Yazarlar
- Cuce, Erdem(25)
- Cuce, Pinar Mert(20)
- Tozlu, Alperen(17)
- Karaali, Rabi(11)
- Guclu, Tamer(10)
- Kahveci, Hakan(7)
- Özahi, Emrah(6)
- Keven, Arzu(5)
- Çorapsız, Muhammed Reşit(5)
- Bayram, Ozkan(4)
- Ceviz, Mehmet Akif(4)
- Igman, Erdal(4)
- Imamoglu, Ilyas Kays(4)
- Isik, Cem(4)
- Karaali, R.(4)
- Kosunalp, Selahattin(4)
- Köksal, Hüseyin(4)
- Ongan, Serdar(4)
- Ozel, Faruk(4)
- Ozel, Sultan Suleyman(4)
- Tozlu, A.(4)
- Abusoglu, Aysegul(3)
- Abuşoğlu, Ayşegül(3)
- Güngör, Okan(3)
- Korkmaz, Şadan(3)
- Kus, Mahmut(3)
- Kuziboev, Bekhzod(3)
- Pat, Suat(3)
- Sari, Fahriye(3)
- Simsek, Onder(3)
- Uyar, Mehmet(3)
- Çakir, Uǧur(3)
- Çomakli, Kemal(3)
- Özen, Soner(3)
- Şenay, Volkan(3)
- Abuşoǧlu, A.(2)
- Afshari, Faraz(2)
- Aloui, F(2)
- Arslantürk, Cihat(2)
- Atabani, A.E.(2)
Yayınlar
- MakaleYalnız künye2024Scopus SJRQ1Design, modelling, environmental, economic and performance analysis of parabolic trough solar collector (PTC) based cogeneration systems assisted by thermoelectric generators (TEGs)
Cuce, Pinar Mert; Guclu, Tamer; Cuce, Erdem
Concentrating solar power systems (CSP) is a very efficient technology for clean and renewable energy production. It basically works on the principle of focusing the sun's rays with the help of a reflective surface. There are two types of CSP systems: point-focused and line-focused. Point-focused ones are parabolic dish collectors and solar towers. Line-focused ones are parabolic trough collectors (PTCs) and linear Fresnel reflectors. It is possible to reach focus temperatures over 1000 °C with point-focused CSPs. Line-focused CSP systems are used to obtain thermal and electrical energy at temperatures below 500 °C. Among CSP technologies, PTCs are widely preferred. While it can be used alone, it can also be used in combination with other power generation systems by creating hybrid systems. In this regard, hybrid PTC/TEG energy systems created with thermoelectric generators (TEGs) come to the fore. These systems have higher electrical and thermal efficiency values compared to traditional PTCs. In this study, CSP systems, PTCs, TEGs and hybrid solar energy systems-based PTCs were examined in detail. It is concluded from the study that the total thermal efficiency of PTC-TEG hybrid systems can be enhanced by up to %70 with respect to PTC systems.
AtıfScopus42WoS40OpenAlex37
İncele - MakaleYayıncıda açık erişim2024Scopus SJRQ1Energy, exergy, environmental, and enviroeconomic (4E) analysis of cascade vapor compression refrigeration systems using nanorefrigerants
Yılmaz, Metin; Cimşit, Canan; Keven, Arzu; Karaali, Rabi
The refrigerants used in traditional vapor compression refrigeration systems are harmful to the ozone layer and contribute to global warming. The demand for refrigeration is increasing because of global warming. In this study, for the first time, an energy, exergy, environmental, and enviroeconomic (4E) analysis was performed using different refrigerants and nanoparticles to reduce the energy required in low-temperature vapor compression cascade refrigeration systems and to determine more environmentally friendly nanorefrigerants. The R290 refrigerant was used for the Low-Temperature Circuit (LTC), while the High-Temperature Circuit (HTC) used RE170, R1234yf, R600, R600a, and R450A refrigerants. The nanoparticles used in the analysis were Al2O3, CNT, CuO, TiO2, ZnO, and SiO2. The R600 nanorefrigerant performed the best, whereas the R1234yf nanorefrigerant performed the worst. The results indicate that the CuO nanoparticles provided the highest performance. In addition, the results showed that the R290+R600-CuO nanorefrigerant emitted 11 % less CO2 than the pure R290+R600 refrigerant. The nanorefrigerants provide a more environmentally sustainable option because of their high efficiency and lower energy consumption than conventional refrigerants.
AtıfScopus9WoS7OpenAlex8İncele - MakaleAçık Erişim2024Scopus SJRQ1Analysis of cascade vapor compression refrigeration system using nanorefrigerants: Energy, exergy, and environmental (3E)
Yilmaz, Metin; Cimsit, Canan; Keven, Arzu; Karaali, Rabi
Nanorefrigerants are considered the most efficient heat transfer fluids for improving heat transfer properties in the refrigeration and air conditioning equipment. For the first time in this study, energy, exergy, and environmental evaluation (3E) analyses were performed by the addition of different nanoparticles to a low GWP refrigerant pair such as R290/R1233ZDE in a cascade refrigeration system. CNT, CuO, and, TiO2 nanoparticles were added to the refrigerant. The effect of nanoparticles on the cascade refrigeration system was analyzed using a model based on density changes. A detailed thermodynamic analysis was performed of the cascade refrigeration system at different evaporator temperatures and mass ratios. The power consumption of the compressor decreases as the evaporator temperature increases for all types of nanoparticles, resulting in an increase in COP values. The analyses showed that CuO nanoparticles had the highest performance. It has been observed that the energy and exergy efficiency increase as compressor work decreases with increasing mass ratios in all nanorefrigerants. In addition, the results indicated that all nanorefrigerants emit lower monthly CO2 emissions compared to the pure refrigerants. The nanorefrigerants play a crucial role in reducing energy consumption and promoting environmental protection compared to traditional refrigerants.
AtıfScopus16WoS16OpenAlex17İncele - MakaleAçık Erişim2024Scopus SJRQ3Exergetic Analyses of Detonation Engine Cogeneration Plants
Çakmak, Bahar; Karaali, Rabi
Efficiency improvements are very important in all research and technology. Detonation engines are high technology devices. In the last decades they attracted attention by many researchers. However, detonation engines for cogeneration are not researched efficiently. This article is about the detonation engines cogeneration cycles which analysed by using 1. and 2. law of thermodynamics and exergy analyses methods by the authors. The exergetic performance analyses, their advantage and disadvantages of the ZND-HRSG detonation engine cogeneration cycles were obtained. The exergetic performance analyses were done for various excess air rates to obtain the variations of the combustion exit pressures and temperatures, exergy efficiencies, electric heat rates, SFC and other parameters of their performance. Also, an optimization analysis was done for the ZND-HRSG by searching the optimum values for different excess air rates. The results showed that, the ZND-HRSG cycle have the optimum values of the performance at 1.6-1.8 of the excess air rates.
AtıfScopus1OpenAlex5
İncele - MakaleAçık Erişim2024Scopus SJRQ1Energy-driven TBM health status estimation with a hybrid deep learning approach
Li, Yongsheng; Zhang, Limao; Pan, Yue; Tapkın, Serkan; Song, Xieqing
This study provides a hybrid deep learning approach that enables the researchers to estimate the Tunnel Boring Machine (TBM) health status during excavation process using energy consumption data. By analyzing the energy forms and paths in the tunneling process, the key energy factors' consumption performance behavior affecting TBM safety is identified. The Ensemble Empirical Mode Decomposition (EEMD) method and a Convolution neural network-Long short term memory-Depth Neural Network (CNN-LSTM-DNN, CLDNN) model are integrated for Health Performance Parameter (HPP) prediction. A classification method is constructed by the Generative Adversarial Imputation Networks (GAIN) model for health status estimation. The SHapley Additive exPlanations (SHAP) method is performed to quantify the relationships between energy consumption and system health status. A tunneling case in Singapore is used to test the effectiveness of the developed methodology. It is found that (1) the proposed method provides TBM cutter wear and cooling oil prediction with a R-square (R2) of 0.8591 and 0.8727, respectively, and (2) classification results indicate that the estimation F1-score of 0.9863 can be achieved based on health status evaluation indicator (HSEI). The novelty of the proposed approach lies in its capabilities of (1) fully extracting and utilizing the energy consumption information in every regard to predict TBM health performance; (2) providing a good one-step-ahead health status estimation for the TBM excavation process. Therefore, this study proposes a feasible direction for the application of energy consumption data in TBM health status estimation.
AtıfScopus17WoS15OpenAlex17İncele - MakaleAçık Erişim2024Scopus SJRQ1Thermal and energy analysis of a novel solar updraft tower design with divergent chimney and convergent collector concept: CFD analysis with experimental validation
Cuce, Pinar Mert; Saxena, Abhishek; Cuce, Erdem; Kontoleon, Karolos J.; Oztekin, Erman K.; Shaik, Saboor; Guo, Shaopeng
The fact that energy sources are heavily dependent on fossil fuels increases the need for alternative energy day by day. Solar energy is the most popular alternative energy source with massive potential. Solar chimney power plants (SCPP) are one of the systems of interest based on solar energy. SCPP systems are rare systems that can provide 24-hour power output. Their performance has been the subject of constant research since the first pilot plant in Manzanares. Design is crucial for performance figures of SCPPs, and the limitation of climatic parameters causes the system to be approached with different designs. This study makes a 3D CFD model by combining the divergent chimney and convergent collector structure based on the first pilot plant. The solar ray tracing algorithm and the RNG k-e turbulence model are applied and the model equations are solved under dynamic conditions with the reliable software ANSYS FLUENT. After the mesh-independent solution of the model is complete, it is validated with experimental data. The two cases are compared for solar radiation of 1000 W/m2 and environmental temperature of 293 K. A power output of 50.51 kW is achieved for standard pilot sizing. With the new model, the power output rises to 146.34 kW. It is seen that the divergent chimney and convergent collector affect the airflow in the system, increasing the maximum air velocity to 19.363 m/s. In parallel with the experimental data, it is seen that the temperature on the ground exceeds 360 K in the CFD results.
AtıfScopus17WoS12OpenAlex14İncele - MakaleYalnız künye2023Mekânsal Panel Modelleri Kullanılarak Yenilenebilir Enerji Tüketimi, Çevresel Bozulma ve Büyüme İlişkisinin İncelenmesi: Balkan Ülkelerinden Kanıtlar
Arı, Ari; Bayramoglu, Turgut; Sayar, Ramazan
Amaç: Bu çalışmayla karbon salınımının Balkan ülkeleri ve Türkiye'nin büyümesine etkisinin olup olmadığının, eğer varsa, bu etkinin ne yönde ve ne yoğunlukta olduğunun bulunması amaçlanmıştır. Yöntem: Bu çalışmada karbon emisyonları ve yenilenebilir enerji üretiminin Türkiye ve 12 Balkan ülkesinin büyümesine etkileri analiz edilmiştir. Çalışmada mekânsal etkileşimleri ortaya çıkarabilmek için Mekânsal Otokorelasyon Analizi yapılmıştır. Büyümeyi etkileyen faktörleri incelemek için ise Havuzlanmış En Küçük Kareler yöntemi kullanılmıştır. Bulgular: Çalışmanın sonuçlarına göre Balkan ülkelerinde yenilenebilir enerjinin büyüme üzerindeki olumsuz etkisinin, yenilenebilir enerjinin henüz gelişme aşamasında olması ve üretimdeki payının hala düşük olmasından kaynaklandığı söylenebilir. Yenilenebilir enerji sektöründeki yatırımların sınırlı olması yenilenebilir enerji sektörünün yavaş yayılmasına neden olmaktadır. Özgünlük: Çalışmada farklı bir yöntem olarak mekânsal panel modellerinin kullanılması ve kapsamın Türkiye ile sınırlı tutulmayıp tüm Balkan ülkelerini de kapsaması bu çalışmanın özgün değerini oluşturmaktadır.
AtıfOpenAlex1İncele - MakaleAçık Erişim2023Farklı Yabani Brassica Tohumlarının Yağ Asidi Kompozisyonu ve Biyodizel Kalitesi
Girgel, Umit; Onemli, Fadul; Gıdık, Betül; Gül, Volkan
Her geçen gün artan dünya nüfusu ve gelişen sanayi alanları enerjiye duyulan ihtiyacı da artırmaktadır. Bu durum alternatif ve yenilenebilir enerji kaynaklarını ve bu kaynakların verimli kullanımı konusunu daha değerli kılmaktadır. Bu çalışmada, yabani türlerin biyodizel üretiminde kullanılabilirlik potansiyelini belirlemek amacı ile Türkiye’nin Bayburt ili ekolojik koşullarında yetiştirilen Brassicaceae familyasından Sinapis arvensis, Brassica nigra ve Brassica napus tohumlarının biyodizel kalite özellikleri ve GC-MS kullanılarak yağ asitleri kompozisyonu bölge için ilk kez belirlenmiştir. Brassicaceae familyasından çalışmada yer alan türlerin yağ verimi %30,29-46,02 arasında bulunmuştur. Ayrıca linolenik asit (%7,62-13,70) değerleri en düşük B.napus, en yüksek B.nigra’da belirlenmiştir. Parlama noktası bakımından (194-195℃) B.napus ve S.arvensis birbirine en yakın türler olduğu görülmüştür. S.arvensis ve B.nigra’nın yağ asidi kompozisyonu ve biyodizel kalite analiz sonuçları B.napus’a benzer değerlerde bulunmuştur. Yabani türler olan S.arvensis ve B.nigra’nın biyodizel kalite özellikleri ve yağ asitleri kompozisyonu bakımından yenilenebilir enerji üretim potansiyeline sahip olduğu görülmüştür.
AtıfOpenAlex3TR Dizin1İncele - Derleme MakaleYalnız künye2023Scopus SJRQ3An overview of frequency-based power split strategies in electric vehicles with battery/supercapacitor hybrid energy storage system
Çorapsız, Muhammed Reşit; Kahveci, Hakan
Energy management in hybrid energy storage systems (HESSs) consisting of battery and supercapacitor packages has an essential role in the efficient and safe use of energy storage devices. In the mentioned HESSs, with frequency separation-based energy management, the source with slow dynamics (eg, batteries) is supported by other sources with fast dynamics (eg, supercapacitors). To realize power sharing in the battery/supercapacitor HESS, the load current is divided into low- and high-frequency components and supplied/allocated from energy storage devices. This review touches on the historical development of electric vehicles and includes extensive information about the battery and supercapacitor. It also comprehensively analyzes frequency separation-based power allocation strategies for battery/supercapacitors HESS. These strategies were investigated in detail regarding their features, advantages, and restrictions. In addition, interconnection circuit topologies and control techniques used in frequency-based power allocation were explained comprehensively. As a result, this study will serve as a guide on frequency-based power separation principles in HESS.
AtıfScopus23WoS14OpenAlex22İncele - MakaleAçık Erişim2023Scopus SJRQ1The effect of various industrial dust particles on the performance of photovoltaic panels in Turkey
Güngör, Okan; Kahveci, Hakan; Gökçe, H. Süleyman
The accumulation of dust is one of the main causes of power loss in photovoltaic (PV) farms, and the effect of dust particles’ size and chemistry on system performance is often overlooked. This study has focused on a comprehensive analysis of the effect of different dust particles collected from common industrial production facilities in Turkey on the performance of PV panels in the indoor laboratory environment. The collected dust samples were analyzed to determine the dust sample particles’ chemical properties, size, character, and topography. The data for dust samples at different weights with changes in maximum power point (MPP) of PV panel has been collected using the artificial solar irradiation source system. Thus, the mathematical correlations (R2≥0.965) between the PV panel Thevenin resistance (RTH), fill factor (FF), MPP, and pollution rate were obtained using these collected data and particle swarm optimization (PSO). According to the results of the obtained mathematical correlations, marble dust is 2.3, 3.4, and 4.2 times less polluting than cement, fly ash, and silica fume, respectively. Additionally, it was observed that smaller dust particles block more light than larger ones of the same weight and reduce MPP, FF while increasing the RTH.
AtıfScopus19WoS14OpenAlex21
İncele - MakaleAçık Erişim2023Performance Analyses of Combined Cycle Power Plants
Karaali, Rabi
In this article, different compressor pressure and different excess air rates for a gas turbine based combine cycle power plant with steam Rankine cycle as bottoming cycle were analyzed by using 1. and 2. laws of thermodynamics and exergy analyses methods to obtain the best performances of the cycle. Exergy efficiency of the cycle, net powers of the gas and steam turbines and the overall cycle, exergy loss of the components, the efficiencies of the components are obtained, compared and discussed. It was found that, increasing the compressor pressure increases exergy efficiency of cycle, gas turbine and total plant power, and the combustion chamber, the HRSG and the compressor efficiencies. However, increasing compression rates decreases steam turbine power, combustion chamber, steam turbine, and HRSG exergy losses and the gas turbine efficiency. Also, it is found that, increases in excess air ratios gives an optimum or a maximum exergy efficiency, at 2.5 excess air rate of the cycle.
AtıfScopus3OpenAlex6İncele - MakaleAçık Erişim2023Scopus SJRQ1Evaluation of Optimal Energy Productıon Usıng Deterministic, Probabilistic and Risky Cases In a Multi-Reservoir System
Bacaksız, Efsun; Opan, Mücahit; Kara Dilek, Zuhal Elif; Karadeniz, Murat
In a multi-reservoir system, the stochastic nature of basin data resulting from rainfall introduces risk into water management operations. Effective management that accounts for these risks can obtain maximum benefits from the system. This study presents a description of a multi-reservoir water resources system with hydroelectric power plants, utilizing the energy optimization model developed by OPAN in 2007. The model was applied to reservoirs located successively on the Lower Kızılırmak River in the Kızılırmak Basin, with the objective function being the maximization of firm power by using drought period inflows and total energy by using monthly average inflows. The study considered three scenarios: deterministic, probabilistic, and risky (critical cases), with probabilities of inflows from the basin being determined for the latter. Monthly inflows with determined probabilities were used to obtain data for the risky case. Optimum operating levels were determined based on this data to maximize firm power and total energy. According to the operating levels, the reservoir with the largest useful volume manages the operation. The values obtained from the optimization were then used in multivariate regression analysis using the Statistical Package for Social Scientists (SPSS), a statistical analysis program. The analysis explored the effects of monthly operating levels in the reservoirs, the amount of inflow released from the spillway, the amount of inflow released for energy production, the monthly average inflow to the reservoirs, and firm power values on energy production.
AtıfScopus7WoS6OpenAlex7İncele - MakaleAçık Erişim2023Scopus SJRQ3A study on Li-ion battery and supercapacitor design for hybrid energy storage systems
Çorapsiz, Muhammed Reşit; Kahveci, Hakan
This paper discusses a generic design of lithium-ion (Li-ion) batteries and supercapacitors, which are important sources for energy storage systems (ESS). The main contribution of this study is to compare the available and experimental models for batteries and supercapacitors operating under continuous charge or discharge conditions. Even though the available models show similar behavior to the experimental ones in short-term or pulsed discharge conditions, this situation may be different in continuous discharge conditions. For this purpose, the optimal electrical equivalent circuits of energy storage devices were constituted and modeled in the MATLAB/Simulink environment. Then, the electrical equivalent circuit parameters were approximately calculated with the help of dynamic equations. Finally, the model parameters were estimated using Nonlinear Least Squares Method (NLSM) and Trust Region Reflective Algorithm (TRRA). When the obtained results were evaluated together, it has been observed that the electrical equivalent circuit models (EECM) more accurately reveal the transient and steady states of energy storage devices compared to the available models, especially under continuous discharge conditions.
AtıfScopus33WoS30OpenAlex33İncele - MakaleYalnız künye2023Scopus SJRQ1Novel PV Array Reconfiguration and Integration with a Maximum Power Point Tracking Algorithm: RMPPT
Güngör, Okan; Kahveci, Hakan
Partial shading significantly impacts the output power of photovoltaic (PV) arrays. This issue can be addressed by reconfiguring connections or positions of modules within the PV array. However, reconfiguration approaches present some drawbacks including the requirements of manual effort, complex algorithms, difficulty in implementation, and switching matrices that increase power losses. To overcome these issues, we present a low-cost and easily implemented reconfiguration method with integration into a maximum power point tracking (MPPT) algorithm for a PV array. We denote our MPPT approach as reconfigurable MPPT (RMPPT), and verify its applicability using a particle swarm optimization (PSO) algorithm, namely the reconfigurable PSO. Consequently, this approach has enhanced the output power of the PV array by at least 7.2% compared to PNO (perturb and observe) and PSO-based MPPT under realistic weather conditions.
AtıfScopus6WoS5OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ1A novel ignition timing strategy to regulate the energy balance during the warm up phase of an SI engine
Koksal, Hüseyin; Ceviz, Mehmet Akif; Yakut, Kenan; Kaltakkiran, Galip; Özakin, Ahmet Numan
The warm up characteristics of an engine have a significant impact on engine performance and exhaust emissions. In SI engines, the light-off performance of the catalytic converter is also important. One of the methods used to shorten the light off time of the catalytic converter is to retard the ignition time. When the ignition time is retarded, the temperature of the exhaust gases increases. However, in this case, the warm up performance of the engine itself may be adversely affected. In this study, firstly, the effects of ignition timing on the energy balance during the warm up period in an SI test engine were revealed. Then, a novel ignition timing strategy was proposed in order to increase the temperature of the exhaust gases, and not to reduce the engine performance. The novel ignition timing strategy working on the principle of sequentially advanced and retarded ignition at certain intervals during the warm up period provides several advantages. When the novel ignition strategy is applied, the energy loss through the exhaust gas was increased up to 7.2% for several operating conditions, while the reduction in engine performance is eliminated. Moreover, 20% reduction in NO emission has been achieved.
AtıfScopus8WoS8OpenAlex7İncele - MakaleAçık Erişim2022Scopus SJRQ3Turkey's Long-Term Electricity Consumption Forecast
Emec, S.; Akkaya, G.
Demand forecasting is essential primarily for planning. Although it is crucial in many sectors and issues, it has particular importance for electricity. Therefore, the issue of electricity consumption forecasting has recently become a prevalent topic. In light of the above, this study aimed to develop an appropriate model to estimate the long-term electricity consumption of Turkey. The study consists of three steps. In the first step, eight models were developed to separately investigate the effects of eight input variables frequently used in electricity consumption forecasting studies in the literature. In the second step of the study, two models consisting of input variables with high impact in the first step were developed, and the trained performances of the developed models were calculated by using the regression analysis. In the final step, the combined effect of eight variables on electricity consumption forecasting was investigated using regression analysis. It can be conclude that the model in the third step showed significant results, and the model performance was good. Finally, Turkey's electricity consumption forecast for the years 2020-2030 was performed using the model in the third step.
AtıfWoS1OpenAlex3İncele - MakaleAçık Erişim2022Scopus SJRQ2Investigation of inlet air pressure and evaporative cooling of four different cogeneration cycles
Karaali, Rabi
The objective of this study was to search the effects of the inlet air compressor pressure and evaporative cooling of four different cogeneration plants that are absorption cooling (ab), basic (bsc), air heating (airh), and air fuel heating (airfh) cogeneration systems by using the first law and the second law of thermodynamics, and the exergy analysis methods. For analysis, a program is written by the author in the FORTRAN programming language. Decreasing the atmospheric pressure or increasing the installation altitude of the plants increases the Z factor (ratio of lost exergy to useful exergy) of the four cycles about 10-13%. Also, decreasing inlet air pressure decreases the specific work about 25-28%, and the fuel energy saving ratio of the four cycles decreases about 29-30%. The method of water spray cooling of the compressor inlet air especially in the summer months, the humidity increases and the evaporative cooling can be obtained. By using this method, the ratio of lost exergy to useful exergy can be decreased for the four cycles about 0.5-2%. Also, the specific work of the four cycles can be increased about 1.2-6%.
AtıfOpenAlex4İncele - MakaleAçık Erişim2022Scopus SJRQ2The Investigation of COD Treatment and Energy Consumption of Urban Wastewater by a Continuous Electrocoagulation System
Dede Sağsöz, Yeşim; Yilmaz, Alper Erdem; Ekmekyapar Torun, Fatma; Kocadağistan, Beyhan; Kul, Sinan
In this study, electrochemical treatment of urban wastewater with electrical conductivity of 1000 µS cm-1 and chemical oxygen demand of 250 mg L-1 was investigated using the variables of initial pH value, current density and flow rate. Electrocoagulation was used, in which aluminum and stainless steel were selected, as the electrochemical treatment process. The electrocoagulation process was operated in continuous mode. The data obtained in experimental studies show that the best COD removal efficiency occurred in experiments where the initial pH value was 6. The increase in current density from 5 A to 15 A decreased the removal efficiency from 79 to 67%. The increase in flow rate under constant current density also reduced the efficiency of removal as expected. In experiments in which current density and flow rate were examined together, the increase in flow rate allowed the application of higher current densities. This situation led to considerable reductions in energy consumption values, even if the COD removal efficiency did not significantly increase. The high COD removal obtained with the use of high flow rate and high current density indicates that the electrocoagulation process can be used for high flow rate municipal wastewater treatment.
AtıfScopus6WoS5OpenAlex5İncele - MakaleAçık Erişim2022Scopus SJRQ3Evaluation of four different cogeneration cycles by using some criteria
Karaali, Rabi; Keven, Arzu
The purpose of this article is to evaluate four different gas turbine cogeneration cycles which are basic, absorption cooling, air heating and air fuel heating cogeneration cycles by using the most important six evaluation criteria for different excess air coefficient, different compression rates, and different compressor inlet air temperatures. These six evaluation criteria are electrical heat ratio, exergy efficiency, incremental heat rate, artificial thermal efficiency, fuel energy saving ratio, and specific fuel consumption. It is seen that the air-fuel heating cogeneration cycle is the most efficient among the cycles examined for a certain compressor compression ratio, followed by the air heating, basic, and absorption cooling cycles.
AtıfScopus20WoS18OpenAlex30İncele - MakaleAçık Erişim2022Scopus SJRQ3A Two-Stage ORC Integration to an Existing Fluidized Bed Sewage Sludge Incineration Plant for Power Production in the Scope of Waste-to-Energy
Abusoglu, A.; Tozlu, A.; Anvari-Moghaddam, A.
This paper presents the design, evaluation, and optimization of an electricity generation system based on the two-stage organic Rankine cycle (TS-ORC), which utilizes the waste heat of an existing fluidized bed sewage sludge incineration (FBSSI) facility. The facility incinerates an average of 300 tons per day of sewage sludge with a dry matter content of 22%. After the drying process, the sewage sludge is burned in a fluidized bed combustor, and exhaust gas at a temperature of about 850-900ºC is released due to the combustion. The system provides the energy required to dry the sludge from this exhaust gas. In this study, a TS-ORC is designed to be coupled to the exhaust gas flowlines discharged to the atmosphere at two different points in the FBSSI plant. The exergy efficiency of the FBSSI facility is found to be 70.5%. Three different working fluids are selected to examine the variations of thermodynamic and thermoeconomic performance parameters of the designed TS-ORC system. The highest power generation in the TS-ORC system (183.40 kW) is achieved using R1234yf as working fluid. R1234yf is also the most expensive fluid for electricity generation among the other working fluids (10.57 $/h). The least electricity generation in the TS-ORC (142.70 kW) occurs at the thermoeconomically most affordable cost with R245fa (9.35 $/h).
AtıfScopus2WoS2OpenAlex2İncele
