In this research between 3-dimensional and axisymmetric modeling for movement of nano-particles in passing through a aerodynamic lens, and also between these models and famous model of Wang & Liu was compared. For this purpose, output of nano-particles penetration, divergence angel, and nano-particle velocity with Wang & Liu model was compared. Geometrical model used for aerodynamic lens compared to past research is more complete and has been selected based on practical model. With regard to low density of nano-particles, hypothesis of one way interaction between liquid and molecule has been selected. That is, movement of nano-particles does not have any effect upon flowing field. Trajectory of nano-particles with diameters of 1, 2, 6, 10, 30 and 50 were investigated. Cumulative fraction of radial that shows the amount of nano-particles divergence compared to axial system for diameters of 2, 6, 10, 20, and 30 were calculated in both three dimensional model and symmetrical model and compared with Wang & Liu model. Results are shownd that nano-particles with lower diameter because of more influence from outside power become farther and this matter create difference between results of two model, since in three dimensional model, nano-particles are affected in three ways by this power. These resultd show that axisymmetric modeling in nano-particles movement is not accurate and exact. Also, there is a good conformity between applied model and Wang & Liu model. تفاصيل المقالة

The most widespread application of renewable energy is heat production, mainly related to biofuels and solar water heaters (SWHs). Considering that SWHs are essential in energy supply, the present work aims to investigate the heat requirement of a residential apartment in Pakistan using a radiator system in 32 investigated stations. The daily water requirement is 160 L, and the ideal water temperature is 50 oC. It should be considered that hot sanitary water is needed for all 365 days. The investigations were carried out with TSOL Pro 5.5 software to simulate the heat of the desired locations. Also, after the analysis, we found that the selected location's SWH and thermal energy supply have high efficiency. The total heat supply using renewable energies is 18-42% for the investigated stations, and the rest of the required heat is supplied with fossil fuel. Since SWHs are one of the simplest and most economical ways to provide hot water for homes, offices, schools, hospitals, etc., Pakistani people can save a large amount of energy by investing in this field. Considering that Pakistan has good radiation potential, we hope that the present work results will lead to more use of SWHs. تفاصيل المقالة

The most widespread use of solar energy as an alternative to fossil fuels is for heating. Considering the location of Iran and its location on the global Sunbelt, the aim of the present work is to provide part of the heat needed for the treatment space of Seyed Al-Shohda hospital in Yazd by using a flat plate solar collectors system. A one-year dynamic simulation has been performed using TSOL Pro 5.5 software, and energy-environmental-economic (3E) analyzes have been performed on the proposed system. The difference between the present work and the past works is that the provision of space heating and sanitary spa needed for a treatment space has not been done yet. The results of the investigations showed that about 2MWh of solar heat is produced, which prevents the annual release of about 630kg of CO2 pollutants. Examining the system loss diagram also shows that the bottleneck of energy loss in the system under review is the hot water storage tanks, which have an annual energy loss of about 800 kWh. Financial analysis showed that the price of each kWh of solar heat production and the internal rate of return (IRR) are 0.0021 euros and 2.23%, respectively. The results of the present work indicate the excellent potential of Yazd in the field of using solar water heaters (SWH) for heating treatment spaces. The results of the present work can be used as a roadmap to help energy decision-makers and investors in this sector and accelerate the development of SWHs. تفاصيل المقالة