ملخص البحث :

The response surface methodology (RSM) is used in the present research together with a group of variables that have an effect on engine performance and output exhaust from the combustion process. Therefore, the purpose of the current paper is to get efficiency best by using biodiesel fuel and comparative with normal fuel. The variables under consideration include biodiesel ratio, engine load, and injection pressure. The experiments were performed with different engine speeds (1500, 2000, and 2500 rpm) and with different torques (4, 5, 5, 7, and 8 N.m). The biodiesel ratio (at 10%, 20%, and 30%) affects engine performance, power, specific fuel consumption, and mean effective pressure. The comparison is performed in the previous variables according to the gas ratio of the output exhaust (NOX, CO2, CO, HC, and smoke). The experimental work shows the center composite design approach of the response surface methodology. To get the best performance from the engine, the optimal values for the engine factors are 50% per volume, an engine speed of 2500 rpm, and an engine torque of 5.9744 Nm. The optimal engine performance responses depending on these optimal factors have been Power (KW) 2.36665, BMEB (bar) 3.6465, BSFC (g/kWh) 338.131. The exhaust released was 1.7808 (g/kWh). 273.985 (g/kWh) BSCO2, 0.0436773 (g/kWh) BSCO BSHC, NOX (2.48637 g/kWh), and 3.43418 g/kWh smoke.

ملخص البحث :

AbstractIn this study, the melting processes of PCM in a circular shell and rectangular tube heat exchanger by using solar thermal energy have been studied experimentally to evaluate thermal storage performance of PCM. All experimental were conducted outdoor at AL- Musayyib city-Babylon-Iraq. In this study two different types of Paraffin are tested; PCM1 (which is produced in Iraq) and PCM2 which is produced in Germany. The main experimental procedure in the present work is included using the solar collector type of evacuated tube for melting PCM in shell regime. Different volume flow rates of the water flow within the inner tube of the heat exchanger namely (200, 300, and 500 lph) were used for each season from August 2016 to January 2017. The experimental results indicated that inlet temperature of the inner tube and ambient temperature has significant effects on the melting point compared with the volume flow rates. Studying PCM temperature distribution, it is exposed that a melting temperatures of the PCM in summer season needed time of (3-4) hours only, while it needed more time; about (14-16) hours in winter season. Increasing the ambient temperature and the solar radiation reduces the melting time for both PCM types. Increasing water temperature difference of inner tube increased the heat gained for PCM.The present experimental results compared with the available previous studied and give a good agreement.