Renewable Energy Resources and Technologies
Hemad Zareiforoush; Adel Bakhshipour; Iraj Bagheri
Abstract
Drying process is an important post-harvest stage of food crops production which accounts for about 20 % of the world’s energy consumption in the industrial sector. One of the effective ways to reduce the share of fossil fuel consumption in the food drying process is to develop new drying systems ...
Read More
Drying process is an important post-harvest stage of food crops production which accounts for about 20 % of the world’s energy consumption in the industrial sector. One of the effective ways to reduce the share of fossil fuel consumption in the food drying process is to develop new drying systems based on the use of renewable energy sources. In this research, a novel solar-assisted multi-belt conveyor dryer was developed and its performance was analysed. The required thermal energy for drying process was supplied by the combination of solar-gas water heaters and four solar-powered infrared (IR) lamps. The experimental factors included the speed and temperature of the drying air and the power of IR lamps. The performance characteristics were drying time, Overall Specific Energy (OSE), Non-Solar Specific Energy (NSE), Overall Energy Efficiency (OEE), and Solar-Assisted Energy Efficiency (SEE). The optimization process of the drying system was carried out using Response Surface Methodology (RSM) by defining two general modes for the energy sources of the drying system, namely overall mode and solar-assisted mode. Based on the results, the lowest OSE (17.30 MJ/kg water evaporated) was obtained when the speed and temperature of the drying air were equal to 7 m/s and 40 °C, respectively, without using IR power. The lowest NSE (2.71 MJ/kg water evaporated) was achieved by applying the treatment of 7 m/s * 40 °C * 300 W. The maximum OEE was equal to 13.92 % whilst the maximum SEE was obtained as 88.71 %. Both of the mentioned maximum values were obtained at the speed and temperature combination of 7 m/s and 40 °C and their difference was applying 300 W IR power to gain maximum SEE and no IR utilization for the maximum OEE. According to RSM analysis, the optimum working conditions for the drying system included the treatment of 7 m/s * 39.96 ºC * 300 W. Under this condition, the drying time, NSE, and SEE values were equal to 180.95 min, 1.062 MJ/kg water evaporated, and 84.63 %, respectively.
Renewable Energy Economics, Policies and Planning
Mohammad Ameri; Arian Gerami
Abstract
According to the previous pieces of research, the building sector consumes about 40 % of total yield energy and produce one-third of GHG pollution emission. This point shows the significant potential in two aspects of energy optimization and pollution reduction in this field. The purpose of this research ...
Read More
According to the previous pieces of research, the building sector consumes about 40 % of total yield energy and produce one-third of GHG pollution emission. This point shows the significant potential in two aspects of energy optimization and pollution reduction in this field. The purpose of this research as a case study is to construct a residential building and develop the paths for reaching a zero-energy building, considering GHG emissions in the climate of Tehran, Iran. In thirty scenarios of this study, solar panels, solar water heaters, ground source heat pumps, and combined heat and power generators were selected to provide the required power and energy in the building. All three passive, single active, and hybrid active scenarios were defined and analyzed with respect to technical and economic factors. In all of the defined scenarios, the conditions are two-folded: (a) considering the effect of national profits, fuel saving, and pollution reduction and (b) without considering them so that the results would become more realistic. In the end, three different types of conclusions were made with respect to macro-engineering, energy, and economic perspectives. Statistical conclusions based on a questionnaire filled by 50 people and the perspective of achieving NZEB definition are presented.
Renewable Energy Resources and Technologies
Mehdi Jahangiri; Akbar Alidadi Shamsabadi; Hamed Saghaei
Abstract
Canadian researchers are now trying to exploit much more energy from solar sources, hydropower, wind, and biomass. Given the fact that reducing the carbon pollutant level is a political priority in Canada, this paper studies the feasibility of providing sanitary hot water and space heating demands of ...
Read More
Canadian researchers are now trying to exploit much more energy from solar sources, hydropower, wind, and biomass. Given the fact that reducing the carbon pollutant level is a political priority in Canada, this paper studies the feasibility of providing sanitary hot water and space heating demands of a four-member family in 10 provinces in this country. The feasibility analysis was performed by T*SOL Pro 5.5 software, and radiation data were obtained by MeteoSyn software. Results indicated that the most suitable station in terms of using solar water heater was Regina, which supplied 35 % of the total heat load for space heating and sanitary hot water purposes. This accounted for 5074 kWh of heat for space heating (25 % of demand) and 3112 kWh energy for sanitary hot water (94 % of demand) using a 40 m2 solar collector. In addition, results are indicative of an annual amount of saving up to 2080 kg of CO2 in the Regina station and an annual reduction of 984 m3 in natural gas for this station. In conclusion, Canada has a potentially alluring market to utilize solar water heaters for providing sanitary hot water for the residential sector.
Abbas Rajabi Khanghahi; Mohammad Zamen; Mehdi Soufari; Majid Amidpour; Ali Abbas Nejad
Abstract
One of the subjects in solar water heater design is considering distribution of hot water consumption during the day. For example, each of the household, commercial, office, school, and industrial consumptions have a particular distribution of hot water consumption named pattern in this article. In solar ...
Read More
One of the subjects in solar water heater design is considering distribution of hot water consumption during the day. For example, each of the household, commercial, office, school, and industrial consumptions have a particular distribution of hot water consumption named pattern in this article. In solar computation principles, the effect of longitude, latitude, and altitude on collector angle has been clearly presented. However, the effect of consumption pattern especially on the collector orientation has been rarely investigated. The aim of the current study is to survey the effect of various consumption patterns on the collector’s orientation and tilt angle and so calculation of related energy saving. So, five common patterns including office building, commercial building, afternoon and morning shift high school and a 15-unit apartment have been studied and optimal surface azimuth angle and tilt angle determined. It has been observed that 11 to 14 % energy saving can be archived by selecting the optimal angles with respect to hot water consumption pattern in comparison to a state that collectors are orientated for maximum reception of solar energy. Also effect of solar fraction, storage volume and amount of hot water consumption are studied and discussed.
