Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2024Effect of thickness and melting temperature of phase change material integrated into exterior wall on building energy performance and CO2 emission reduction; [Dış duvara entegre edilen faz değiştiren malzemenin kalınlığı ve erime sıcaklığının bina enerji performansı ve CO2 emisyon azalımına etkisi]
İlgar, Gamze; Terhan, Meryem
In the study, the effect of phase change materials integrated into the building's external wall has been investigated in terms of material type, thickness, and melting temperature of phase change material on the building energy performance for İzmir Province. A villa residential project has been modelled in 3D using DesignBuilder energy simulation software and two different external wall configurations have been designed by changing the position, thickness and melting temperature of the PCMs into the wall. The amount of CO2 emission reductions that PCMs will provide according to the fuel type of the building's heating system has been calculated. Using PCMs in the external wall not only provides high heating and cooling energy savings but also increases thermal comfort indoors by reducing temperature fluctuations. The PCM melting temperature of 23℃ performs quite well compared to other temperatures in both cooling energy and heating energy demand reduction. By increasing the triple thickness of the PCM, 18.81% in heating energy and 22.85% in cooling energy savings can be achieved. Depending on the external wall and phase change material types, different thicknesses and melting temperatures of PCM, annual total energy saving of the phase-change material is calculated between 10,349.50-83,345.98 kJ/m2.year and the annual CO2 emission reduction according to fuel types has been found as 0.672-14.284 kgCO2/m2.year.
- MakaleYalnız künye2024Waste Heat and Mass Recovery from Boiler Exhaust Gases in a New Generation District Heating System: Energy and Exergy Analysis
Terhan, Meryem
The study performs energy and exergy analyses for each component such as boilers, buildings, distribution networks and heat exchangers of a new generation district heating system. Energy and exergy efficiencies are compared for all system components, and energy and exergy losses are presented using Sankey and Grassman diagrams. Three flue gas condensers with finned bundles are designed for different capacities of boilers that intend to recover water and heat from the waste flue gas in the district heating system due to high flue gas energy losses. Colburn-Hougen and one-dimensional finite difference methods are used to design the flue gas condensers with the MATLAB program. The exergy analysis showed that the exergy input to the system is lost by 4.52% from the distribution networks, 4.15% from all buildings and 2.18% from the flue gas. In the system, the energy and exergy efficiencies of the boilers are calculated to be 87.23% and 17.32%, respectively, and the heat loss from the flue gas is found to be 12%. The design results show that the values of mass convection coefficient (km) for all flue gas condensers decrease from 0.0706 at the inlet condensation zone to 0.0354 towards the outlet. The total condensation rate and condensation efficiency are found to be 86 kg/h and 60%, respectively, for the 2500 kW boiler.
- MakaleYalnız künye2023Investigation of used PCM-integrated into building exterior walls for energy savings and optimization of PCM melting temperatures
Terhan, Meryem; Ilgar, Gamze
In the study, the effects on the building's thermal energy performance of using two different phase change materials (PCMs) integrated into the exterior walls at various thicknesses and melting temperatures have been investigated. Four exterior wall types have been designed by changing the position of PCM integrated into the exterior wall for the purpose to decrease heating and cooling energy demand. For each wall type, three different thicknesses (layers) have been studied and energy savings that PCM provided by decreasing the heating and cooling energy demands have been calculated on a monthly and annual basis. According to the energy simulation analyses, the configuration provided the highest heating energy savings (21.32 %) on an annual basis is the three-layer BioPCM27 integrated exterior wall with a melting temperature of 21 °C. The monthly optimum melting temperatures of PCMs have been determined based on the charge and discharge processes of PCM integrated into the exterior walls by evaluating the results of hourly energy simulation analysis. The annual average optimum melting temperature varies between 18 and 19 °C, depending on the exterior wall and material types. The three-layer (3L) InfiniteRPCM21C configuration (Type 3) has the best thermal energy performance among all exterior wall types, with 24.45 % total energy savings in the cooling season and 14.76 % in the heating season.
- MakaleAçık Erişim2023Energy, exergy analysis and optimization of insulation thickness on buildings in a low-temperature district heating system
Terhan, Meryem; Abak, Sena Saliha
In the study, energy and exergy analysis of the buildings on a campus in Turkey are conducted by using actual operating data and taking measurements in the district heating system as a case study. The energy and exergy demands, losses that stem from all buildings are calculated according to average daily outdoor temperature data. Due to the high heat losses in the buildings, determining the optimal insulation thickness for the exterior wall should be investigated. Therefore, optimal insulation thicknesses, energy savings, fuel consumptions and payback periods of the insulation material on the exterior wall of the building are examined by using Life Cycle Assessment and P1–P2 method for natural gas. Optimal insulation thicknesses are calculated for different insulation materials such as XPS, glass wool, rock wool and EPS for the climatic regions (HDD=800–4250°C days). According to average exergy losses from the building components per unit area, the average total exergy loss is calculated as 2.39×10-2 kW/m2.year and 1.42×10-3 kW/m2 (5.92%) of this loss stems from the exterior walls, 1.93×10-3 kW/m2 (8.07%) from the floors, 7.37×10-4 kW/m2 (3.08%) from the roofs, 1.58×10-2 kW/m2 (65.99%) from the windows and doors, 4.04×10-3 kW/m2 (16.92%) from the ventilation with infiltration. Energy requirement values of the building are found between 2.68–25.70 kWh/m3 towards from the warmest to the coldest climatic region for the uninsulated wall. In the un-insulated state, fuel consumption varies between 1.93-18.48 m3/m2 from the warmest to the coldest region. The optimal insulation thickness values of the building’s exterior wall are calculated as between 2.3–10.0 cm according to different climatic regions. In-state of exterior wall insulation of 3 cm, fuel consumption decreases by 46.63%–53.46% compared to different insulation materials and climatic regions compared to the un-insulated state
- MakaleAçık Erişim2023Energy and economic assessments of waste heat recovery by designs of economizer, condensing economizer and air preheater; [Ekonomizer, yoğuşmalı ekonomizer ve hava ön ısıtıcı tasarımları ile atık ısı geri kazanımının enerji ve ekonomik değerlendirilmesi]
Terhan, Meryem; Özağdaş, Emre; Omar, Muhammed Arslan
In this study, the waste heat loss of flue gases from the boilers of Kafkas University district heating system has been calculated between 6-8% according to the combustion analysis and the annual cost of this heat loss has been found as $58,658.79. In terms of energy efficiency and the national economy, we think that this lost energy should be recovered as much as possible and fuel and energy savings should be achieved. In the paper, the effects of variants such as air excess coefficient, flue gas temperature, boiler capacity and fuel consumption on the heat recovery from flue gas have been presented in detail. The heat recovery scenarios have been presented for reusing this waste energy for space heating, domestic hot water, and preheating combustion air and the applicability of these scenarios has been investigated in terms of thermodynamics and economics. According to the results of the study, in the second scenario examined to cover the domestic hot water need of the guest house building, the energy savings of the scenario can be provided during 20 years of economic life is $122,820.83, and it has the highest savings income among the scenarios. In addition, it is possible to recover approximately 50% of the flue gas loss with thanks to the scenario. On the other hand, the third scenario of heating the boiler combustion air with waste heat is the easiest and most economical scenario because its payback period is only one year, and there are no extra excavation and pipe costs.
- MakaleAçık Erişim2022Optimization insulation thickness and reduction of CO2 emissions for pipes in all generation district heating networks
Terhan, Meryem
District heating systems are provided solutions for the increasing energy problems in high-population cities. Energy costs go up depending on increasing heat loss in DHS's distribution network. Heat loss from the network consists of 5–20% of transferred energy, and this loss is higher than the other losses in the heating system. In the study, heat losses from the pipes such as supply-return pipes, hot water and circulation pipes into heat canals are investigated based on energy, exergy, economic and environmental. Optimum insulation thicknesses, energy savings, reduction of CO2 emissions, the first investment costs and payback periods of the pipes in the network of all-generation district heating systems are investigated by using Life Cycle Cost Analysis (LCCA) method for fuel types like natural gas, fuel oil and coal. Optimum insulation thicknesses are calculated for different nominal sizes of pipes and various insulation materials such as glass wool, and rock wool for the different climatic zones. According to the results of the study, the heat losses from pipes in the 4th generation DHS network are decreased between 38.19% and 33.33% from the warmest climate zone to the coldest climate zone according to the 3rd generation. Energy savings, reduction of CO2 emissions, payback periods and optimum insulation thickness values of supply and return pipes in the network are respectively changed between 7.80–98.86 $/m, 39.61–322.32 kg CO2/year, 0.028–0.38 years and 0.025–0.0105 m depending on various fuel types, insulation materials, nominal size pipes, climatic zones and all generation types.
- MakaleYalnız künye2021Investigation of Effect of Dew Point Temperatures on Design of Condensing Heat Recovery Units According to Fuel Types
Terhan, Meryem
In this study, dew point temperatures of water and sulphuric acid vapour in flue gas are predicted as theoretical for fuels types such as coal, fuel oil, natural gas, LPG, wood with the different cities in Turkey. The factors like the excess air coefficient, relative humidity rate and the altitude of the city affected by the dew point temperatures and the mole ratios of water and sulphuric acid vapour in flue gas are studied. According to the results of the study, while the water dew point temperature changes for coal, wood, fuel oil, natural gas and LPG, over the range 30-40 degrees C, 40-50 degrees C, 37-50 degrees C, 44-60 degrees C and 41-56 degrees C, respectively; the acid dew point temperature waves to 125 degrees C from 140 degrees C for coal types and to 131 degrees C from 145 degrees C for fuel oil types in Turkey. To predict the condensing zone, a condensing economizer for a natural gas-fired boiler in a heating system is designed with Finite difference method. According to the results of the design, while the first 100 m of the heat exchanger tube is non-condensing zone, the only 10 m is the condensing zone.
- MakaleAçık Erişim2021PREDICTION SULPHURIC ACID AND WATER VAPOUR DEW POINT TEMPERATURES OF FLUE GASES AND COMBUSTION ANALYSIS FOR SOLID FUELS IN TURKEY
Terhan, Meryem
In the study, the combustion analysis is examined for the solid fuels in Turkey. The principal aim of the analysis is determined the limits and obstacles in the design heat exchanger to avoid the corrosion risk on the heat exchanger surfaces in the latent heat recovery applications from waste flue gas. To do this, in which regions of the heat exchanger the flue gas temperature reached to the sulphuric acid and water vapour dew point temperatures are required to predict. In order to predict the condensing zone, an air preheater for the coal-fired boiler in a heating system is designed using finite difference method. Designed the air preheater is consists of the counter-cross flow, U-shaped stainless steel tube bundle. The tube is discredited 200 cells to one-dimensional during the flow. The heat transfer rates, the flue gas and air inlet and outlet temperatures, surface temperatures of the tube wall, the mole fractions of water and sulphuric acid vapour, the other non-condensing gases in the flue gas are calculated in each discrete cell. According to the results of the study, while the dew point temperature of the water vapour changes over the range 30-40 °C, the acid dew point temperature waves to 125 °C from 140 °C for the coal types mined in Turkey.