Exergy Analysis and Efficiency Improvement of a Coal Fired Thermal Power Plant in Queensland

Energy analysis is an important tool to improve energy efficiency of a thermodynamic system. The conventional method of energy analysis is based on the first law of thermodynamics, which focuses on conservation of energy. The limitation of this analysis is that it does not take into account properties of the system environment, or degradation of the energy quality through dissipative processes. Exergy analysis is very effective in this regard, as it deals with the usable energy with reference to environment. It is based on the second law of thermodynamics. The main purpose of exergy analysis is to identify where and how much exergy is destroyed. This destruction of exergy in a process is proportional to the entropy generation in it, which accounts for the inefficiencies due to irreversibility. This research conducts exergy analysis in one unit of a coal-fired power plant in Central Queensland, Australia. The exergy analysis identifies where and how much exergy is destroyed in the system and its components. Based on the analysis, it assesses different options to improve the efficiency of the system. It shows that only a small amount of useful energy can be recovered through a heat recovery system. Substantial improvement to the thermodynamic cycle is possible, but it requires considerable alteration of the power generation system

Prevalence of ectoparasites in farmed Pangasius hypothalamus

Of the total 240 Pangasius hypothalamus (5 - 8.7cm) fry examined during September' O1 to February'02, 80 (33.33%) were found to be infested with one or more ecroparasites irrespective of genera or groups. Seven parasitic groups were identified with the highest average prevalence of Trichodinids (55%) followed by Dacrylogyrus spp. ( 42%), Episrylis spp. (8%), Apiosoma spp. (7%) Argulus spp. (5%), Gyrodacrylus spp. (4%) and Piscicola spp. (2%) the lowest prevalent group irrespective of months. Trichodinid and Dacrylogyms spp. were recorded to be the dominating parasitic groups among the seven both in terms of monthly prevalence and severity of infestation throughout the period of investigation. The highest prevalence (60%) of ectoparasite was recorded in December and the lowest (10%) in February irrespective of groups

Biofuel: An Australian Perspective in Abating the Fossil Fuel Vulnerability

AbstractThe fossil fuels are now considered as one of the most environmentally unsustainable energy resources though they are the major energy source for transport sectors and other industries. Increased demand of fuel consumption can lead to the threat of energy supply instability and the consequences of energy uses and emission on both environment and economy are significant concerns of most of the countries. This article reviews the vulnerability of Australian fuel supply chain and a brief description on how biofuels can turn into significant alternative resources of fossil fuel. It has been observed that the prospective applications of biofuel can assist in abating both the greenhouse gas (GHG) emissions and fossil fuel vulnerabilities. Currently, Australia imports about 37% of the total crude oil demand managing a diverse supply chain system. The local refining capacities are not utilized properly. No more technically advanced projects are under consideration to achieve self-sufficiency to make the best use of domestic crudes in order to reduce the fuel imports. Though Australia possesses abundant facility of producing inedible biofuel feedstocks, high costs for feedstock processing has caused shut down of 68% of the existing biofuel refineries. But, biofuels can reduce over 60% of the GHG emissions caused by the same amount of fossil fuels. Though the Government has granted an excise of flat tax on biofuels until 2021 to promote the commercial growth in this sector, the lack of infrastructure investment from the Government has been slowed the progress of this industry since its inception. Establishment of regional biofuels refineries can reduce both the distribution transport cost and import load of the fossil fuels. Being alternative resources, biofuel production can effectively make the best use of deserted or unused lands, creating employment opportunities and reducing both fossil fuel market instability and environment pollutions

A Study on Thermo-catalytic Degradation for Production of Clean Transport Fuel and Reducing Plastic Wastes

AbstractBoth the landfilling and incineration processes of plastic waste management system are identified as sources of pollutant gas emitters. Reprocessing is also uneconomical in comparison to the virgin plastic products in terms of commercial values due to polymeric contamination. This article studies the thermo-catalytic conversion processes waste plastics. The reaction conditions and the quantification of types of catalysts used for the conversion processes influenced the quality of the resultant hydrocarbons. Obtaining higher yield of conversion and transport grade fuel require more investigation to adapt this technical process as one of the effective alternative resources for fuel production. Thermo-catalytic process resolves the problem of halogen contents in the PVC type plastics by converting them into residues with the use of NaHCO3 and AgNO3 which capture chlorine type products from the gaseous hydrocarbons. Addition of catalysts in the convenient reactor reduces the requirement of higher temperature operations like thermal cracking processes and produces more liquefied products. It has been observed that, the aromatic plastic contents should be observed during the conversion process to obtain fuels based on allowable aromatic contents according to the fuel standards and emission regulations implemented in respective regions. The temperature of the process need to be controlled as per the boiling points of the mixture contents to avoid formation of vapor in the reactor which could causes sticky adherence to the reactor walls. A continuous liquid fractionating distillation process can reduce the formation of light gases in the yield. It was also found that the mixture of LDPE, HDPE, PP and PS yield 87.19% fuel with 20 wt% ZnO catalyst at 200 – 400°C in a steel reactor. These fuels can be used directly in the automotive engines or can be retreated in the refineries to divide into gasoline and diesel fuels as per carbon chains. Since the plastic feedstocks do not contain any sulfur components the produced fuel can be treated as clean enough. Thus the fuels produced from this process can be considered as one of the potential alternative resources of fuel production resulting into an effective reduction of plastic wastes in a country

A New Handover Management Model for Two-Tier 5G Mobile Networks

There has been an exponential rise in mobile data traffic in recent times due to the increasing popularity of portable devices like tablets, smartphones, and laptops. The rapid rise in the use of these portable devices has put extreme stress on the network service providers while forcing telecommunication engineers to look for innovative solutions to meet the increased demand. One solution to the problem is the emergence of fifth-generation (5G) wireless communication, which can address the challenges by offering very broad wireless area capacity and potential cut-power consumption. The application of small cells is the fundamental mechanism for the 5G technology. The use of small cells can enhance the facility for higher capacity and reuse. However, it must be noted that small cells deployment will lead to frequent handovers of mobile nodes. Considering the importance of small cells in 5G, this paper aims to examine a new resource management scheme that can work to minimize the rate of handovers for mobile phones through careful resources allocation in a two-tier network. Therefore, the resource management problem has been formulated as an optimization issue that we aim to overcome through an optimal solution. To find a solution to the existing problem of frequent handovers, a heuristic approach has been used. This solution is then evaluated and validated through simulation and testing, during which the performance was noted to improve by 12% in the context of handover costs. Therefore, this model has been observed to be more efficient as compared to the existing model

An Experimental Study of Bubble Rise Characteristics in non – Newtonian (Power-Law) Fluids

Air bubbles are used in chemical, biochemical, environmental, food process such as sugar industries for improving the heat and mass transfer. In particular, the bubble rise characteristics in massecuite - a fluid made from sugar crystals and sugar syrup have a great influence on vacuum pan operation which is an important process for the production of raw sugar in sugar industries. An experimental study of the bubble rise characteristics in xanthan gum solutions, a non-Newtonian (Power-Law) massecuite equivalent fluid are presented in this paper. The main characteristics, i.e. the bubble velocity, the bubble trajectory, and the drag relationship were investigated as a function of volume of air bubbles. The bubble rise velocity and trajectory were measured using a combination of non-intrusive (high speed photographic) method and digital image processing. The parameters that significantly affect the rise of air bubble are identified. The effect of different bubble volumes and liquid heights on the bubble rise velocity and bubble trajectory are analysed and discussed. A relationship between the Reynolds number and the drag coefficient is presented and discussed

Culture feasibility of african catfish (Clarias gariepinus Lin.) fry in glass tank and synthetic hapa system using supplemental diets

An experiment was carried out with 1 0 days old Clarias gariepinus fry over a period of 42 days to determine the effects of different feeds on growth and survival of African catfish fry in glass tanks. The experiment was designed into four treatments each having three replications. Thus treatment 1 (T1) was named as Tank Tubifex (TT) and treatment 2 (T2) as Tank Sabinco (TS), treatment 3 as Pond Tubifex (PT), and treatment 4 (T4) as Pond Sabinco (PS). Live Tubifex (protein levels 64.48%) was supplied to treatments 1 and 3 and rest of the treatments were supplied Sabinco starter-1 (protein levels 40.13%). The highest and the lowest growth in total length and weight were 12.90cm, 18.77g and 6.17cm, 4.04g recorded from the treatments 3 and 2, respectively. Growth of catfish fry under treatment 3 in terms of both length and weight were significantly higher (P<0.01) than those of the other treatments. However treatment 2 showed the significantly lowest (P<0.01) growth performance among the various treatments. The highest survival rate (92%) was also obtained with treatment 3. Tubifex proved to be the best larval feed in respect of growth and survival rate

Culture potentials of climbing perch, Anabas testudineus (Bloch) under different stocking densities at semi-intensive management

Anabas testudineus was cultured at different stocking density for the period of five months from May to September. Three stocking densities such as 50,000 (Treatment-1, T1), 56,250 (Treatment-2, T2) and 62,250/ha (Treatment-3, T3) were tested with three replications. After five months rearing, the mean weights of koi were 46.74±2.59, 40.44±2.98 and 37.27±3.01 in T-1, 2 and 3, respectively. The calculated production of native koi in T1 T2 and T3 were 1,916±314, 1,774.31 ±260 and 1,431 ±297 kg/ha, respectively which were significantly different (p<0.05) from each other

Biology of the penaeid shrimp populations exploited by Estuarine Set Bagnet

Results of analysis of part of the data collected during October, 1989 to December, 1990 are given on the biology and catch assessment studies on the Estuarine Set Bagnet (ESBN) from six sampling stations covering the entire coast line of Bangladesh. Length frequency analysis of seven most commonly occurring penaeid shrimp species have been done with complete ELEFAN software package. The result of exploitation patterns indicate that all penaeids except P. stylifera are being over exploited on their way back to the Sea from the nursery ground. This appeared to be the instances of serious growth over fishing. These species are exploited at a size much lower than the length at first maturity, which strongly suggests a complete withdrawal of the bagnet fishery from the coast of Bangladesh