Sürdürülebilir Kalkınma Amaçları
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- 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 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.