Infrastructure Engineering - Research Publications
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ItemNo Preview AvailableThe proposed heating and cooling system in the CH2 building and its impact on occupant productivity(Australian Institute of Quantity Surveyors, 2005-12-31)Melbourne's climatic conditions demand that its buildings require both heating and cooling systems. In a multi-storey office building , however, cooling requirements will dominate. How the internal space is cooled and ventilation air is delivered will significantly impact on occupant comfort. This paper discusses the heating and cooling systems proposed for the CH2building. The paper critiques the proposed systems against previous experience, both internationally and in Australia. While the heating system employs proven technologies, less established techniques are proposed for the cooling system. Air movement in the shower towers, for example, is to be naturally induced and this has not always been successful elsewhere. Phase change material for storage of "coolth" does not appear to have been demonstrated previously in a commercial building, so the effectiveness of the proposed system is uncertain. A conventional absorption chiller backs up the untried elements of the cooling system, so that ultimately occupant comfort should not be compromised.
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ItemModeling Australian road transport emissions till 2025(The Institution of Engineers, Bangladesh, 2006)The contribution of the road transport sector to local air pollutants is significant in urban areas. Also, road transport has been a major source of greenhouse gases in OECD countries. In Australia, road transport was responsible for 12.9% of total national greenhouse gas emissions in 2000. This paper aims at determining the criteria air pollutants and greenhouse gas emissions from the road transport sector in Australia. Transport activities are projected from a bottom-up approach for a modeling period from 2000 to 2025. Instead of using standard drive cycle emission factors, attempts have been made to quantify real-world on-road emissions. Results have been compared with the findings from existing studies. It was found that the emission of local air pollutants would be decreasing because of the new vehicle emission standards to be adopted and by 2025. CO, HC, NOx and PM10 emissions would be significantly lower than the current level. Among the greenhouse gases, CH4 and N2O emissions are expected to decrease. The tailpipe CO2 emission would stabilize or increase at a very slow rate, because of the expected increase in fuel efficiency. The equivalent CO2 emission considering the global warming potential of CH4 and N2O is also predicted to stabilize.
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ItemAn evaluation of a proposed ventilation system for Melbourne's CH2 building(Australian Institute of Quantity Surveyors, 2005-12-31)The understanding of ventilation requirements in commercial buildings has been significantly revised in the last 10-15 years. A link between health, productivity and increased fresh air use has been established by some research and this understanding underpins the ventilation philosophy adopted for the CH2 building. The ventilation system design for CH2 that has been evaluated in this paper envisages a mechanically driven system during the day, using the displacement technique to distribute filtered air. All introduced air will be drawn from outside and no recycling of air will occur. Natural ventilation will be employed at night using the stack effect, enhanced by turbine ventilators. This paper critiques the proposed ventilation system in the light of international experience and the particular conditions of the building's location. The evidence suggests that natural ventilation sometimes may be inadequate to achieve the desired objectives. Minimization of indoor pollutants, adequate filtration and high levels of ventilation should, however, ensure satisfactory air quality during occupied hours.
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ItemAn ice thermal storage computer model(Elsevier, 2001-12-01)In hot humid countries such as Thailand, air conditioning plant is installed in most commercial and industrial buildings. A conventional air conditioning system, which is normally operated when cooling is required, is the most favored option. Ice thermal storage on a large scale, used to provide a cool reservoir for use in peak periods, is however an attractive financial option for large buildings to supply coolness. There are two means of operating ice thermal storage systems, namely full storage and partial storage. In this paper, a computer model has been developed in order to compare energy use in conventional air cooling systems and ice thermal storage systems. Under Thailand electricity tariff rates, the results from the simulations show that the full ice thermal storage can save up to 55% of the electricity cost required for cooling per month when compared with the conventional system. It is also found that using full storage option can reduce the total energy consumption by 5% for the selected building.
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ItemNo Preview AvailableThe potential of wood gasifiers for tea drying in Sri Lanka(RERIC, 2001-12-01)One of the reasons for the higher production cost of tea in Sri Lanka compared to other countries is the high specific energy consumption. In Sri Lanka, 38% more energy is used to produce one kilogram of tea compared to India, largely because of the use of inefficient wood-fired air heaters. Gasifiers have been proposed as an alternative method of providing the hot air used for drying. A locally built gasifier has been tested and found to have a conversation efficiency of 80%, which is comparable to that of an imported unit. The heat loss of local gasifier was found to be between 11.5-14% of the input energy. An analysis shows that the life cycle cost of energy produced by the gasifier is US$ 3.00 per GJ, which is 8% less than the cost of energy from a conventional wood heater. Wood consumption is also reduced by 12%. Some transfer of gasifier technology to the crematoria industry in Sri Lanka has already occurred and this enhances the prospect of the successful introduction of this technology to the tea industry.
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ItemBenefits of cool thermal storage in Thailand(RERIC, 2001-06-01)The use of thermal storage on a large to provide a cool reservoir for use in peak periods is an attractive financial option for large hotels, hospitals or office blocks. This enables the refrigeration plant to operate more effectively and to be completely or partially shut down during peak periods when the demand can be met in full or in part from the cool store. In this paper an overview is given of the power generation capacity and costing structure in Thailand and a typical load profile is presented to illustrate the advantages to be gained by shifting plant operation to off-peak periods. Specific load calculations have been utilized to demonstrate the cost savings possible by incorporation of such a cool thermal storage system into a traditional refrigeration and air conditioning plant for a major hotel complex.
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ItemComputer simulation of a downdraft wood gasifier for tea drying(Elsevier, 2003-10-01)A gasifier has been fabricated in Sri Lanka for the tea industry, but there is a lack of knowledge of the effect of certain key operating parameters and design features on its performance. Experimental testing of the design under various conditions has produced data that has then been used to calibrate a computer program, developed to investigate the impact of those parameters and features on conversion efficiency. The program consists of two sub-models of the pyrolysis and gasification zones, respectively. The pyrolysis sub-model has been used to determine the maximum temperature and the composition of the gas entering the gasification zone. The gasification zone sub-model has been calibrated using data gathered from the experiments. It was found that a wood chip size of 3–5 cm with a moisture content below 15% (d.b.) should be used in this gasifier. Feed material with a fixed carbon content of higher than 30% and heat losses of more than 15% should be avoided. For the above parameters, the gasification zone should be 33 cm long to achieve an acceptable conversion efficiency.
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ItemElectrical and engine driven heat pumps for effective utilisation of renew-able energy resources(PERGAMON-ELSEVIER SCIENCE LTD, 2003-07)