermal Sciences Technology, 2013) Caglar, Ahmet; Yamali, Cemil; Baker, Derek K.; Kaftanoglu, Bilgin; Basic Sciences; Manufacturing Engineering; 06. School Of Engineering; 08. Medical School; 01. Atılım University
The solar energy potential of Ankara, Turkey, (39.89 degrees N, 32.78 degrees E) has been investigated using the measurements of global and beam radiation over the period May 2008 to May 2009. Surface air temperature was also measured and variation in clearness index evaluated over this period. Global and beam radiations have been analyzed using hourly, daily and monthly averages obtained from 1-minute averages of recorded data. Results show that annual average daily global and beam radiations were 17.04 and 15.72 MJ/m(2)/day, respectively, for this period. The results are compared with the data available for several other cities in Turkey. The study shows that Ankara has a large solar potential. The consistency of these data with that from the State Meteorological Service (SMS) weather station in Ankara was analyzed. Significant differences between these 2 stations were found and are attributed to measurement error at the SMS station. New radiation-measurement stations should be established to create a better national radiation database for Turkey.
Normalized thermodynamic model for intermittent energy systems and application to solar-powered adsorption cooling systems
(2011) Taylan, Onur; Baker, Derek K.; Kaftanoğlu, Bilgin; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
Genel kesildi enerji sistemlerinin tasanm ve işletmedeki kilit parametreleri değişirken ara ve talep eşzamanlılığını nicelleştirmek ve açıklığa kavuşturmak için bir normalleştirilmiş model geliştirildi. Bu yeni model, güneş ısısı ile beslenen, iç ısı değiştiricin ve iç ısı değiştiricisiz adsorpsiyonlu sistemin mevsimsel değişimlerinin benzetişimin de güneş ısısıyla sağlanan soğutmanın ve soğutma talebinin eşzamanlılığını mevsimsel güneşle besleme payı faktörü ve kayıp faktörü yardımıyla İncelemek için uygulandı. İlaveten sistemin bir grup parametrelerinin değişimiyle temel başarımmdaki değişim eğilimleri incelendi. İnceleme şartlanndaki sonuçlar şunları içermektedir: Depo sığası (kapasitesi) artınca güneş payı faktörü artmakta ve kayıp faktörü azalmaktadır, ve maksimum yatak sıcaklığı artınca her iki faktör de küçülmektedir. Vakum tüplü toplaç için gerekli alan düz levha toplaç için gerekli alandan daha azdır, bunun yam sıra adsorbsiyon için gerekli malzeme kütlesi toplacın ve adsorbsiyon çevriminin tipinden bağımsızdır. Benzetişim sonuçları çalışma şartlarının ve değişik tasanm parametrelerinin sistem C.O.P si (başarım katsayısı) üzerine etkilerini de göstermektedir.
Citation - WoS: 1
Citation - Scopus: 1
Normalized Thermodynamic Model for Intermittent Energy Systems and Application To Solar-Powered Adsorption Cooling Systems
(int Center Applied thermodynamics, 2011) Taylan, Onur; Baker, Derek K.; Kaftanoglu, Bilgin; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
A new normalized model is developed to quantify and explore trends in coincidence of supply and demand in generic intermittent energy systems as key design and operating parameters are varied. This novel model is applied to seasonal-transient simulations for a solar-thermal powered adsorption system with and without heat recovery to investigate the coincidence between the solar-supplied cooling power and cooling load in terms of seasonal solar and loss fractions. Additionally, the system's basic performance trends are investigated as a number of parameters are varied. Results for the conditions explored include the following. The solar fraction increases and the loss fraction decreases with increases in storage capacity, and both fractions decrease with increases in maximum bed temperature. The required evacuated tube collector area is smaller than the flat plate collector area while the required mass of adsorbent is independent of collector and adsorption cycle types. Simulation results also show the effects of operating conditions and several design parameters on the system's COP.