Ships are complex energy plants which are equipped with several energy producing and consuming machineries. Almost all of the ships have main and auxiliary engines consuming fossil fuels to meet the power demands of all ship operations including propulsion, heating, cooling, pumping etc. All types of energy losses on board caused by different sources such as hull friction, air draft of ship, heat losses, pressure losses of fittings and pipes and engines energy losses are determined and additional power requirements of engines are specified to compensate these losses. The optimum design and operational criteria are discussed to decrease total energy loses. Furthermore, the costs of fuel price and environmental damages due to exhaust gas emissions are specified by reason of additional fuel consumptions.

The effect of phase change material (PCM) integration in building components is investigated in mild climates. The incorporation of PCMs in building materials is particularly interesting since it permit to the thermal storage to become a part of the building structure and is completely passive. Simulations in a typical family house were made and the contribution of PCMs on different buildings components was analyzed. Results show important reduction in cooling energy even in those climates characterized by low day/night temperature swings. Even if large quantities of PCM are necessary, a reduction of 20% can be obtained with reasonable thickness of PCM wallboards. The best position for PCMs is found to be on surfaces that undergo large temperature variations (connected to the outdoor air) like the ceiling for example. This position present the better compromise between energy reduction and PCM quantity used.

In this paper, a forced circulation solar water heater (SWH) has been studied both experimentally and numerically. Outdoor condition is based on ambient climate of Tabriz. Flat plate collector was kept facing the equator at a tilt of λ+15° (λ is latitude of the place and λ=38.7 N for Tabriz) from the horizontal for getting maximum radiation. The Investigated system is consisted of a collector with total absorber area of 1.82 (m²), a storage tank of 60 (liter) capacity, 12 tubes and an overhead tank placed at a higher level respect to the rest of the system. Also, a numerical model was developed to simulation of SWH. To discrete equations, finite volume method is employed. In addition, a numerical model of SWH with elliptical tubes was developed and results show that there is no significant difference in heat transfer rate between circular and elliptical tubes. Two major circumstances were investigated in this study namely parallel and series coupling of collectors. Finally, the simulation outcomes are compared with the experimental data and differences between numerical and experimental results have been reported.