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Low-grade waste heat source accounts for a large part of the total industrial waste heat, which cannot be efficiently recovered. The ORC (Organic Rankine Cycle) system has been proved to be a promising solution for the utilization of low-grade heat sources. It is evident that there might be several waste heat sources distributing in different temperature levels in one industry unit, and the entire...
This paper investigates a thermal system that absorbs waste heat from an internal combustion (IC) engine in order to raise the temperature of a working fluid to a saturated state using thermosyphonic flow, non-intrusive of the engine operations. The absorbed heat is rejected to an enclosed space, suitable for in-transit drying. The thermal system comprises a cross-flow heat exchanger connected to...
More than two-thirds of the world's population is relying on biomass fuel to meet their cooking and heating energy-requirements. Traditional biomass stoves operate at low efficiency and cause severe health problems and pollute the environment. Due to higher quantity of fuel use, these cookstoves increase the burden on fuel management. Several test protocols are being used across the world for evaluating...
The Kalina split-cycle is a thermodynamic process for converting thermal energy into electrical power. It uses an ammonia–water mixture as a working fluid (like a conventional Kalina cycle) and has a varying ammonia concentration during the pre-heating and evaporation steps. This second feature results in an improved match between the heat source and working fluid temperature profiles, decreasing...
Electricity consumption in educational facilities has increased by an annual average of 9.84% since 2006. However, it is not considered as a factor in determining the AECB (annual energy cost budget) in South Korea. Therefore, this study aims to develop an estimation model for determining the AECB in educational facilities using the SARIMA (seasonal autoregressive integrated moving average) model...
A split concept for boilers and heat recovery steam generators (HRSG), where flue gas recycling is required for controlling the maximal temperature, is proposed for reducing the heat exchange area and/or the recycling power requirements. The concept is demonstrated in the context of an HRSG of a pressurized oxy-coal combustion process, where the hot flue gas entering the HRSG is diluted by recycled...
In this study, two fuels called as FOME (Fish Oil Methyl Ester) and COME (Cooking Oil Methyl Ester) were produced from waste fish and cooking oils using the transesterification method. Commercial D2 (Diesel fuel) and two fuel samples obtained by blending the FOME and COME with the D2 with a ratio of 25% on volume basis were used as fuels in a Diesel test engine. An experimental study was performed...
In this paper, we formulate a RLOPF (risk-limiting optimal power flow) problem for systems with high penetration of wind power to address the issue of possibly violating the security constraints in power systems due to the volatility of wind power generations. To cope with the computational complexity of the proposed RLOPF problem, we propose a computationally efficient RLOPF algorithm assisted by...
Reducing fuel consumption is a prime objective in order to meet regulatory and customer demands. Given this context, an original port fuel injected engine featuring variable valve actuation was initially investigated when operating at idle with low intake valve lift. An improvement of both fuel economy and engine cycle-to-cycle variability was recorded at idle operation, which is a prominent feature...
The melting thermal performances of MEPCM (microencapsulated phase-change material) composite plates were investigated experimentally. The effects of MEPCM particle fraction in the plate, PCM core fraction in a single MEPCM particle, volume fraction of high thermal conductivity additives on the temperature of heated and back surfaces, the temperature difference between both surfaces, and the melting...
Power systems are in the midst of radical changes as a result of steadily rising demand, advanced technology integration and increasing penetration levels of renewable energy sources. Such developments have brought about increasing recognition of consumer behavior and the provision of DR (demand response). The aggregation of small loads as a DR flexibility resource allows end-users to participate...
This paper reviews a published multi-criteria assessment of power systems and proposes new methods for normalization and ranking of criteria indicators. In previous work, the power systems are evaluated and ranked relative to the other systems considered in the assessment. This relative ranking system negatively affects the results in two ways. First, relative ranking tends to skew the results of...
The present study investigates the extraction of lignin from rice straw by bi-directional delignification methodology through minimal energy input towards feedstock preparation for bio-fuel production. In the first stage, the rice straw was treated with sodium chlorite of pH 5.5 followed by sodium hydroxide while in the second stage with sodium hydroxide alone under controlled parameters like, concentration,...
Air pollution and climate change increased the importance of renewable energy resources like solar energy in the last decades. Rack-mounted PhotoVoltaics (PV) and Building Integrated PhotoVoltaics (BIPV) are the most common photovoltaic systems which convert incident solar radiation on façade or surrounding area to electricity. In this paper the performance of different solar cell types is evaluated...
In this study, the effect of CR (compression ratio) on a SI (spark ignition) engine's characteristics of performance, combustion and emissions by using pure ethanol, methanol and unleaded gasoline were investigated experimentally. In the experiments, an SI engine having a CR of 8.5:1, having a single cylinder and air-cooled was used. These tests were conducted on four different CRs of 8.0:1, 8.5:1,...
Nowadays the control of greenhouse gas is probably the most challenging environmental policy issue. Since CO 2 is considered the major greenhouse gas (GHG) that contributes to the global warming, enforcing technological strategies aiming to avoid or reuse CO 2 emissions becomes crucial, in order to mitigate GHG environmental impact. Currently, solutions conventionally adopted to this...
In the present paper, the nominal design data and the experimental data of eleven industrial cogeneration power plants, based on different prime mover technologies and actually in operation in Italy, have been compared. The aim of the study is to compare the expected energetic and economic results with the real performance and economic profitability of the plants in operation: the analyses have highlighted...
The behavior of small turbochargers is deeply affected by heat transfer phenomena. The external heat losses of these machines are studied and a simplified model that takes into account both radiation and convective mechanisms has been proposed. The model has been adjusted in a turbocharger test bench for two different turbochargers, later on it has been validated against experimental measurements...
The present study assesses the performance of nine empirical models: the models of Bristow & Campbell and Hargreaves & Samani (together with their modified versions) in estimating the daily and monthly solar irradiation using just extraterrestrial solar irradiation and air temperature extremes (maximum and minimum) as input data. Two schemes to calculate the air temperature amplitudes (ΔT...
The objective of this work is to develop a non-stoichiometric equilibrium model to study parameter effects in the gasification process of a feedstock in downdraft gasifiers. The non-stoichiometric equilibrium model is also known as the Gibbs free energy minimization method. Four models were developed and tested. First a pure non-stoichiometric equilibrium model called M1 was developed; then the methane...
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