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In the present study, multi-layer calculations loops based on machine learning used to simulate the flow pattern and the thermal behavior through pore scale porous media (PSPM) walls, including phase-change materials (PCMs) in Trombe walls. A study of the thermal behavior of PSPM walls over a 24 hr period was conducted with a steady-state flow passing through the wall by applying the Monte-Carlo radiation model for the system. Constant-concentration PCMs help to reduce the temperature gradients between day and night. On the basis of porosity, solar radiation, heat flux, and time, a novel solution for prediction and optimizing the concentration of PCM in the Trombe wall was presented. For small components of PSPM, this method considers a high-fidelity CFD-based calculation. Following thorough validation, the values of velocity, pressure, and temperature for the fluid and solid zones were used as a training data set for machine learning. High-order optimization helps us to find the optimum PSPM wall porosity and PCM concentration (10% < epsilon < 90%, 0 < C*PCM < 9 x 103capsules.cm  3). The results indicated that the optimal combination of the PCM concentration and the wall porosity was epsilon = 48%, C*PCM = 7.1 x 103capsules.cm  3. According to the results, PCMs can reduce the temperature of PSPM wall (outer side) by 5.2% compared to the without PCM state over day and night. Furthermore, the temperature gradient over the course of the day was 6.34% lower than it is when PCMs are not used. For the period from 17:00 to 06:00, the average temperature of the PSPM wall with PCMs is up to 6.64% higher than it is without PCMs. We demonstrate how a combination of machine learning and numerical simulation can be used to predict the flow behavior and thermal pattern of a large PSPM Trombe wall. This solution may provide a framework to understand flow behaviour through complex geometry based on a micro-scale approach and long-term prediction for the macro-scale domain.

Current environmental concerns on nitrogen oxides (NOx) and particulate matter (PM) emis-sions caused by diesel engines have led researchers to be interested in investigating vehicles with alternative power sources. Because of this reason, vehicle models with SI engine were adopted in the conducted study. Firstly, as an initial step, 1-D SI engine models were created with use of AVL Boost software. A four-cylinder engine model was created for conventional vehicle model, while a two-cylinder downsized engine was adopted as a subsystem of hybrid vehicle model. The models were based on experimental data obtained from a laboratory test setup with a single-cylinder engine. Subsequently, detailed engine maps on emissions and fuel consumption were generated with the developed ANN model. The fuel consumption and emission data, which were gathered from NEDC and WLTC simulations, were compared for conventional ICE, PEM FC and PEM FC + ICE powered vehicles with the help of the vehicle model which was developed by using Matlab Simulink software. Based on the results, it was concluded that there might be sufficient improvement in fuel consumption and significant improvement in emissions with the use of PEM FC that a hybrid driving system (PEM FC + ICE) can be utilized, and that emissions can be at 0 with the sole use of PEM FC. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Günümüzde, buhar kazanlarının işletme şartlarını iyileştirme açısından bakıldığında enerji verimliliği endüstrideki en önemli unsurdur. Bu amaçla buhar kazanlarında baca gazından ısı geri kazanımı için genellikle besleme suyu ekonomayzerleri ve hava ısıtıcıları kullanılır. Baca gazı içindeki O2 (5.7%) ve CO (0%) hacimsel yüzdesi, baca gazı sıcaklıkları (100, 150, 168, 218 °C),ortam sıcaklığı (23.8 °C), yüzey sıcaklıkları (38.3, 40.8, 65.5, 132.5, 166.65 °C), besleme suyu sıcaklığı (108°C),ön ısıtılmış besleme suyu sıcaklığı (133 °C) ve buhar sıcaklığı (166.65 °C),doğal gaz tüketim miktarı (149.4 Nm3/15 dakika) , buhar tüketimi (2000 kg/15 dakika), besleme suyu iletkenliği (134.25 ppm), kazan suyu iletkenliği (3500 ppm), işletme koşulları (6.3 bar), mutlak basınç (7.3 bar) ölçümleri yapılmıştır. Sistem ekonomayzer veya hava ısıtıcı kullanılmadan, ekonomayzer kullanılarak, hava ısıtıcısı kullanılarak, hem ekonomayzer hem hava ısıtıcısı kullanılarak farklı şekillerde çalıştırılarak değerlendirilmiş, hem besi suyu ısıtıcısının ve ekonomayzerin ayrı ayrı ve birlikte kullanılmasının etkileri incelenmiştir. Bu nedenle, ölçüm sonuçları kullanılarak her durum için ayrı ayrı toplam ısı kaybı ve verim değerleri, yakıt tüketimi ve tasarruf miktarı, yatırım ve işletme-bakım maliyetleri hesaplanmış ve Net Bugünkü Değer ile İç Karlılık Oranı metodları kullanılarak ekonomik analizleri yapılmış, farklı uygulamalar birbirleriyle karşılaştırılmıştır. Bir gıda tesisindeki buhar kazanı için yapılan bu örnek çalışmanın tesislerinde ısı geri kazanım sistemi kuracak yatırımcılar için faydalı olacağı düşünülmektedir. Deneysel analizlerin sonucu olarak, baca gazından ısı geri kazanım metodunun bir kazanda enerji tasarrufu yapmak için en etkili metodlardan biri olduğu görülmüştür, Nowadays, energy efficiency is the crucial element in industry in terms of improving operating conditions steam boilers. Generally, feed-water economizers and air preheaters are used for this aim in steam boilers to recover heat from the flue gases. The measurements of volumetric percentages O2 (5.7%) and CO (0%) in flue gas, temperatures of flue gas (100, 150, 168, 218 °C), ambient (23.8 °C), surface (38.3, 40.8, 65.5, 132.5, 166.65 oC), feed-water (108°C) preheated feed water (133 °C) and steam (166.65 °C), consumption of natural gas (149.4 Nm3/15 mins) and steam (2000 kg/15 mins), conductivity of feed-water (134.25 ppm) and boiler water (3500 ppm), operating pressures (6.3 bar), absolute pressure (7.3 bar) are performed experimentally. Various case studies such as steam boiler operation without the use of economizer or air preheater, economizer addition to the steam boiler, addition of air preheater to steam boiler, addition of both economizer and air preheater to steam boiler are carried out to discuss the effects of the use of either feed-water economizer or air preheater separately and together. Consequently, total heat loss and efficiency values, fuel consumption and saving amounts, investment and operation-maintenance costs, some economic analyses using the methods of net present value and internal rate of ratio are calculated using measured values for each case study separately and compared with each other considering the case studies. It is expected from this study that investors will benefit from the calculation process used for an example application of steam boiler in a food plant to establish heat recovery systems in plants. As a result of experimental analyses, the heat recovery method from flue gas is found to be one of the effective processes to save energy in a boiler as expectedly

WOS: 000429178800003, This study presents a case study of energy management in a sugar factory in Turkey. The main idea of the study is to analyse energy consumption, the quantity of material production, and figure out a suitable energy efficiency for the case study of a sugar factory subsequently. Firstly, a material production and energy consumption audit were performed for the sugar factory. Secondly, energy efficiency was calculated from the energy data. The SPSS (Statistical Package for the Social Sciences) statistical software was used to ensure the accuracy of the data. The factory's energy consumption was calculated as 43,590.25 toe (tons of oil equivalent) over the last year. These results were used for CUSUM (Cumulative Sum Deviation Method) graphics. This research poses the consumption of energy, cost of energy and the relationship between energy usage and material production of sugar. The unit of energy cost was 688.22 [$/toe] for the last year. This result showed that the factory decreased the unit of energy by optimisation. The results indicated that the investigated sugar factory should pay attention to the energy management issue in order to comply with the Energy Efficiency of Turkish Law and Directives.