Zafer Utlu

Estimating Energy and Exergy Production and Consumption Values Using Three Different Genetic Algorithm Approaches. Part 2: Application and Scenarios

Abstract The main objective of the present study is to investigate the application of the genetic algorithm (GA) method with various scenarios for the future estimation of the energy and exergy production and consumption values. The methodology developed and presented in detail in Part 1 of this study was applied to Turkeys energy and exergy utilization values. Good correlations were obtained in all cases, indicating the validity of the models proposed that can be used to estimate total energy and exergy production and consumption of Turkey for the period of 2000–2020. It may be concluded that the models reported here will provide the investigators with knowledge about how a country can model its natural resources in terms of energy and exergy utilizations.

Comparison of Turkey's Sectoral Energy Utilization Efficiencies between 1990 and 2000, Part 2: Residential-Commercial and Transportation Sectors

Turkeys energy consumption and imports are experiencing rapid growth, as is the Turkish economy. Hence, rational and efficient utilization of energy resources is very essential. Therefore, knowledge of the Turkish energy utilization efficiencies is of paramount importance in establishing the energy policy of the country. The present study, consisting of two parts, analyzes sectoral energy utilization in Turkey over an 11-yr period from 1990 to 2000. In order to calculate sectoral energy utilization efficiency values, Turkey is subgrouped into four main sectors, namely, utility, industrial, residential-commercial and transportation. Part 1 of this study investigated the first two subsectors, while the rest is studied here. Turkeys overall first law efficiencies for the entire residential-commercial sector are found to vary from 54.19 to 57.76%, while those for the whole transportation sector are obtained to range from 20.15 to 23.88%, with average values of 56.21 and 21.70% for 11 years, respectively. Total energy utilization efficiencies are calculated to vary from 43.24 to 45.81%, with an average value of 44.66% for the same years. It is anticipated that the results obtained can assist national government for future planning studies. However, a good energy management system should be installed throughout the country for the optimum use of these resources.

Comparison of Turkey's Sectoral Energy Utilization Efficiencies between 1990 and 2000, Part 1: Utility and Industrial Sectors

Turkeys demand for energy has been rapidly increasing as a result of factors like industrialization, urbanization and rapid population growth. In meeting the increased demand, the efficient utilization of energy in all Turkish sectors plays an essential role. The present study, consisting of two parts, analyzes sectoral energy utilization in Turkey over an 11-yr period from 1990 to 2000. In order to calculate sectoral energy utilization efficiency values, Turkey is subgrouped into four main sectors, namely, utility, industrial, transportation, and commercial-residential. Part 1 of this study investigates the first two subsectors, while the remainder is treated in Part 2, where all the sectors considered are discussed in detail. Turkeys overall first law efficiencies for the entire utility sector are found to vary from 30.10 to 35.21%, while those for the whole industrial sector are obtained to range from 61.20 to 68.97%, with average values of 31.82 and 63.57%, respectively. It is anticipated that the present study will provide useful insights into the Turkish energy use and the planned studies towards increasing energy efficiencies in the sectors studied.

Genetic Algorithm (GA) Approaches for the Transport Energy Demand Estimation: Model Development and Application

This study deals with estimating future transport energy demand using genetic algorithm (GA) approach. Genetic algorithm transport energy demand (GATENDM) model is developed based on socio-economic indicators (population, gross domestic product (GDP), import and export) and transportation indicators/parameters (car, bus, and truck sales). The GATENDM model developed is applied to Turkey, which is selected as an application country. This model in a quadratic form was found to provide the best fit solution to the observed data. It may be concluded that the model proposed can be used as an alternative solution and estimation technique to available estimation technique in predicting the future transportation energy utilization values of countries.

Estimating Energy and Exergy Production and Consumption Values Using Three Different Genetic Algorithm Approaches. Part 1: Model Development

Abstract The present study, consisting of two parts, proposes new models for estimating energy and exergy production and consumption values using the genetic algorithm approach. Part 1 of this study deals with the model development, while the application and testing with various scenarios will be treated in Part 2. In this regard, the genetic algorithm energy (GAEN) and genetic algorithm exergy (GAEX) estimating models have been proposed. During the energy and exergy estimation, independent variables are the GDP, population, and the ratio of export to import. The three forms of the GAEN and GAEX are developed, of which one is linear, second is exponential and the third is a mix of the exponential and linear form of the equations. Among them, the best fit models in terms of average relative errors and for the testing period are selected for future estimation and proposed both for GAEN and GAEX. It may be concluded that the models proposed here can be used as an alternative solution and estimation techniques to available estimation techniques.

Performance Analysis and Assessment of an Industrial Dryer in Ceramic Production

In recent years, exergy analysis has been widely used in the design, operation, and performance assessment of various thermal systems, among which drying, which is an energy intensive operation, is of a great importance. In the ceramic industry, it is aimed at utilizing a minimum amount of energy in order to remove the maximum moisture for the desired final conditions of the product to be dried. In this study, energy and exergy analyses of a ceramic plant, located in Izmir, Turkey, with a yearly production capacity of 24 million m2 were performed using the actual operational data over a period of 12 months. The drying system at the three stages was analyzed and the values for exergy destruction and efficiency for each component of the system and the whole system at a reference (dead state) temperature of 22°C were calculated. For the month of January, energy and exergy efficiencies for the spray dryer (SD) were determined to be 65.50 and 53.7%, respectively. Energy and exergy efficiency values of the vertical dryer (VD) were 45.12 and 43.3%, respectively, and those of the furnace (F) were 35.08 and 16%, respectively. Based on this one-year assessment, the energy efficiency values for the SD, VD, and F varied between 58.48 and 65.50%, 42.44 and 50.87%, and 30.44 and 36.99%, and the exergy efficiency values were in the range of 44.85–65.16%, 34.92–45.42%, and 12.73–16.41%, respectively.

An Application of Genetic Algorithm Search Techniques to the Future Total Exergy Input/Output Estimation

Since 1975, there has been a great deal of interest, particularly during the past decade, in the promising genetic algorithm (GA) and its application to various disciplines from medicine to cogeneration. However, the studies performed on energy-related GA modeling are relatively low in numbers. The main objective of the present study is to develop the exergy input/output estimation equations in order to estimate the future projections based on the GA notion. In this regard, the GA Future Total EXergy Input/Output Estimation Models (GAFTEXIEM/GAFTEXOEM) are used to estimate total exergy input/output demand of Turkey, which is selected as an application country, based on the economic and social indicators of gross domestic product (GDP), population, import, export and house production figures. The future prediction of Turkeys total exergy input/output values are projected between 2003 and 2023. It may be concluded that the models proposed here can be used as an alternative solution and estimation techniques to available estimation techniques. It is also expected that this study will be helpful in developing highly applicable and productive planning for energy policies.

Determination of the Effect of Wall Heating Systems on Convective Heat Transfer Coefficient in Buildings

Decreasing energy consumption and advancing thermal comfort are the most important aims of building engineering. Previously reported studies by many researchers have found that different usages of convective heat transfer coefficient (CHTC) correlations in heating system simulations have considerable impacts on calculated heating load in buildings. Hence, correct utilization of CHTCs in real size room enclosures has great importance for both energy consumption and thermal comfort. In this study, a modeled room was numerically heated from one vertical wall and cooled from the opposite wall in order to create a real room simulation. While cooled wall simulate heat losses of the room, heated wall simulates the heat source of enclosure. Effects of heated and cooled wall temperatures and characteristic length on CHTC and Nusselt number in the enclosure were numerically investigated for two (2-D) and three dimensional (3-D) modeling states. CHTCs and Nusselt numbers of a real size room with the dimensions of 6.00 by 2.85 by 6.00 were found with FLUENT CFD and graphics of change were drawn. As result, difference between 2-D and 3-D solutions was found approximately 10%. This was attributed as the effect of air flow pattern effects over other surfaces in the enclosure that can not be counted at 2-D solutions. The change of CHTC at different characteristic lengths was illustrated as well.

Technical and Economic Performance Analysis of Utilization of Solar Energy in Indoor Swimming Pools, An Application

In this study, technical and economic performance analyses are conducted in order to determine the optimum collector surface area for indoor swimming pools. Required heat and economical conditions are taken into consideration while performing these evaluations. A brief summary of solar energy source and heat transfer equations for the Olympic pools are given. An Olympic swimming pool is assumed to be in different cities, and energy losses are calculated. For our sample Olympic pool, convective heat loss obtained is −3.86 kW and evaporative heat loss obtained is 265 kW. Total heat loss always maximum in January from 384 kW to 455.1 kW. Solar energy gain (assumption 1000 m2 collector area) and energy gain from boiler for different cities are calculated as maximum solar energy gain in July between 160 and 175 kW and minimum in January between 54.9 and 82 kW. High investment costs for solar power systems are responsible for low value of the reduction rate. Also, according to the energy demand and economical conditions, technical evaluations are performed in order to obtain optimum surface collector area, and economical analyses are conducted using unified cost method.

Analyzing the Energy Utilization Efficiency of Renewable Energy Resources. Part 1: Energy Analysis Method

Energy consumption depends mainly on the available amounts of local resources, which are closely connected with the present rural economy and living standards. Recently, there has been increasing interest in using energy and exergy modeling techniques for energy utilization assessments in order to attain energy savings, and hence financial savings. The energy utilization of a country can be evaluated using exergy analysis to gain insights into its efficiency. The present study, consisting of two parts, deals with analyzing the energy utilization efficiency of renewable energy resources (RERs). Part 1 uses energy analysis method, while exergy analysis method is applied to Part 2. In the analysis, Turkey with a projected population of 76,840,418 in 2010, is given as an illustrative example. RERs considered are residential-commercial and industrial subsectors used in the Turkish conversion. The energy efficiency values for Turkeys RERs are projected to be 60.99% in 2010. Besides this, total energy utilization efficiency values for those are expected to be 49.85% in the same year. The present study has clearly indicated the necessity of the planned studies towards increasing renewable energy utilization efficiency in the sub-sectors studied and especially the critical role of policymakers in establishing effective energy-efficiency delivery mechanisms throughout the country. It is also expected that this study will fill a considerably large gap since it is the first attempt towards analyzing Turkeys RERs in 2010 in terms of energy utilization efficiencies.