Paper 8: Maintenance Planning Applied to Plant Auxiliaries in the Central Electricity Generating Board

1966 ◽  
Vol 181 (14) ◽  
pp. 87-118
Author(s):  
V. J. Wright ◽  
R. E. Seymour ◽  
N. D. Norris
Keyword(s):  
Capital Investment ◽  
Critical Path ◽  
Effective Control ◽  
Service Experience ◽  
Technical Data ◽  
Design Engineers ◽  
Power Stations ◽  
Economic Methods ◽  
Minimum Requirements ◽  
The Cost

The C.E.G.B. operates 230 power stations of various ages and output capacities representing a total capital investment of some £2400 million. The steam conditions, sizes of generating units, and complexity of the installed plant reflect the stage of technical development at the time of their construction. These factors influence the cost of production at individual stations as also do the nature and cost of fuel. The economic level of maintenance at each station is thus dependent upon a number of factors and must generally be established locally. This places an obligation on the maintenance engineer to collect and consider economic, in addition to technical, data. Also, service experience must be fed back to the design engineer so that future plant designs may be improved. Unless a simple and effective control system is employed paper work can become an intolerable burden. Power station maintenance can be broadly divided between: (1) work which can only be carried out while a generating unit is shut down; (2) work which can be carried out with the main plant on load. The first category has received the greatest attention, since the cost of keeping a modern generator out of service can be substantial. Planning of this work is based on Critical Path Analysis techniques which are now well known and widely practised. However, the day-to-day maintenance of a large variety of auxiliary plant also presents a heavy planning burden upon the maintenance department. The basic minimum requirements for the effective local control of this work have been examined, while the most economic methods of: (a) co-ordinating maintenance in a number of stations in the best national interest, and (b) ensuring that service experience is fed back to design engineers are also receiving attention.

Exergoeconomic analysis of renewable multi-generation system

2020 ◽  
pp. 99-111
Author(s):  
Vontas Alfenny Nahan ◽  
Audrius Bagdanavicius ◽  
Andrew McMullan
Keyword(s):  
Capital Investment ◽  
Combined Cycle ◽  
Asian Countries ◽  
Generation System ◽  
Integrated Gasification Combined Cycle ◽  
Heating And Cooling ◽  
Integrated Gasification ◽  
Exergoeconomic Analysis ◽  
Main Components ◽  
The Cost

In this study a new multi-generation system which generates power (electricity), thermal energy (heating and cooling) and ash for agricultural needs has been developed and analysed. The system consists of a Biomass Integrated Gasification Combined Cycle (BIGCC) and an absorption chiller system. The system generates about 3.4 MW electricity, 4.9 MW of heat, 88 kW of cooling and 90 kg/h of ash. The multi-generation system has been modelled using Cycle Tempo and EES. Energy, exergy and exergoeconomic analysis of this system had been conducted and exergy costs have been calculated. The exergoeconomic study shows that gasifier, combustor, and Heat Recovery Steam Generator are the main components where the total cost rates are the highest. Exergoeconomic variables such as relative cost difference (r) and exergoeconomic factor (f) have also been calculated. Exergoeconomic factor of evaporator, combustor and condenser are 1.3%, 0.7% and 0.9%, respectively, which is considered very low, indicates that the capital cost rates are much lower than the exergy destruction cost rates. It implies that the improvement of these components could be achieved by increasing the capital investment. The exergy cost of electricity produced in the gas turbine and steam turbine is 0.1050 £/kWh and 0.1627 £/kWh, respectively. The cost of ash is 0.0031 £/kg. In some Asian countries, such as Indonesia, ash could be used as fertilizer for agriculture. Heat exergy cost is 0.0619 £/kWh for gasifier and 0.3972 £/kWh for condenser in the BIGCC system. In the AC system, the exergy cost of the heat in the condenser and absorber is about 0.2956 £/kWh and 0.5636 £/kWh, respectively. The exergy cost of cooling in the AC system is 0.4706 £/kWh. This study shows that exergoeconomic analysis is powerful tool for assessing the costs of products.

scholarly journals AN EXACT SOLUTION FOR THE RESOURCE-CONSTRAINED CONSTRUCTION SCHEDULING PROBLEM

2016 ◽  
Vol 8 (2) ◽  
pp. 71-78
Author(s):  
Bartłomiej Sroka ◽  
Elżbieta Radziszewska-Zielina
Keyword(s):  
Execution Time ◽  
Critical Path ◽  
Scheduling Problem ◽  
Resource Constrained ◽  
Building Projects ◽  
Construction Scheduling ◽  
Program Sample ◽  
Resource Constrained Scheduling Problem ◽  
The Cost ◽  
Exponential Complexity

Reduced time and, by the same token, the cost of the project is a crucial factor in contemporary construction. This article presents a method for the exact optimisation of a resource-constrained scheduling problem. Based on the Critical Path Method, graph theory and linear programming, an algorithm was developed and the FROPT program was written in Matlab to minimise the execution time of the task. By using the newly-created program, sample networks were calculated and the results were compared with results obtained by using the MS Project scheduling program (using approximation algorithm). The execution time obtained by using FROPT were on average 10% shorter than those obtained using MS Project. In selected cases the improvement in execution time reached 25%. A deterministic approach to the problem may shorten planned project times and bring financial benefits. Due to the exponential complexity of the algorithm, it is most useful in solving small or highly coherent networks. The algorithm and program may result in benefits not offered by commercial software for planners of building projects.

Preliminary Estimates of Costs of Foodborne Disease in the United States

1989 ◽  
Vol 52 (8) ◽  
pp. 595-601 ◽  
Author(s):  
EWEN C. D. TODD
Keyword(s):  
United States ◽  
Food Industry ◽  
The United States ◽  
Control Measures ◽  
Effective Control ◽  
Foodborne Diseases ◽  
Hemorrhagic Colitis ◽  
E Coli ◽  
The Cost ◽  
Total Impact

Although the full economic impact of foodborne diseases has yet to be measured, preliminary studies show that the cost of illness, death, and business lost is high indeed. This impact is probably greatest in developing countries, but few facts are known. For the United States, preliminary estimates are 12.6 million cases costing $8.4 billion. These may seem excessive but other authors have postulated even higher case and dollar figures. Microbiological diseases (bacterial and viral) represent 84% of the United States' costs, with salmonellosis and staphylococcal intoxication being the most economically important diseases (annually $4.0 billion and $1.5 billion, respectively). Other costly types of illnesses are toxoplasmosis ($445 million), listeriosis ($313 million), campylobacteriosis ($156 million), trichinosis ($144 million), Clostridium perfringens enteritis ($123 million), and E. coli infections including hemorrhagic colitis ($223 million). Botulism has a high cost per case ($322,200), but its total impact is only $87 million because relatively few cases occur (270). This is because the food industry has been able to introduce effective control measures. Salmonellosis, however, is much more widespread (2.9 million cases) and affects all sectors of the food industry.

What Drives a Successful Technology Implementation?

2013 ◽  
pp. 340-357
Author(s):  
Kawal Kapoor ◽  
Yogesh K. Dwivedi ◽  
Michael D. Williams ◽  
Mohini Singh ◽  
Mark J. Hughes
Keyword(s):  
Public Sector ◽  
Radio Frequency Identification ◽  
Technology Implementation ◽  
Capital Investment ◽  
Stock Management ◽  
Implementation Team ◽  
Public Sector Organizations ◽  
Self Service ◽  
The Individual ◽  
The Cost

Radio Frequency Identification (RFID) is revolutionizing item identification and tracking. The technology demonstrates complexities in terms of (a) huge initial capital investment, (b) validating the need for RFID followed by its implementation decisions, (c) risks associated with consumer acceptance and consequences of incorrect implementation, and (d) capability to support enhancements and upgrades in cordial agreement with the individual implementer organizations. This paper explores the extent of RFID implementation at the Swansea University Library, examining the Social, Technological, Economic, and Managerial (STEM) aspects directly associated with implementation. A focused interview approach was resorted to, for data collection purposes. The core implementation team for RFID at Swansea University was interviewed to gain insights into the study’s areas of interest. It was found that self service is the most sought after benefit. It simplifies stock management and enhances security at the libraries. Although the cost of the system remains a concern, varying on the basis of the scale of implementation, vandalism also continues to exist but to a reduced degree. University libraries are public sector organizations, consequently leading these findings to have an insinuation for RFID implementations in other public sector organizations as well.

Distillation-based Separation Systems Synthesis

1995 ◽  
Author(s):  
Christodoulos A. Floudas
Keyword(s):  
Capital Investment ◽  
Optimal Configuration ◽  
Synthesis Problem ◽  
Total Annual Cost ◽  
Separation Processes ◽  
Distillation Columns ◽  
Separation Systems ◽  
Total Capital ◽  
Separation Sequence ◽  
The Cost

This chapter presents two applications of MINLP methods in the area of separations. Section 9.1 provides an overall introduction to the synthesis of separation systems. Section 9.2 focuses on sharp heat-integrated distillation sequencing. Section 9.3 presents an application of nonsharp separation synthesis. The synthesis of distillation-based separation sequences has been one of the most important subjects of investigation in the area of process synthesis. This is attributed to the significant contribution of separation processes to the total capital investment and operating expenses of a chemical plant. As a result, a lot of interest has been generated in the development of systematic approaches that select optimal sequences of distillation columns. Westerberg (1985) provided a comprehensive review of the distillation-based separation synthesis approaches, as well as presented a classification of different types of separation problems along with their associated challenges. Nishida et al. (1981) and Smith and Linnhoff (1988) reviewed the general separation synthesis problem (i.e., not only distillation-based) and presented the progress made. To illustrate the nature of the distillation-based separation system synthesis problem, let us consider its generic definition shown in Figure 9.1, which is as follows: . . . Given a number of input multicomponent streams which have specified amounts for each component, create a cost-optimal configuration of distillation columns, mixers, and splitters that produces a number of multicomponent products with specified composition of their components. . . The products feature components that exist in the input streams and can be obtained by redistributing the components existing in the input streams, while the cost-optimal configuration corresponds to the least total annual cost one. Most of distillation columns or sequences can be classified as (i) Sharp, (ii) Nonsharp, (iii) Simple, (iv) Complex, (v) Heat-integrated, and (vi) Thermally coupled. In (i), a column separates its feed into products without overlap in the components. An example is the separation of a stream consisting of four components A, B, (C, and D via a distillation column, into one product consisting of only A and another product featuring B, C, and D. If all columns are sharp, then the separation sequence is termed as sharp sequence.

scholarly journals Backward Bifurcation and Optimal Control Analysis of a Trypanosoma brucei rhodesiense Model

Mathematics ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 971
Author(s):  
Mlyashimbi Helikumi ◽  
Moatlhodi Kgosimore ◽  
Dmitry Kuznetsov ◽  
Steady Mushayabasa
Keyword(s):  
Optimal Control ◽  
Trypanosoma Brucei ◽  
Backward Bifurcation ◽  
Effective Control ◽  
Control Analysis ◽  
Trypanosoma Brucei Rhodesiense ◽  
Awareness Campaigns ◽  
Human Animal ◽  
The Cost ◽  
Insecticide Control

In this paper, a mathematical model for the transmission dynamics of Trypanosoma brucei rhodesiense that incorporates three species—namely, human, animal and vector—is formulated and analyzed. Two controls representing awareness campaigns and insecticide use are investigated in order to minimize the number of infected hosts in the population and the cost of implementation. Qualitative analysis of the model showed that it exhibited backward bifurcation generated by awareness campaigns. From the optimal control analysis we observed that optimal awareness and insecticide use could lead to effective control of the disease even when they were implemented at low intensities. In addition, it was noted that insecticide control had a greater impact on minimizing the spread of the disease compared to awareness campaigns.

Pipework Purging by Water Flushing

1973 ◽  
Vol 187 (1) ◽  
pp. 801-808
Author(s):  
R. R. Cranfield ◽  
J. Lawrence
Keyword(s):  
Calculated Data ◽  
Water Velocity ◽  
Normal Operation ◽  
Power Stations ◽  
The Cost

In power stations it has been the practice to purge newly erected steam pipework of debris by blowing through steam at a higher rate than in normal operation. The cost of providing sufficient steam from temporary boilers can be high in some cases. This paper presents the results of a study of water flushing as a method of removing debris from pipework. The minimum necessary water velocity for varying pipe sizes can be calculated, data are given for purge time and pipework configurations are examined.

Techno-Economic Feasibility Analysis of Pumped Storage Hydroelectricity in Abandoned Underground Coal Mines

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Dacheng Shang ◽  
Peng Pei ◽  
Yujun Zuo
Keyword(s):  
Coal Seam ◽  
Capital Investment ◽  
Economic Feasibility ◽  
Abandoned Mines ◽  
Cost Of Energy ◽  
Calculation Results ◽  
Pumped Storage ◽  
Geological Constraints ◽  
The Cost ◽  
Cycle Efficiency

Abstract It is anticipated that utilizing the underground space in abandoned mines to build and operate pumped-storage hydroelectricity (PSH) plants can reduce capital investment and geological constraints. However, there are currently few detailed investigations into techno-economic feasibility except for conceptual studies. In this paper, an underground coal mine in Guizhou, China was used as a reference, and the PSH layout was designed; in addition, the head loss, plant efficiency, and major cost components were investigated. The calculation results show that the capital investment of mine-based PSH was 33–50% less than that of conventional PSH. Sensitivity analysis found a clear influence of coal seam inclination on the performance of the mine-based PSH. Under the assumed conditions, the plant cycle efficiency increased from 62.7% to 71.5% when the coal seam dip varied from 5 deg to 25 deg. Depending on different price scenarios, when the coal seam inclination was steep enough, the cost of energy storage of a mine-based PSH plant was competitive compared with conventional PSH, and the plant could even become profitable. The influence of the dip of coal seam was more pronounced when in the lower range (5–15 deg) than the higher range (15–25 deg).

scholarly journals COMPARAÇÃO ENTRE OS TRATAMENTOS COM TANASE E COM GELATINA PARA CLARIFICAÇÃO DO SUCO DE CAJU ( Anacardium occidentale L.)

2002 ◽  
Vol 20 (1) ◽  
Author(s):  
SONIA COURI ◽  
LUCIANE FERREIRA DE MENEZES ◽  
GUSTAVO ADOLFO SAAVEDRA PINTO ◽  
MARIA DE LOURDES M. SOUZA ◽  
SUELY PEREIRA FREITAS
Keyword(s):  
Economic Analysis ◽  
Capital Investment ◽  
Apple Juice ◽  
Anacardium Occidentale ◽  
Tannin Content ◽  
Cashew Apple Juice ◽  
Hydrolysable Tannin ◽  
Juice Clarification ◽  
Cashew Apple ◽  
The Cost

Comparou-se o tratamento da polpa do caju com tanase e com gelatina, visando à redução da turbidez e do teor de taninos. Os resultados indicaram que a redução das concentrações de taninos totais, hidrolisáveis, proantocianidinas e turbidez ficaram em 39%, 50%, 32% e 94% para sucos tratados com gelatina e 46%, 88%, 2% e 88% para a polpa tratada com tanase, respectivamente. Deste modo, o tratamento com gelatina foi eficiente para remoção de proantocianidinas, enquanto que o tratamento enzimático foi mais eficiente na redução de taninos hidrolisáveis. Os produtos obtidos não apresentaram diferenças visuais. Estudo comparativo de pré-viabilidade econômica mostrou que o investimento de capital para obtenção do suco de caju clarificado com enzima é menor que para o suco clarificado com gelatina. Entretanto, o custo de produção do suco de caju clarificado com gelatina é menor devido ao preço elevado da enzima tanase. COMPARISION OF THE CASHEW APPLE (Anacardium occidentale L.) JUICE CLARIFICATION WITH TANNASE AND GELATIN Abstract Tannase and gelatin were compared for treatment of cashew apple pulp aiming to reduce turbidity and tannin content. The results indicated that the decrease in concentrations of total tannin, hydrolysable tannin, proanthocyanidin, and turbidity was 39%, 50%, 32% and 94% for juices treated with gelatin and 46%, 88%, 2% and 88% for pulp treated with tannase, respectively. In this way the treatment with gelatin was more efficient to remove proanthocyanidin, whereas enzymatic ones was better for hydrolysable tannin decrease. The obtained products didn’t present visual differences. The comparative economic analysis for the cashew-apple juice production showed that the capital investment for the enzymatic clarification is lower than for the conventional clarification process, using gelatin. Although, the cost of clarified cashew apple juice using gelatin is lower due to the high cost of the enzyme tannase.

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