جستجوی مقالات مرتبط با کلیدواژه « Energy Consumption » در نشریات گروه « مکانیزاسیون کشاورزی »

Drying is one of the most common methods of preserving agricultural products. It is very important to maintain the final quality of the product in the drying process. Changing the temperature parameter and humidity level of dryer air has a great impact on drying time and energy consumption. In this research, to compare the drying speed at different temperatures, a thermal dryer equipped with nano absorbent plates and closed air circulation and energy recovery was evaluated. So that the drying parts included: the product drying chamber, air communication pipes, air blowers, the chamber containing MOF nano absorbent materials, electric air heater and measurement and control systems. Experiments on mint leaves were compared at three temperature levels (40, 50 and 60 ºC) and in two open and closed air circulation methods. The results of the research showed that the drying time decreased with the increase in temperature and the drying time decreased by 50% under the conditions of using nano absorbent plates. Also, the lowest energy consumption was obtained in the conditions of using nano-absorbers at the rate of 161.92 W/h equal to 49% in reducing energy consumption. The changes in the total color index (ΔE) did not change much with the increase in temperature from 40 to 50 ºC, but from 50 to 60 ºC, the total color From 9.22 to 12.86 index increased, but there was not an obvious difference in the total color index between the two methods of using and not using nano absorbents.

This study aimed to investigate the effects of conservation agricultural methods on the amount of soil organic matter, energy indices, and crop yield in white bean (Dorsa variety) cultivation. The experiment was conducted in a randomized complete block design with three replications at the Markazi Agricultural and Natural Resources Research and Education Center in the cropping years of 2017-2018, 2018-2019, and 2019-2020. The experimental treatments were involved: 1- the conventional tillage method (by using moldboard plow+ disc) as a control, 2-Reduced tillage with a chisel-packer plow, and 3-No-tillage method with a direct planting seeder. In each season, the soil organic matter content was measured. The yield and yield components of dry bean seeds were measured at the end of the season by removing the margins. In addition, inputs and outputs energy consumption, gross energy produced per hectare, energy ratio and intensity, and energy productivity were calculated for each treatment. The results showed that the highest and lowest yields were obtained in reduced tillage and no-tillage, respectively, with 2869 and 2076 kg/ha. The three-year average values of soil organic matter in the experimental treatments for each season were 0.430, 0.582, and 0.621%, respectively, with the highest increase seen in reduced tillage treatment. The highest and the lowest energy intensity were obtained for no-tillage and reduced tillage with 38.6 and 27.3 MJ/kg, respectively. One of the reasons for increasing energy consumption and decreasing the yield in the no-tillage method was the high weed population and plentiful consumption of general and specific herbicides. Finally, due to the increase in grain yield, amount of soil organic matter, and improvement of energy indices in dry bean cultivation, the reduced tillage method was evaluated as more suitable than the no-tillage method.

This study investigates the life cycle assessment of cucumber greenhouse production in four cities, Karaj, Hashtgerd, Nazarabad, and Eshtehard, during the crop year 2016-2017, using three energy production systems: conventional (using electricity from fossil fuel sources and diesel for greenhouse heating), photovoltaic, and photovoltaic-thermal. The equivalent amounts of energy consumption were calculated and simulated using TRNSYS software to determine the fuel and electricity requirements of the photovoltaic and photovoltaic-thermal systems. In the next step, IMPACT2002+ method was used to investigate the pollution incidence in the scenarios for cucumber production. The results of life cycle assessments showed that in all photovoltaic system damage categories, the emissions were the least. In addition, the results showed that the total emissions were the highest in the conventional system, followed by the photovoltaic thermal system in the next well. Simulation of solar systems also showed the maximum number of panels needed for photovoltaic and photovoltaic-thermal systems in greenhouse production of 160 and 159 in order to cultivate one ha of cucumber greenhouse production. The life cycle assessment results showed that in all damage categories of the photovoltaic solar system, it has the lowest emission. Also, in the three systems, diesel fuel, photovoltaic and photovoltaic-thermal systems and in parallel with in-field emissions, have the highest share in the injury category emissions. The results showed that the highest level of damage categories, include of human health and ecosystem quality, are 0.005 DALY and 9215 PDF*m2*yr, respectively, in the scenario of energy production using the photovoltaic system and in the damage categories, include of climate change and resource amount of 6629 kg CO2 eq. and 145446 MJ primary were obtained using the conventional energy production system. Results showed that the photovoltaic solar system was the best scenario in all three scenarios.

Providing new solutions to control wet waste is one of the most important issues in maintaining public health. Drying will reduce the harmful effects on the environment by reducing moisture and the smell of wastes as well as easy transportation and disposal costs. The purpose of the design and development of the household dryer is to dry food waste in order to reduce its volume and prevent the spread of its pollution in the air, water, and soil. To study the drying behavior of food waste, an experimental cabinet dryer was designed, fabricated, and evaluated for drying food waste.

The dryer consisted mainly of the drying chamber, electric heater, fan, air inlet channel, mesh tray, air distribution plates, temperature sensor, and control panel. Different parts of the dryer were made of a stainless galvanized sheet. The dryer was modeled using Catia 2019 software and its various parts were designed. The heating power was calculated as 2.7 kW. A centrifugal fan with an air volume of 310 m3h-1, 2800 rpm, and 110 Pa was used to supply airflow in the dryer. In the drying process, a tray with medium and lateral air passage was fabricated and applied. Food waste was obtained from fruit and vegetable waste, homemade food, and fruit shops. And nonfood items such as glass, paper, plastics, and metals were separated from the waste and crushed with a shredder, and reduced to sizes less than 20 mm. First, the product was placed in the environment for one hour and then pressed with a mechanical press with the same pressure to eliminate part of the water. An anemometer UT363 model made in China was used to measure the air velocity. The temperature was measured and controlled by a temperature thermostat of G-sense model made in Iran. The effect of three temperatures of 50, 60, and 70 °C and three inlet velocities of 1, 1.5, and 2 m s-1 on the kinetics and intensity of drying of food waste and energy consumption of food waste with a thickness of 3 cm was investigated. Moisture ratio and drying intensity diagrams were extracted. Diffusion, activation energy, and energy consumption were determined.

Drying kinetics diagrams showed that temperature had a significant effect on moisture variation of food waste during drying. Drying period decreased with increasing temperature. The slope of the drying intensity diagrams increased with the increase of the dryer temperature. Drying rate was decreased at the temperature of 70 °c and it had a steeper slope that indicates the more intensity of the drying process in this condition. The drying process of all three samples occurred in the falling rate stage. The air duct on the side and in the middle of the tray caused hot air conducted above the tray and increased energy consumption. Effective moisture diffusivity of food waste during the drying process was in the range of 3.65×10-9-4.56×10-9 (m2 s-1). The effective moisture diffusivity at temperatures of 50 °C and 60 °C was less than 70 °C. Because at the temperature of 70 °C, the membrane resistance of the cell destroyed by high heat and increased the diffusion coefficient in the material.

Increasing temperature caused the drying period decreased and the drying occurred in the falling rate stage. Temperature and the interaction of velocity and temperature had a significant effect on the drying process. The highest drying intensity and the lowest drying time were observed at the temperature of 70 °C and a velocity of 2 m s-1. Energy consumption had the maximum value at the temperature of 70 °C and a velocity of 2 m s-1 and a minimum value at the temperature of 50 °C and a velocity of 1 ms-1. The amount of activation energy for the food waste mass at three velocities was equal to 10417.44 J mol-1.

Soil-wheel interaction is very attractive topic for agricultural researchers for its effect on the energy consumption and soil properties especially in agriculture. The purpose of this research is measuring soil-wheel contact area under the effect of independent variables of vertical load on the tire, tire inflation pressure and tire forward speed at controlled condition of soil bin also its prediction using adaptive neuro-fuzzy inference system. The tests were accomplished at two forward speeds (0.386 and 0.879 km/h), three inflation pressures (18, 25 and 32 psi), three vertical loads (150, 300 and 450 kg) plus 3 replications and totally 54 passes. All data analysis was done using Genstat software. Results showed that increase of vertical load on the wheel caused to increase of soil-wheel contact area and increment of inflation pressure caused to decrease of it. Low forward speed had not effect on the soil-wheel contact area. Furthermore, correlation coefficient (R2) of ANFIS models (0.9182) was very more than regression one (0.359). Thus, ANFIS models could predict the soil-wheel contact area with high accuracy using measured input variables included vertical load, tire inflation pressure and forward speed at soil bin.

In this study, the energy consumption and environmental effects of pumpkin production in Boroujerd county have been investigated. To evaluate energy in pumpkin production, energy ratio (ER), energy productivity (EP), energy intensity (EI) and net energy gain (NEG) indices were obtained. The values ​​of 1.6, 2.1 kg.MJ-1, 0.4 MJ.kg-1, 10,952 MJ.ha-1 were obtained, respectively. The results showed total input and output energy was 16,191 and 27,143 MJ.ha-1, respectively. Chemical fertilizers and diesel fuel had the highest energy consumption among the inputs. Environmental effects were assessed with a life cycle approach using the CML model. Nitrogen fertilizer with 48% in acidification and pesticides with 90% in global warming accounted for the highest share of these impact categories. It is suggested that the use of fertilizers and chemical pesticides be managed by educating farmers to save energy, economic and environmental benefits.

In this research, the adaptive neuro-fuzzy inference system was used for predicting the imposed forces on the tines and tractor fuel consumption during subsoiling operation. The draft and vertical forces imposed on subsoiling tines and tractor fuel consumption were measured under the effect of tine type (subsoiler and paraplow), tillage depth (30, 40 and 50 cm) and forward speed (1.8, 2.3, 2.9 and 3.5 km/h). The field data were used to create the regression and ANFIS models for predicting the studied parameters; the results obtained from applying two models were compared with each other. The field results showed that all independent variables were effective on the studied parameters. Increase in forward speed and tillage depth resulted increase in draft force, vertical forces, and also fuel consumption. Moreover, from the point of consumption of fuel, the paraplow tine was more profitable than subsoiler tine. The results of ANFIS part showed that draft force, vertical force, and fuel consumption, the membership functions of Gaussmf, Trimf and dsigmf, with the mean square error of 0.0156, 0.0231 and 0.0212 also correlation coefficient of 0.999, 0.989 and 0.991, respectively, were the best models for prediction. ANFIS models were found more accurate than regression models, and it could be possible to calculate the model outlet for a special inlet using ANFIS outlet surfaces.

The aviculture industry is very important in terms of the protein requirements of the country. In this research, the energy efficiency and Greenhouse gas emissions of broiler chickens breeding centers in Kermanshah province was investigated. The total average input energy was 269242.84MJ, and the average total output energy was 30513.67 MJ Fuel (natural gas and gasoline) and feed with 46.82% and 28.36%, had the highest rate of energy consumption. The studied energy indexes were included in the energy ratio, energy efficiency, energy intensity, net energy added and respectively with 0.11, 0.01 kg /MJ, 48.16 MJ/kg, -1260369 MJ. To increase the energy efficiency index and the positive net energy value added, it is possible to reduce the amount of energy consumed by the correct management of high inputs and the use of renewable energies. Based on the obtained results using the Cobb-Douglas function, the coefficients of the inputs indicated that the stretch of the inputs include chicken, gas, manpower, corn, soybeans, minerals, fatty acid, calcium phosphate, water, and the disinfection was positive and smaller than one and their MP value was less than AP, so the use of these inputs by economic operators of poultry units of the region was economic and in the second area of production function were placed. The total emissions of greenhouse gases were equal to 2562.49 kg CO2eq, which the highest contribution was for fed with 37.12% and fuel and electricity 34.22 and 28.32 (kg CO2eq), respectively. The aviculture industry is very important in terms of the protein requirements of the country. In this research, the energy efficiency and Greenhouse gas emissions of broiler chickens breeding centers in Kermanshah province was investigated. The total average input energy was 269242.84MJ, and the average The aviculture industry is very important in terms of the protein requirements of the country. In this research, the energy efficiency and Greenhouse gas emissions of broiler chickens breeding centers in

According to technology progress and the increase in human populations since the Industrial Revolution, the amount of waste generated is increasing. With the increase in waste production, due to problems and challenges such as emissions from waste, require to sustainable management of waste has increased. One of the methods of waste management is to use it for the production of compost. In this study, the composting plant in Rasht was investigated, with a daily input of around 400 ton of MSW. Of this 400 ton of waste, 64.1 percent is the organic material, that 48 percent (192 ton) after the processing is separated from the MSW and sent to the fermentation location, and finally 12 ton compost is produced. The amount of energy consumed at this plant, after calculating the input and output energy, was about 82.02 GJ. Energy productivity index was calculated as 0.15 ton/GJ. Environmental ECO-costs for the entire composting process were obtained as 4.92×107 Rial.

This study was carried out to determine energy consumption in various stages of processing of black tea in tea factories at Guilan province in Iran. Direct energy (thermal energy and electric energy) and indirect energy (man power, depreciation, and lubricants) were measured and evaluated in 9 tea factories; four factories using diesel fuel and the remaining five used natural gas. The results showed that approximately 70 percent of the energy consumed in tea processing is thermal energy of which 31 percent used in withering and remaining 69 percent used in drying stage. The amount of thermal energy consumed in tea factories with natural gas fuel is about 5 percent less than that in factories used diesel fuel. Electric energy has contributed 28 percent of total energy consumed in production of black tea. Withering, rolling and air heaters used 58.16, 16.58 and 11.39 percent of energy consumption in tea factories, respectively. Man power has contributed the lowest percentage of energy consumption in tea processing. Inappropriate designing, burnout ovens, lack of proper insulation, and improper structures of mechanical parts are responsible for significant energy losses at tea factories. The following steps could help reducing energy consumption in tea processing: installation of new designed furnaces, insulation the present furnaces and drying machines, and improving power supplying systems.

Application of minimum and no- tillage operation not only increase soil organic mater and soil fertility, but also decreases the production cost and energy consumption in wheat production. In order to evaluate the effect of tillage methods on amount of input and output energy as well energy indices and grain yield in wheat-corn rotation, a randomize complete block designe experiment (RCBD) with three replications comprising of four tratments was conducted during 2012-2013 and 2013-2014 at Research Farm of Agricultural and Natural Resources Research and Training Center of Markazi Province. Treatments were: Moldboard plow and disk as prevailing tillage method, Minimum tillage by chisel plow, Minimum tillage by combined plow and No-tillage. During course of investigation fuel consumption, consumed energy for all inputs, output energy as well as energy indices were measured. Results showed that the effect of tillage methods was not significant on yield (p<0.05). Fuel consumption in first, second, thirs and fourth treatments were 80.46, 31.46, 33 and 14/5 L/ha respectively. The highest and the lowest energy pruductivity was that of no-tillage and conventional metod with 0.075 and 0.062 Mega joule per kilogram of crop harvested. Energy consumption in conventional, chisel plow, Combined Plow and No-tillage treatments were 57670, 50849, 50949 and 47609 Mj respectively. Considering the energy indices, best treatment, was related to no-tillage method.

With the development of modern drying paddy in addition to speed up the drying process, and in particular the amount of waste can be reduced to the minimum possible energy consumption. In this study was investigate the effect of input air temperature, input air flow rate and variety also their interaction on energy consumption and drying rate in the fluidized bed dryer. The parameters of input air temperature at 4 levels of 45, 50, 55 and 60 °C, the air flow rate at 3 levels of 0/12, 0/14 and 0/16 m3/s and variety of paddy at 3 levels Tarom, Fajr and Shirudi was considered and tests was done in three replication in form of a 3×3×4 the 3-factor factorial design. The results indicated that In all three varieties tested, by increasing the intake air temperature as well as reduced energy consumption, drying rate also increased significantly. At 45 and 50 ° C, increasing air flow grain drying had no significant effect on the rate But at 55 and 60 ° C by increasing the flow rate of drying significantly increased. The results showed that by increasing air flow, increased energy consumption.

Greenhouse is a structure which provides the best condition for the maximum plants growth during the cold seasons. In cold climate zones such as Tabriz province, Iran, the greenhouse heating is one of the most energy consumers. It has been estimated that the greenhouse heating cost is attributed up to 30% of the total operational costs of the greenhouses. Renewable energy resources are clean alternatives that can be used in greenhouse heating. Among the renewable energy resources, solar energy has the highest potential around the world. In this regard, application of solar energy in greenhouse heating during the cold months of a year could be considerable. The rate of thermal energy required inside the greenhouse depends on the solar radiation received inside the greenhouse. Using a north brick wall in an east-west oriented greenhouse can increase the absorption of solar radiation and consequently reduces the thermal and radiation losses. Therefore, the main objective of the present study is to investigate the effect of implementing of a north wall on the solar radiation absorption and energy consumption of an east-west oriented single span greenhouse in Tabriz.
This study was carried out in Tabriz and a steady state analysis was used to predict the energy consumption of a single span greenhouse. For this purpose, thermal energy balance equations for different components of the greenhouse including the soil layer, internal air and plants were presented. For investigating the effect of the north wall on the energy consumption, the Ft and Fn parameters were used to calculate the radiation loss from the walls of the greenhouses. These factors were determined using a 3D–shadow analysis by Auto–CAD software. An east-west oriented single span greenhouse which has a north brick wall and is covered with a single glass sheet with 4 mm thickness was applied to validate the developed models. The measurements were carried out on a sunny winter day (November 30, 2015). The hourly variations of solar radiation on a horizontal surface were measured to calculate the total solar radiation received by the greenhouse using the Liu and Jordan equations. For heating of a greenhouse in nighttime, an electrical heater was used while an additional required energy was measured using a single phase meters. The inside and ambient temperatures of the air were recorded using SHT11 temperature sensors. A computer-based program of EES (engineering equations solver) was developed to solve the energy balance equations. Different statistical indicators were used to predict the accuracy of the presented models.
The obtained results showed that in winter months the greenhouse without the north brick wall can receive 14% more solar radiation than the greenhouse with a north brick wall. On the other hand, the use of a north wall in the greenhouses can reduce the radiation and thermal loss from north wall. To maintain the temperature at 25 °C in day-time and 15 °C in night-time, the additional required energy was calculated for greenhouse with and without north brick wall. The results indicated that the total energy requirement to keep the plants warm was 313.8 MJ in greenhouse without north brick wall and 210.8 MJ in greenhouse with the north brick wall. In other word, use of the north brick wall in the greenhouse can contribute to reduce energy consumption by 32%. Comparisons between the predicted and measured results showed a fair agreement for greenhouse energy requirements. The correlation coefficient and mean percentage error for this model were determined to be 0.79 and -2.34%, respectively. Due to the small values, the radiative exchange within greenhouse cover and the sky was neglected. Therefore, the results of the presented model showed fewer values in comparison with the experimental results. It can be concluded from the final results that a considerable amount of the incident radiation has been lost to the ambient by convection from the cover of the greenhouse (glass walls and north walls).
In the present study, the effect of north brick wall on solar radiation absorption and energy consumption of a single span greenhouse located in Tabriz was investigated. Results showed that use of north brick wall in an east-west oriented single span greenhouse leads to a reduction of 14% in solar radiation absorbed by the greenhouse. The results indicated that use of the north brick wall in the greenhouse can decrease energy consumption by 32%. There was a fair agreement between the experimental and theoretical results with the calculated correlation coefficient and mean percentage error of 0.79 and -2.34%, respectively.

A mixed solar dryer with a specific mechanism to vary the tilted angle of collector، is utilized to fulfill all tests. The efficiency of the dryers is low because of various reasons such as heat loss of air in an open flow circuit. Getting air back toward the air inlet of dryer can increase the efficiency of dryer and decrease drying process period. A new mechanism considered for dryer which controls the percentage of air recirculation. It contains two dampers which embedded in return air channel of dryer. In order to investigate the effect of air recirculation on energy consumption of drying and dryer efficiency، thin layer of tomato slices are dried in three levels of air flow rate (0. 018، 0. 036 and 0. 054 m3/s) and four levels of air recirculation percentage (0، 50، 75 and 87. 5%). Total experiments were achieved in the beginning of autumn season to reach the moisture content of 12% (w. b) of the samples. The results illustrated the minimum of energy consumption and the maximum of efficiency was provided when 75% of air flow was got back to the inlet of dryer.

In this study thin layer drying of corn in a convective dryer was investigated at air temperatures of 50، 60 and 70ºC and air flow rates of 1، 1. 4 and 1. 8 kg min-1. Experiments were performed in Completely Randomized Design (CRD). The effect of air temperature and flow rate on drying time، drying rate، effective diffusivity coefficient and activation energy were studied. Results showed that the effects of temperature and flow rate on drying process were significant. Increasing the air temperature from 50 to 70 C˚، caused 31. 7 percent decrease in drying time and change of air flow rate from 1 to 1. 8 kg min-1 reduced drying time 27 percent in average. The effective diffusivity coefficient and activation energy varied from 3. 47258 ×10-11 to 7. 34352×10-11 m2 s-1. and 13. 761 to 16. 193 kJ mol-1، respectively depending on the drying treatments. The Logarithmic model was found to be in a better agreement with experimental data compared with other models. The minimum value of specific energy requirement (3. 61 kWh kg-1) was obtained at a drying air temperature of 50 °C and air flow rate of 1 kg min-1، whereas the corresponding parameters for the maximum value (5. 34 kWh kg-1) were determined as 70 °C and air flow rate 1. 8 kg min-1.

By increasing crops yield due to intensive use of agricultural machinery and energy inputs، utilized energy in agriculture has been increasing rapidly which negative environmental impacts on water، air and soil are its consequences. In this paper، potato production in Isfahan province was studied using life cycle assessment approach from the standpoint of energy consumption and environmental impacts. Functional unit and system boundary were determined to be one hectare and the farm gate، respectively. Moreover، the environmental impacts of inputs application rate were interpreted in three impact categories: global warming potential، human toxicity and eutrophication. Results revealed that the highest proportion of energy consumption belonged to electricity. In addition، chemical fertilizers and diesel fuel showed the greatest impact on global warming potential and eutrophication. However، Pesticides had insignificant contribution to the total energy input; they had the greatest effect on human toxicity with a share of 70%. Among the emissions of chemical fertilizers، N2O had the highest impact with a share of 97% on global warming potential. Phosphate and Diazinon played an important role with 68% (each one) in the impact categories of eutrophication and human toxicity respectively.