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The paper brings new evidence on the impact of separate mechanical ventilation system on the annual energy and exergy performance of several design alternatives of residential heating systems, when they are designed for a house in Montreal. Mathematical models of residential heating, ventilation and domestic hot water (HVAC–DHW) systems, which are needed for this purpose, are developed and furthermore...
The objective of this study was to examine the energy use patterns and cost of production in greenhouse and open-field grape production. Data used in the study were obtained from the experiment conducted at the Akdeniz university research field. In the study, energy values were calculated by multiplying the amount of inputs and outputs by the related energy conversion factors. The results indicated...
Ethanol production from cellulosic sources such as switchgrass (Panicum virgatum L.) requires the use of natural resources, fossil fuels, electricity, and human-derived goods and services. We used emergy accounting to integrate the ultimate amount of environmental, fossil fuel, and human-derived energy required to produce ethanol from switchgrass. Emergy is the total amount of energy of one form required...
An ‘integrated appraisal’ of a solar hot water (SHW) system in the UK residential sector was carried out to assess its overall energetic, environmental and economic performance. The energy analysis indicates that when displacing a gas boiler, oil boiler, or electrical immersion heater, the SHW system would provide a net energy benefit for the majority of its estimated 25year lifetime, thus enhancing...
This paper is concerned with the energy and exergy analyses of the thin layer drying process of mulberry via forced solar dryer. Using the first law of thermodynamics, energy analysis was carried out to estimate the ratios of energy utilization and the amounts of energy gain from the solar air collector. However, exergy analysis was accomplished to determine exergy losses during the drying process...
In this paper, we deal with the energy and exergy analysis of a fossil plant and ground and air source heat pump building heating system at two different dead-state temperatures. A zone model of a building with natural ventilation is considered and heat is being supplied by condensing boiler. The same zone model is applied for heat pump building heating system. Since energy and exergy demand are key...
The demand on primary energy resources of three steelmaking technologies has been evaluated using an integrated energy analysis approach that takes into account the energy equivalent of major materials and supplies used in the process, as well as the inefficiency of electricity generation. Two new parameters, Material CO 2 Footprint (MCF) and Process CO 2 Footprint (PCF), are defined...
A heat pump system is the ideal way to extend the heat supply of existing oil or gas fired heating system. Consumption costs are lowered through the use of free energy from the environment, and the dependence on fossils fuels simultaneously reduces. In order to investigate the performance of the solar-ground source heat pump system in the province of Erzurum having cold climate, an experimental set-up...
Energy efficiency of agriculture needs improvement to reduce the dependency on non-renewable energy sources. We estimated the energy flows of a wheat–maize–soybean–maize rotation of three different cropping systems: (i) low-input integrated farming (LI), (ii) integrated farming following European Regulations (IFS), and (iii) conventional farming (CONV). Balancing N fertilization with actual crop requirements...
This study develops a novel approach to predict the outdoor temperature fluctuations during daytime as a dimensionless temperature variation coefficient. In this approach, the daily outdoor temperature trend is established by using the daily maximum and minimum temperatures. A case study is performed to calculate the cooling degree-hours for 58 cities in different geographical regions of Turkey as...
This study evaluated the energy balance and economic analysis between inputs and output of seed corn production in different harvesting systems in Iran. Data were collected from seed corn farms in Alborz province. The results indicated the total average energy input and output of 51.1 and 243.9GJha −1 , respectively. The highest share in energy consumption belonged to chemical fertilizers...
Thermo-compressors are widely used in industries for steam compression through a thermal process. Common methods of thermo-compressors analysis are based on the hypothesis of considering steam as a perfect gas. In this study, the deviation of thermo-compressor performance at wet steam conditions from the performance under the ideal gas assumption has been investigated. Firstly, a numerical method...
This paper estimates energy consumption per unit floor area of greenhouse and open field for tomato, chili and lettuce production. Primary data were collected from 530 vegetable farmers during Jan–Dec, 2010 in West Java, Indonesia. Energy estimates were calculated from actual amount of inputs and outputs and corresponding conversion factors. Results reveal that the total input energy used in greenhouse...
An approach for minimisation of the capital costs and energy consumption in a district heating network is presented using a case study based on a district heating network in South Wales, UK. A number of different design cases were simulated using the PSS SINCAL, taking into account different supply and return temperatures and target pressure losses. The operation of the district heating network was...
We used energy and exergy analysis to evaluate two industrial and one ideal (theoretical) production process for silicon. The industrial processes were considered in the absence and presence of power production from waste heat in the off-gas. The theoretical process, with pure reactants and no side-reactions, was used to provide a more realistic upper limit of performance for the others. The energy...
In recent years, besides the energy issues, the GHG (greenhouse gas) emission, which is the most important cause of global warming, has received high attention. In order to have sustainable development, it is necessary to manage energy usage and GHG emissions in all production processes. This study aimed to evaluate the energy consumption and GHG emissions of cucumber production in selected greenhouses...
An advanced exergy analysis is reported for a recently developed configuration of an externally-fired combined-cycle power plant integrated with biomass gasification. The results identify the potential for improvement of the overall system considering interactions among the components. It is found that interactions between the components are not very strong, i.e. the endogenous exergy destruction...
This paper describes the thermodynamic analyses of a DAR (diffusion absorption refrigeration) cycle. The experimental apparatus is set up to an ammonia–water DAR cycle with helium as the auxiliary inert gas. A thermodynamic model including mass, energy and exergy balance equations are presented for each component of the DAR cycle and this model is then validated by comparison with experimental data...
The aim of this research was to compare the production systems of flat and sloping olive orchards and analyze the effect of land situation (flat and sloping) on use of energy input resources. The study conducted on olive orchards of Rudbar region, the origin of olive plant in Iran. The results showed that total energy input was 15.9 GJ ha −1 for flat orchards and 23.3 GJ ha −1 for...
Exergy analysis of any thermodynamic system can take care of the limitations of energy analysis such as irreversible losses, their magnitude and the source of thermodynamic inefficiencies apart from energy losses. In the present study, both the analyses along with heat release analysis are conducted on a natural aspirated diesel engine fuelled separately with palm biodiesel (PB), karanja biodiesel...
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