Profile URL: https://hdl.handle.net/20.500.13091/11926
Job Title:Doç. Dr.
Email Address:nbilir@ktun.edu.tr
Main Affiliation:02.10. Department of Mechanical Engineering
Status: Current Staff
ORCID:
0000-0001-8410-0268
0000-0001-8410-0268Scopus ID:
26634774600
26634774600YÖK Akademik: 068445A940C46369
Google Scholar:
zMW6SmsAAAAJ
zMW6SmsAAAAJWeb of Science ID:
ABF-9623-2021
ABF-9623-2021Name Variants:
Bilir Sag, N. Bilir Sağ, N.
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Master Thesis Trilateral Çevrim ve Organik Rankine Çevrimini Kullanan Birleşik Güç Sisteminin Termodinamik Analizi(Konya Teknik Üniversitesi, 2020) Özçelik, Mehmet; Bilir Sağ, NagihanYenilenebilir enerji kaynaklarının ısı enerjisini veya atık ısı enerjisini kullanarak güç üretmek için birçok yöntem vardır. Bu yöntemlerden en yaygın kullanılanlardan biri de Organik Rankine çevrimidir. Organik Rankine çevrimi ile birlikte Trilateral çevrim / Organik Rankine çevrimi kullanarak yenilenebilir veya atık ısı enerjisinden daha fazla yararlanmak amaçlanmıştır. Bu amaçla, Reküperatörlü Trilateral çevrim - Organik Rankine çevrim, Trilateral çevrim - Organik Rankine çevrim ve Organik Rankine çevrim - Organik Rankine çevrim birleşik güç sistemlerinin yapıları incelenerek Engineering Equations Solition (EES) programı yardımı ile termodinamik analizleri yapıldı. Birleşik güç sistemler için jeotermal kaynak ve düşük sıcaklık evaporatörünün farklı sıcaklık değerlerinde sistem performansını maksimum yapan en iyi akışkan çiftleri belirlendi ve bu belirlenen akışkan çiftleri kullanılarak her üç sistem için de elde edilen sonuçlar karşılaştırıldı. Araştırılan çalışma şartları için hangi sistemin performansının daha iyi olduğu belirlendi. Jeotermal kaynak ve düşük sıcaklık evaporatörünün farklı sıcaklık değerlerinde üç birleşik güç çevrimin enerji analizi yapıldı. Çevrimlerde kullanılan çalışma akışkanları ile sistem çalışma şartlarına bağlı olarak en yüksek ısıl verim ve güç çıktısı değerlerinin hangi birleşik güç sistemde elde edileceği araştırıldı. Araştırma sonuçlarına göre, her bir çalışma şartı için ısıl verimi ve/veya sistemden elde edilen net gücü maksimum yapan akışkan çiftleri olduğu tespit edildi. Jeotermal kaynağının veya düşük sıcaklık çevrim evaporatörünün sıcaklığı arttıkça araştırılan birleşik güç sisteminin de ısıl veriminin arttığı bulundu. Jeotermal kaynağın her bir sıcaklığı için birleşik güç sistemin net gücünü maksimum yapan düşük sıcaklık çevrim evaporatör sıcaklığının olduğu tespit edildi. Çalışma şartlarına bağlı olarak ORÇ-ORÇ'nin net güç çıktısı araştırılan diğer sistemlerden elde edilen ile hemen hemen aynı veya % 23,5'e kadar daha yüksek olduğu belirlendi bu yüzden, araştırılan çalışma şartları için Organik Rankine çevrim - Organik Rankine çevrim birleşik güç sistemin kullanılması gerektiği sonucuna varıldı.Article Optimization of Co2 Booster Refrigeration Cycle With Flooded Evaporators and Parallel Compressor by Using the Bees Algorithm(Pamukkale Univ, 2024) Isik, Metehan; Sag, Nagihan Bilir.; Kalyoncu, MeteEnergy supply is one of the most significant issues in modern society. So, energy saving becomes important in systems used frequently in daily life. Due to these energy saving concerns, there are numerous studies in literature to make supermarket refrigeration systems consume less energy. Among these studies, CO2 booster refrigeration system with flooded evaporators and parallel compressor (BFP) seems as an energy-saving and nature-friendly choice. In this study, BFP was selected as the system of concern and the Bees Algorithm optimization was applied to get minimum power consumption (maximum COP). Gas cooler pressure (P-gc), intermediate pressure(P-int), and medium temperature (MT) level evaporator outlet quality(x(14)) were chosen as optimization parameters. According to the optimization results, the Bees Algorithm converged well, and these three parameters were found worthy to optimize as they brought significant energy saving in total (up to 8.7% in comparison with constant intermediate pressure and MT evaporator outlet quality). As a result of this analysis, the optimal P-gc values were found to be between 7600 kPa and 12000 kPa at ambient temperatures ranging from 28 to 46 degrees C. The optimal Pint values were found to be around 3500 kPa below ambient temperature of 14 degrees C and around 4500 kPa above this temperature. The optimal values for x(14) ranged between 0.62 and 0.69. Additionally, annual energy consumption (AEC) and total equivalent emission (TEE) for 15 years were calculated for four different climate types. The highest AEC and TEE were obtained at tropical climate with 728.56 MWh and over 10000 tons, respectively. The lowest AEC and TEE were found at continental conditions as 380.01 MWh and almost 6000 tons of emission.Article Citation - WoS: 1Citation - Scopus: 1Performance Analysis of a Novel Directly Combined Organic Rankine Cycle and Dual-Evaporator Vapor Compression Refrigeration Cycle(MDPI, 2025-07-31) Bilir Sag, Nagihan; Isik, MetehanCombining Organic Rankine Cycles (ORC) with cooling cycles offers a promising approach to achieving greater outputs within a single system. In this study, a novel directly combined ORC-VCC system has been designed to not only meet the cooling demand using a geothermal heat source but also generate power. The proposed novel ORC-VCC system has been analyzed for its energetic performance using four selected fluids: R290, R600a, R601, and R1234ze(E). Parametric analysis has been conducted to investigate the effects of parameters of heat source temperature, heat source mass flow rate, cooling capacities, condenser temperature, ORC evaporator temperature, pinch point temperature difference and isentropic efficiencies on net power production. Among the working fluids, R290 has provided the highest net power production under all conditions in which it was available to operate. Additionally, the results have been analyzed concerning a reference cycle for comparative evaluation. The proposed novel cycle has outperformed the reference cycle in all investigated cases in terms of net power production such as demonstrating an improvement of approximately from 8.7% to 57.8% in geothermal heat source temperature investigations. Similar improvements have been observed over the reference cycle at lower heat source mass flow rates, where net power increases by up to 50.8%.Article Comparative Performance Analysis of Combined Power Systems Trilateral Cycle-Organic Rankine Cycle (tlc-Orc) and Organic Rankine Cycle Organic Rankine Cycle (orc-Orc)(Konya Technical University, 2021-09-01) Bilir Sağ, Nagihan; Özçelik, Mehmet; Sag, Nagıhan BılırOne of the most widely used to generate power using heat energy or waste heat energy from renewable energy sources is the Organic Rankine cycle. The Trilateral Cycle differs from the Organic Rankine cycle in that it uses an expander instead of a turbine element. In this study, the structures of Trilateral cycle - Organic Rankine cycle and Organic Rankine cycle - Organic Rankine cycle combined power systems were examined and thermodynamic analyzes were made with the help of Engineering Equation Solver (EES) program. For each combined power system, the fluid pairs that maximize the system performance at different temperatures of the geothermal source and sub-cycle evaporator were determined and the results of the combined power systems using these determined fluid pairs were compared. According to the results of the research, it was determined that there are pairs of fluids that maximize the thermal efficiency and / or the net power obtained from the system for each operating condition. It was determined that at temperatures of 100-280 oC of the geothermal resource, the combined power system was evaporating hot, which maximized the net power. Depending on the working conditions, it was determined that the net power output of ORC-ORC was up to until 23.5 % higher than TLC-ORC.Article A Novel Geothermal-Powered Combined ORC-Dual Evaporator Refrigeration System for Power, Cooling, and Heating: Exergetic, Exergoeconomic and Exergoenvironmental (3E) Analysis(Elsevier - Division Reed Elsevier India Pvt Ltd, 2026-04-01) Isik, Metehan; Sag, Nagihan Bilir; Bilir Sağ, NagihanThe design of energy-efficient systems has become a central focus in recent years due to the growing demand for sustainable and environmentally friendly technologies. Efforts toward developing approaches that enhance energy production while simultaneously reducing consumption is increasing. Accordingly, utilizing geothermal heat sources for multiple purposes has gained increasing attention due to their potential to improve resource utilization and overall efficiency. However, the effective utilization of geothermal resources is still limited by their generally low-to-medium temperature levels, restricted efficiency, and the fact that most systems serve only one purpose. These issues lead to low overall resource utilization and reduced economic viability. Therefore, this study investigates a novel geothermally-driven directly combined Organic Rankine Cycle-Vapor Compression Cycle (ORC-VCC) system that simultaneously delivers power, cooling, and heating. The integrated configuration increases the fraction of geothermal heat converted into useful outputs and improves the thermodynamic and economic performance of the resource. Additionally, exergetic, economic, and environmental evaluations are essential for ensuring the sustainability of energy systems. In this study, the novel cycle has been comprehensively investigated in terms of exergy, exergoeconomic, and exergoenvironmental performance for various operating conditions. The results obtained have been compared with a reference cycle under same operating conditions. The novel cycle provides higher exergy efficiency and better exergoeconomic results under all the conditions investigated. For instance, at the geothermal heat source temperature of 110 degrees C and mass flow rate of 5 kg/s, the novel cycle provides 47.1%, 44.2% and 6.5% improvement over the reference cycle in terms of exergy efficiency, total unit cost and total unit environmental impact of products, respectively. Also, more than 25% improvement at exergy efficiency over the reference cycle is obtained at 200 kW medium temperature evaporator cooling capacity by the novel cycle.Conference Object Investigation of the Combined Tlc-Orc and the Combined Orc-Orc Power Systems(2019) Özçelik, Mehmet; Bilir Sağ, NagihanOne of the best performances in waste heat and power generation systems is the organic Rankine cycle. The difference of the Organic Rankine Cycle from the basic Steam Rankine Cycle is the use of organic fluids as the working fluid. Power generation can be achieved from low temperature heat sources (80-90oC) with organic fluids. In this study, studies on dual loop combined power systems and system structures were investigated. As a result of the investigations, it was concluded that higher thermal efficiency and lower exergy destruction were obtained from combined Trilateral Cycle-Organic Rankine Cycle power system.Article CO2 akışkanlı yaş evaporatörlü paralel kompresörlü booster soğutma çevriminin güç tüketiminin arı algoritması ile optimizasyonu(2023) Kalyoncu, Mete; Işık, Metehan; Sağ, Nagihan BilirModern toplumdaki en önemli konulardan biri enerji tedariğidir. Bunedenle günlük hayatta sıklıkla kullanılan sistemlerde enerji tasarrufuönem kazanmaktadır. Bu enerji tasarrufu hedeflerine yöneliksüpermarket soğutma sistemlerinin daha az enerji tüketmesiniamaçlayan çok sayıda çalışma literatürde bulunmaktadır. Buçalışmalar arasında yaş evaporatörlü ve paralel kompresörlü CO2booster soğutma çevrimi (BFP) enerji tasarruflu ve doğa dostu bir seçimolarak ön plana çıkmaktadır. Bu çalışmada, BFP çevriminde minimumgüç tüketimini (maksimum COP) elde etmek için Arı Algoritmasıoptimizasyonu uygulanmıştır. Optimizasyon parametreleri olarak gazsoğutucu basıncı (𝑃𝑔𝑐), ara basınç (𝑃𝑖𝑛𝑡) ve orta sıcaklık (MT) seviyesievaporatörü çıkış kuruluk derecesi (𝑥14) seçilmiştir. Arı Algoritmasıoptimizasyon sonuçlarına göre bu üç parametre, toplamda önemliölçüde enerji tasarrufu sağlamaları sebebiyle (sabit ara basınç ve sabitMT evaporatör çıkış kuruluk derecesine kıyasla %8.7'ye kadar)optimize edilmeye değer bulunmuştur. Analiz sonucunda, optimum 𝑃𝑔𝑐değerlerinin 28 °C ila 46 °C arasındaki çevre sıcaklıklarında 7600 kPaile 12000 kPa arasında olduğu tespit edilmiştir. Optimum𝑃𝑖𝑛𝑡 değerlerinin 14 °C çevre sıcaklığının altında yaklaşık 3500 kPa vebu sıcaklığın üstünde yaklaşık 4500 kPa olduğu bulunmuştur. x14 içinoptimum değerler 0.62 ile 0.69 arasında elde edilmiştir. Ayrıca dörtfarklı iklim tipi için yıllık enerji tüketimi (AEC) ve 15 yıllık toplameşdeğer emisyon (TEE) hesaplanmıştır. En yüksek AEC ve TEE sırasıyla728.56 MWh ve 10000 tonun üzerinde değerlerle tropikal iklimde eldeedilmiştir. En düşük ise 380.01 MWh AEC ve yaklaşık 6000 ton TEE ilekarasal iklimde bulunmuştur.Article Citation - WoS: 5Citation - Scopus: 4Energetic, Economic, and Environmental Analysis of Co2 Booster Refrigeration Systems of Supermarket Application for Türkiye(Springer India, 2023-11-30) Işık, Metehan; Sag, Nagihan Bilir; Bilir Sag, NagihanRefrigeration systems account for nearly half of the electricity consumed by supermarkets. In order to save energy and reduce CO2 emissions, CO2 booster refrigeration systems have been developed. This paper discusses three of them due to their high energy efficiency, economic feasibility, and environmental friendliness for supermarkets of T & uuml;rkiye for the first time in the literature. These systems are the standard CO2 booster system (BRC), the CO2 booster refrigeration system with the flooded evaporators (BRC-FE), and the CO2 booster refrigeration system with the flooded evaporators and parallel compressor (BRC-FE-PAR). Power consumption values, coefficient of performance (COP) values, annual energy consumptions (AEC), installation and operating costs, and CO2 emissions of the systems are calculated and compared with the reference R404A refrigeration system (Reference System) under different climatic conditions. The highest COP values are obtained for BRC-FE-PAR under 30 degrees C ambient temperatures. Above this temperature, the Reference system has the highest COP. The BRC has the highest AEC, while the BRC-FE-PAR has the lowest among CO2 booster systems. The BRC-FE-PAR is the cycle with the highest saving (2.2%-19.4%) as compared to the Reference System in all cities considered. The investigated CO2 booster systems have lower emission values between 23.4% and 52.2% than the Reference System.Article Türkiye'deki Süpermarketler için Yaş Evaporatörlü ve Paralel Kompresörlü Co2 Booster Soğutma Çevrimlerinin Enerji ve Çevre Analizi(Turkish Soc Thermal Sciences Technology, 2024-06-03) Bilir Sağ, Nagihan; Işık, Metehan; Sag, Nagıhan BılırCO2 booster soğutma sistemleri yüksek enerji verimliliğine sahip olup çevre dostudur. Bu nedenle, bu çalışmada süpermarketler için CO2 akışkanlı yaş evaporatörlü ve paralel kompresörlü soğutma çevrimi (BFP), BFP’ye mekanik aşırı soğutma eklenen soğutma çevrimi (BFP-MSC) ve BFP’de buharlaşmalı soğutma kullanılan soğutma çevrimi (BFP-EVC) incelenmiştir. Bu sistemler analiz edilerek enerji ve çevre performansı açısından hangi sistemin daha iyi performans gösterdiği literatürde ilk kez Türkiye'deki süpermarketler için ortaya konulmuştur. Araştırma sonuçlara göre, BFP-MSC’nin aynı kuru termometre sıcaklıklarında BFP'ye göre %16.67'ye kadar daha yüksek soğutma performans katsayısına (COP) sahip olduğu belirlenmiştir. Bunun yanı sıra, her şehirde BFP-EVC, en düşük yıllık enerji tüketimine (AEC) sahiptir, onu BFP-MSC ve ardından BFP takip etmektedir. BFP-EVC'nin BFP'ye göre sağladığı yıllık tasarruf %10.81 ile %25.47 arasında değişmektedir. Ek olarak, BFP-EVC, yaş termometre sıcaklıklarına bağlı olarak analiz edildiği için, nem oranının düşük olduğu şehirlerde daha yüksek tasarruflar sağlamaktadır.Article Citation - WoS: 9Citation - Scopus: 9Thermodynamic, Environmental, and Exergoeconomic Analysis of Multi-Ejector Expansion Transcritical Co2 Supermarket Refrigeration Cycles in Different Climate Regions of Türkiye(Elsevier Sci Ltd, 2024) Çalışkan, Oğuz; Bilir Sağ, Nagihan; Ersoy, Kurşad; Sag, Nagihan Bilir; Ersoy, H. KursadRestrictions on high-GWP refrigerants have made the use of transcritical CO 2 refrigeration systems widespread. Using transcritical booster refrigeration cycle in warm climates is unsatisfactory due to its high energy consumption. This paper presents theoretical analysis and performance comparison of three different transcritical CO 2 supermarket refrigeration cycle configurations with ejector expansion in T & uuml;rkiye, which has different climatic regions. Bin-hour data were derived using hourly dry-bulb temperature values for provinces from 7 different regions in T & uuml;rkiye. The applicability of multi-ejectors to each modeled cycle was also investigated. Annual energy consumption and environmental impact reductions of up to 17% were obtained using ejector expansion cycle compared to booster cycle. Ejector expansion cycles achieved higher performance than booster cycle up to 46% in terms of exergy efficiency at investigated ambient temperatures. Unit product exergy costs of the ejector cycles were found up to 28% lower than booster cycle.
Research Topics
Domains
Physical Sciences
Fields
Engineering
Subfields
Mechanical Engineering
Specific Research Areas
Refrigeration and Air Conditioning Technologies
Advanced Thermodynamic Systems and Engines
Thermodynamic and Exergetic Analyses of Power and Cooling Systems
Heat Transfer and Optimization
Heat Transfer and Boiling Studies
Sustainable Development Goals
7AFFORDABLE AND CLEAN ENERGY
5
Research Products
13CLIMATE ACTION
2
Research Products
11SUSTAINABLE CITIES AND COMMUNITIES
2
Research Products
8DECENT WORK AND ECONOMIC GROWTH
2
Research Products
Documents
11
Citations
461
h-index
7
Documents
11
Citations
412
Publication Collaboration
| Affiliation Name | Count |
|---|---|
| Konya Technical University | 7 |
| Selçuk University | 5 |
| Yaşar University | 3 |
| Van Yüzüncü Yıl Üniversitesi | 1 |
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Data obtained from OpenAlex
| Journal | Count |
|---|---|
| Applied Sciences-Basel | 1 |
| DergiPark (Istanbul University) | 1 |
| Engineering Science and Technology, an International Journal | 1 |
| International Journal of Refrigeration | 1 |
| Isı Bilimi ve Tekniği Dergisi | 1 |
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Scholarly Output
10
Articles
8
Views / Downloads
13/62
Supervised MSc Theses
1
Supervised PhD Theses
0
WoS Citation Count
15
Scopus Citation Count
14
Patents
0
Projects
0
WoS Citations per Publication
1.50
Scopus Citations per Publication
1.40
Open Access Source
8
Supervised Theses
1
Scopus Quartile Distribution
Competency Cloud
