摘要:

AbstractEconomic and technological evaluation of processes.The process engineer is finding it increasingly important to evaluate a given process from the economic and technological standpoint, when developing a process or realizing an investment project. In order to demonstrate the possibility of a structured and systematic mode of procedure, a brief account is given of the available tools. Profitability can be evaluated on the basis of the accounting rate of return (ROI), the internal rate of return (dcf yield), and the ratio of equity, all measures that can be derived from an assessment of costs and economics. To take into account the uncertainty of the boundary conditions assumed, such as raw materials costs, selling prices, and plant utilization, it is advisable to carry out a risk and sensitivity analysis. Examples are given that demonstrate the possibility of both calculating and reducing the economic and technological risks.

ISSN:0009-286X    

DOI:10.1002/cite.330620103

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330620102

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractFlowsheeting systems for process simulation.Simulation of process plants with flowsheeting systems has been state of the art in chemical plant design and in the chemical industry for many years. Modern computers now permit steady state simulation of complex chemical plants with sufficient accuracy. This paper outlines the different approaches to steady state process simulation, names the advantages and disadvantages, and gives an outlook on further developments. Process optimization, process integration, and process synthesis will be discussed. The integration of different programs, e.g. the connection between flowsheeting systems and computer‐aided design (CAD) will be described. An advance in user friendliness will be reached by latest developments in the field of personal computers and workstations and by database management system

ISSN:0009-286X    

DOI:10.1002/cite.330620104

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractApplication of statistical testing to mixing.Assessment of the homogeneity of mixtures of solids and determination of the necessary mixing times are performed with the aid of statistical testing methods. The results from the basis for necessary decisions. Since reliable statements are fundamentally impossible in mathematical statistics, all such decisions are, with a certain probability, false, i.e. involve some risk. In studies of mixing, the first kind of error concerns the risk of rejecting a mixture although its homogeneity satisfies requirements, while the second kind of error concerns the risk of accepting a mixture although its homogeneity is insufficient. It is shown that barriers can be introduced for both kinds of error, and how to do this. Both the sample size and the limits of the acceptance range for the sample variance are thus laid down. If no decision is to be made concerning acceptance or rejection of a given mixture, but information is merely required about the mixing quality after a given time then this is accomplished by statement of confidence intervals.

ISSN:0009-286X    

DOI:10.1002/cite.330620105

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330620106

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractRadiation exchange calculations by the Monte Carlo method. Theory and applications to industrial combustion systems.The goal of this contribution is to indicate possible applications of the Monte Carlo method to calculation of radiation exchange process in combustion plant. A brief introduction to the method is accompanied by an account of modelling of radiation exchange and a description of the optical properties of the combustion chamber suspension. The Monte Carlo model used is presented and special formulations are given. The application of the method for the calculation of technical combustion systems is illustrated for two large‐scale combustion plant (coal‐ and lignite‐fired). Flow and thermal yield are estimated in order to reduce the computational effort and to achieve industrially relevant applicability. The simulated results show good agreement with available measurements. Coupling with complete flame and combustion chamber models in which turbulent binary flow and local heat liberation are calculated is feasible and is discussed in the final se

ISSN:0009-286X    

DOI:10.1002/cite.330620107

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330620108

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330620109

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330620110

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330620111

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY