ENERGY EFFICIENCY BASED OPERATION OF COMPRESSED AIR SYSTEM ON SHIPS TO REDUCE FUEL CONSUMPTION AND CO2 EMISSION

Energy efficiency subject has been gaining importance in maritime sector. The compressed air is a valuable energy source in operational manner, by the reason of intrinsic lack of efficiency in pressurization process. Operational pressure and leakage rate are the major variables which affect operational efficiency of the system. This study aims to reveal potential energy saving for the compressed air system. To this end, several pressure ranges, 29-30 bars to 14-18 bars, and different leakage rates 2.4% to 45% are evaluated. After the data was obtained from ships, thermodynamic calculations had been carried out. Optimization of pressure saves 47.3% in daily power requirement, 58,2% in compressed air unit cost, 18.4 and 57.4 tons of reduction in fuel consumption and CO2 emissions in a year respectively. High leakage rates can cause 2.7 times more power and fuel consumption. Finally, operating load, as an important indicator of compressor, makes imperfections identifiable.

Fabrication and Characterisation of Organic EL Devices in the Presence of Cyclodextrin as an Interlayer

This study examined glass-based organic electroluminescence in the presence of a cyclodextrin polymer as an interlayer. Glass-based organic electroluminescence was achieved by the deposition of five layers of N,N’-Bis(3-methylphenyl)N,N’-bis(phenyl)-benzidine, cyclodextrin polymer (CDP), tris-(8-hydroxyquinolinato) aluminium LiF and Al on an indium tin oxide-coated glass substrate. The glass-based OEL exhibited green emission owing to the fluorescence of tris-(8-hydroxyquinolinato) aluminium. The highest luminance was 19,620 cd m−2. Moreover, the glass-based organic electroluminescence device showed green emission at 6 V in the curved state because of the inhibited aggregation of the cyclodextrin polymer. All organic molecules are insulating, but except CDP, they are standard molecules in conventional organic electroluminescence devices. In this device, the CDP layer contained pores that could allow conventional organic molecules to enter the pores and affect the organic electroluminescence interface. In particular, self-association was suppressed, efficiency was improved, and light emission was observed without the need for a high voltage. Overall, the glass-based organic electroluminescence device using CDP is an environmentally friendly device with a range of potential energy saving applications.

Evaluation methods of the daylight performance and potential energy saving of tubular daylight guide systems: A review

In the past 30 years, tubular daylight guide systems (TDGSs) have become one of the most popular ways to transport outdoor natural light into the inner space in building design. However, tubular daylight guide systems are not widely used because of the lack of methods to evaluate methods on the suitability of the TDGSs. This study therefore summarizes the daylight performance metrics of TDGSs and presents the estimation methods in terms of field measurements, simulation and empirical formulae. This study focuses on the daylight performance and potential energy savings of TDGSs. Moreover, this study will be helpful for building designers to build healthy, comfortable and energy-saving indoor environment.

An Investigation of Aerodynamic Effects of Body Morphing for Passenger Cars in Close-Proximity

The potential energy-saving benefit for vehicles when travelling in a ‘platoon’ formation results from the reduction in total aerodynamic drag which may result from the interaction of bluff bodies in close-proximity. Early investigations of platooning, prompted by problems of congestion, had shown the potential for drag reduction but was not pursued. More recently, technologies developed for connected-autonomous vehicle control have provided a renewed interest in platooning particularly within the commercial vehicle industry. To date, most aerodynamics-based considerations of platooning have been conducted to assess the sensitivity of drag-saving to vehicle spacing and were based on formations of identically shaped constituents. In this study, the interest was the sensitivity of drag-saving to the shape of the individual platoon constituents. A new reference car, the Resnick model, was specially designed to include front and rear-end add-on sections to make distinct changes in profile form and simulate large-scale body morphing. The results of wind tunnel tests on small-scale models suggested that current trends in low-drag styling may not provide the ideal shape for platoon constituent members and that optimised forms are likely to be dependent upon position in the platoon.

Closed Refrigerated Display Cabinets

The use of closed refrigerated display cabinets in supermarkets is in progression because of the potential energy saving compared to the open ones with an air infiltration at the front. However, the influence of the presence of doors on product temperatures (determining factor of product quality) is much less studied. For better understanding the interest of the use of closed display cabinets, this chapter presents the state of the art of field studies, the airflow and temperature profile in the closed display cabinet, the influence of the presence of doors/the frequency of door openings and the room temperature. Finally, a literature review of studies on food quality in the closed display cabinet is presented.

The adoption of energy efficiency and a policy framework for Zimbabwe

Recent policy discussions on energy use in Zimbabwe sparked interest in the economic case for energy efficiency, suggesting the need to investigate the relevant costs and benefits. This paper investigated the potential of energy efficiency in manufacturing industries in Zimbabwe. Data collection was done using questionnaires, walk-through audits and semi-structured interviews. The data set was then analysed using regression analysis. The results show that there would be significant potential energy saving in Zimbabwe through adopting various energy efficiency programmes. The main energy efficiency barriers identified were: poorly structured electricity tariffs; risk of production disruption; resistance of operational staff to a changed working style; lack of coordination between company divisions; lack of information on energy efficiency programmes; and lack of support from senior management on issues that relate to energy efficiency. A straightforward energy efficiency policy framework is proposed, and three main players identified, namely government, energy regulator, and research institutions.

Addressing Energy Efficiency by Periodical Energy Audits

The publication focuses on assessing the energy efficiency in residential and to some extent commercial applications. An energy audit is always the first step in addressing energy efficiency. The purpose of the publication is to present the benefits of using an energy audit. It explains a “do-it-yourself” procedure for an energy audit. The publication also focuses on calculating the potential energy saving by updating low-efficiency electric appliances with high-efficient alternatives. The environmental benefits of addressing the energy efficiency of households is also being discussed. An energy audit using a “do-it-yourself” procedure focuses on the economic, ecological and social impact to environment. The energy audit contributes to the implementation of the concept of sustainable development in our day by day life.

Impact of reflective roofs on the overall energy savings of whole buildings

Many previous studies by the authors of this paper and others have shown that installing white/reflective/cool roofing systems resulted in energy savings. The amount of energy savings depended on the longwave thermal emissivity and the short-wave solar reflectivity of the rooftop surfaces. The question is “what is the percentage energy savings for the whole building as a result of using cool roofing systems instead of conventional/black roofing systems? To answer this question, three-dimensional energy simulations are conducted for typical Saudi buildings when they are subjected to the natural weathering conditions of the Eastern Province of Saudi Arabia. Several Window-to-Wall Ratios (WWRs) having different thermal resistances (R-values) and Solar Heat Gain Coefficients (SHGCs) are considered in the study. The windows are located in the different main solar orientations. To investigate the effect of the area ratio of the roof to the walls on the potential energy saving due to using cool roofs, one storey and two-storey are considered in this study. Results showed that using reflective materials with lower short-wave solar absorption coefficients in the roofing systems have resulted in a decrease in the yearly total energy loads of one-storey building and two-storey building.