Dogan Eryener

Exergoeconomic analysis of condenser type heat exchangers

In this study, an exergoeconomic analysis of condenser type parallel flow heat exchangers is presented. Exergy losses of the heat exchanger and investment and operation expenses related to this are determined with functions of steam mass flow rate and water exit temperature at constant values of thermal power of the heat exchanger at 75240 W, cold water mass flow rate and temperature. The inlet temperature of water is 18 °C and exit temperatures of water are varied from 25 °C to 36 °C. The values of temperature and pressure of saturated steam in the condenser are given to be Tcon=47 ° C and Pcon=10.53 kPa. Constant environment conditions are assumed. Annual operation hour and unit price of electrical energy are taken into account for determination of the annual operation expenses. Investment expenses are obtained according to the variation of heat capacity rate and logarithmic mean temperature difference and also heat exchanger dimension determined for each situation. The present analysis is hoped to be useful in determining the effective parameters for the most appropriate exergy losses together with operating conditions and in finding the optimum working points for the condenser type heat exchangers.

Experimental Studies on Influence of Process Variables to the Exergy Losses at the Double Tube Heat Exchanger

Heat Exchangers are widely used at different applications related with heat science and techniques. Today at the investigation of heat exchanger projection, First Low of Thermodynamics is not anymore sufficient. The reason of this more effective use of heating sources and systems, not the quantity of energy but quality of energy must be taken into consideration. Energy transformation in the heat exchangers, in the scope of Second Law of Thermodynamics can be listed in two groups depending on chosen variables for analysis. These are a) entropy based work b) exergy based work. In this study, it is aimed to analysed theoretically and investigate experimentally effect of inlet and outlet temperatures of temperatures differences and flow directions for same path parallel flow and counter path parallel flow by using double tube heat exchanger. According to the obtained results, it is aimed to detennine necessary information for projection and to bring down to the most economical value of the heat exchanger cost and of energy consumption.

Endüstriyel Tesisler için Güneş Duvarı Performansının İncelenmesi

Bu calismada, Turkiye’de uygulamasi yapilan ilk hava sizdirmali gunes duvarin saha performansinin analizi yapilmistir. 2012 yilinda Cayirova-Kocaeli’nde bir otomotiv tesisinde isitma ve havalandirma amacli olarak uygulamasi yapilan 770 m2 ’lik gunes duvarinin performansi, iki yillik bir sure zarfinda kis donemlerde ucer aylik periyodlar halinde bina yonetim sistemi vasitasiyla incelenmistir. Ayrica, sistemin teorik analizi, bir gunes duvari simulasyon yazilimi kullanilarak yapilmis ve elde edilen sonuclar saha verileri ile karsilastirilmistir. Simulasyon sonuclarina benzer olarak, 2013 yilinda 113,037 kWh enerji, 2014 yilindaki 246,924 kWh isi enerjisi uretmis ve donemsel olarak %62 varan bir enerji tasarruf elde edilmistir.