Person:
SAKA, KENAN

Profile Picture

Email Address

Birth Date

Research Projects

Organizational Units

OrgUnit Logo
Organizational Unit

Job Title

Last Name

SAKA

First Name

KENAN

Name

Filters

2019 - 20202
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Publication
    Performance assessment and solution procedure for series flow double-effect absorption refrigeration systems under critical operating constraints
    (Springer Heidelberg, 2019-06-01) Yılmaz, İbrahim Halil; Kaska, Önder; Saka, Kenan; SAKA, KENAN; Kaynaklı, Ömer; KAYNAKLI, ÖMER; 0000-0001-7840-9162; 0000-0002-2296-894X; AAH-5303-2021; AAX-2458-2020
    In this study, the effects of critical operational constraints on the operational domain of a double-effect lithium bromide/water absorption refrigeration system and its performance were investigated. These constraints were determined as the equivalence state of concentrations, the thermal unbalance between the system components of high-pressure condenser and low-pressure generator, freezing and crystallization risk of lithium bromide/water solution. For the system analysis, a simulation program was developed, and its detailed solution procedure was presented. The program outputs were initially validated with the literature. Subsequently, parametric studies were conducted for broad ranges of the component temperatures. The results demonstrate that the considered constraints were essential for acceptable design and the operational control of double-effect absorption refrigeration systems. The simulations will help to figure out under which operating conditions a double-effect absorption refrigeration system functions effectively and what kind of control strategies are essentially required to increase the coefficient of performance. Based on the operation scenario of fixed high-pressure generator temperature, the proposed system can enhance the coefficient of performance up to 31% and 84% as compared to its counterparts which function under the variable high-pressure generator temperature and the pinch point temperature difference (5K between the high-pressure condenser and the low-pressure generator), respectively.
  • No Thumbnail Available
    Publication
    Analysis and modeling of a membrane electrode assembly in a proton exchange membrane fuel cell
    (Amer Inst Physics, 2020-07-01) Orhan, Mehmet F.; Kahraman, Huseyin; Saka, Kenan; SAKA, KENAN; Bursa Uludağ Üniversitesi/Yenişehir İbrahim Orhan Meslek Yüksekokulu.; 0000-0002-2296-894X; AAH-5303-2021
    In this study, a membrane electrode assembly of a proton exchange membrane fuel cell is modeled. Using the analytical model, a computational analysis has been conducted along with an extensive parametric study. Variation of ohmic losses, water content, and voltage drops from anode to cathode side of the membrane electrode assembly with many design/operation parameters such as thickness, temperature, pressure, and local/total humidity and conductivity, diffusivity, and resistivity have been evaluated at various current densities. Also, effect of molar concentration of hydrogen on hydrogen diffusive flux due to pressure change between the anode and cathode at different membrane thicknesses has been presented. Furthermore, variation of water uptake and concentration with the ratio of water and hydrogen fluxes, the current density, and membrane dry density have been studied along with their interrelation. It is observed that as the membrane thickness increases, its resistivity increases as well, causing higher ohmic losses. On the other hand, the water content increases with the thickness until a maximum point and then starts to decrease. Therefore, the membrane thickness should be optimized carefully to have desirable humidity levels with minimum crossover and losses.