Sharif Digital Repository

This paper addresses a low complexity and high efficient cooling system applicable on photovoltaic (PV) system leading to enhance electrical efficiency and provide preheated water. The developed system consists of a photovoltaic panel, a cooling water system establishing a uniform surface temperature, and a solar water heater. According to the proposed system characteristics, the setup is constructed based on a single mono-crystalline solar panel to absorb more solar radiation intensity and generate more electrical energy per area in compare to a poly-crystalline panel. The preheated water produced by absorbed heat from the photovoltaic is conducted to a solar water heater to satisfy... 

This paper addresses a low complexity and high efficient cooling system applicable on photovoltaic (PV) system leading to enhance electrical efficiency and provide preheated water. The developed system consists of a photovoltaic panel, a cooling water system establishing a uniform surface temperature, and a solar water heater. According to the proposed system characteristics, the setup is constructed based on a single mono-crystalline solar panel to absorb more solar radiation intensity and generate more electrical energy per area in compare to a poly-crystalline panel. The preheated water produced by absorbed heat from the photovoltaic is conducted to a solar water heater to satisfy... 

Transcritical-CO2, supercritical-CO2, and organic Rankine cycles are numerically investigated and compared in simple Rankine, Rankine with internal heat exchanger, and regenerative Rankine configurations to assess their thermodynamic and thermoeconomic performance indicators. Subsequently, the systems are optimized using a multi-objective optimization method. Pareto optimal solutions are provided to present the trade-off between thermodynamic and thermoeconomic indicators. In addition, scatter plots of decision variables are presented to ascertain the optimal operating range of input variables. The results show that transcritical-CO2 systems can generate the highest power. The levelized cost... 

Ground-coupled ejector cooling (GCEC) systems have been introduced to solve the air-coupled ejector cooling (ACEC) systems problems. To date, no research study is dedicated to compare the GCEC and the ACEC systems and determine the relative payback period of the GCEC system vs. the ACEC system. Furthermore, almost all the previous studies simulated the GCEC systems by elementary models. Therefore, a comprehensive simulation is conducted to assess the techno-economic performance of a GCEC system. The model consists of the ejector and the borehole heat exchanger submodels. The first section of the results compares the ACEC system and the GCEC system during a cooling season. The seasonal... 

In this study, the prospects of energy efficiency potential, clean development mechanism (CDM) and carbon income up to and beyond 2012 are investigated in the petrochemical industries of Iran as a major oil-producing country. This paper is to address four questions of: (1) the GHGs emission in Iranian petrochemical complexes, (2) the most energy-consuming processes, (3) units with the highest energy efficiency potentials and (4) potentials of CDM or similar carbon projects based on post-2012 scenarios. The petrochemical processes are investigated in two categories of non-polymeric and polymeric productions. Based on capital expenditure, economic saving, simple payback period, CO2 equivalent... 

To mitigate global warming and fossil fuel shortages a novel oxy-fuel combustion power plant integrated with a power to gas system is proposed. A net-zero emission MATIANT cycle with inherent CO2 capture ability is selected as the power cycle also providing the CO2 and power demand of the power to gas system, which comprises a proton exchange membrane electrolyzer for hydrogen production and a Sabatier reactor for methanation. A techno-economic investigation, a multi-objective optimization, and a sensitivity analysis are carried out. A comprehensive economic method that covers all economic aspects is utilized, and a Sabatier reactor model which considers the possibility of the presence of... 

Hydrogen as an energy carrier can play a significant role in reducing environmental emissions if it is produced from renewable energy resources. This research aims to assess hydrogen production from wind energy considering environmental, economic, and technical aspect for the East Azerbaijan province of Iran. The economic assessment is performed by calculation of payback period, levelized cost of hydrogen, and levelized cost of electricity. Since uncertainty in the power output of wind turbines may affect the payback period, all calculations are performed for four different turbine degradation rates. While it is common in the literature to choose the wind turbine based on a single criterion,...