Energy Systems Engineering / Enerji Sistemleri Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4752
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Article Citation - WoS: 29Citation - Scopus: 33The Effect of Heat Transfer Characteristics of Macromolecule Fouling on Heat Exchanger Surface: a Dynamic Simulation Study(Wiley, 2023) Karimi Shoar, Zahra; Pourpasha, Hadi; Zeinali Heris, Saeed; Mousavi, Seyed Borhan; Mohammadpourfard, MousaAt the city gate gas pressure reduction stations (CGSs), to prevent natural gas from forming a hydrate in the throttle valve, the natural gas is heated by the heater before reaching the pressure relief valve. Heat exchangers are an essential component of industrial processes that contribute significantly to total system energy. Since the element impacting heat exchanger performance is the fouling process, all fouling processes and models were dynamically simulated in this study. Through coding in the C++ language and simultaneous use of fluent functions, or, in other words, user-defined function (UDF), fouling-related models were defined for this software. The dynamic simulation was performed, and parameters such as fouling strength and layer thickness were calculated. The effects of changing operating conditions, such as gas inlet velocity, surface temperature, and fouling species concentration on fouling growth, were also evaluated. As the concentration of fouling species increased, the fouling rate also increased. The amount of supersaturation and fouling rate increased as the surface temperature increased. Due to the operational limitations of the system, to reduce the fouling rate, the gas inlet velocity should be as high as possible, and the fluid inlet temperature, surface temperature, and concentration of fouling species should be as low as possible. In this study, the required time to reach the efficiency of 70% of the heat exchanger was calculated using the modelling of this chamber, which was equivalent to 190 days. Additionally, the critical thickness of the fouling layer at this time was 3.5 cm.Article Citation - WoS: 2Citation - Scopus: 3Air Density Calculation at High Altitude Locations for Wind Energy Use: the Alpines Validation(Taylor & Francis, 2023) Bingöl, FerhatAtmospheric air density has an essential role in the energy production of wind turbines. It is directly proportional to the power taken out from the airflow. The common practice at a planned wind farm location is to measure atmospheric parameters and calculate the air density as monthly and yearly averages based on the International Committee for Weights and Measures (CIPM). After that, the reference point is used to calibrate spatial data to study the siting of wind turbines at a large spatial domain of interest using an engineering method based on only temperature and elevation a.m.s.l. The engineering method is also employed with only temperature and elevation data when there are no pressure and relative humidity measurements. The point-to-spatial transformation is done through the simplified engineering formula, and it is known that the method is primarily valid up to (Formula presented.) a.m.s.l. Above these elevations, the engineering methods have a significant bias, up to (Formula presented.) error in estimating the air density. This bias leads to a substantial error in energy yield estimations. This study uses more than one in-situ measurement at high altitude locations to calibrate the engineering method at the Alpine Convention Perimeter. It aims to improve the calculation accuracy by calculating the pressure gradient within the region. It is found that the seasonal and yearly averaging errors can be improved by (Formula presented.) to (Formula presented.) in the air density calculation with the new approach. The method can be applied to other locations with similar conditions.Article Citation - WoS: 10Citation - Scopus: 10Hydrogeology and Hydrogeochemistry of the Geothermal Systems and Its Direct Use Application: Balçova-Narlıdere Geothermal System, İzmir, Turkey(Elsevier, 2022) Baba, Alper; Sözbilir, Hasan; Sayık, Tolga; Arslan, Sinan; Uzelli, Taygun; Tonkul, Serhat; Demir, Mustafa MuammerThe Balçova-Narlıdere geothermal system, located in western Turkey, is an extensional domain type geothermal play. Geological, hydrogeological, and geothermal studies have been done in the Balçova-Narlıdere geothermal field since 1960. As a result of these studies, production and research wells were drilled in the area by both the public and private sectors. Of the 37 wells drilled in the Balçova-Narlıdere geothermal field, 26 were drilled by İzmir Geothermal Energy Company Inc. (16 productions, 4 re-injection, 4 gradientst, 2 unused) and 11 by the İzmir Governorship Investment Monitoring and Coordination Department and companies in the private sectors. There are two reservoirs, one shallow and one deep, in the geothermal field. Well depths are less than 200 m in the shallow reservoir. The deep production wells have depths ranging from 400 to 1,100 m and reservoir temperatures reaching 140 °C. The electrical conductivity (EC) values in the shallow production wells range from 1,200 to 1,500 µS/cm. EC values in the deep production wells vary from 1,871 to 2,025 µS/cm, and all geothermal fluids in the field are mineral-rich waters. In the İzmir geothermal district heating system, the newest technologies are used, and operational costs are very low. İzmir Geothermal Energy Company Inc. has been operating since 1996 and has reached 38,460 residences. The current capacity of the system is approximately 160 MWt. Cooling systems continue to spread in Turkey, focusing on electric air conditioning systems and geothermal heating systems, but both economic and applicability problems have slowed the expansion of cooling systems. However, İzmir Geothermal Energy Company Inc. began operating its first geothermal cooling application in Balçova in 2018, cooling 1,900 m2 of the indoor area by lithium bromide absorption and 90/85 °C geothermal temperature regime by supplying 6/9 °C clean cold water to the coolers in the buildings. These results show that the extensional domain type geothermal system in the Balçova-Narlıdere region is suitable for both heating and cooling applications