this paper discusses the performance evaluation and availability analysis of ammonia synthesis unit of a fertilizer plant. the fertilizer plant is a complex and repairable engineering system comprises of various units viz. shell gasification and carbon recovery, desulphurization, co-shift conversion, decarbonation, nitrogen wash and ammonia synthesis etc. one of the most important functionaries...

Pseudo–transient continuation methods are quite popular for the numerical solution of steady state problems, typically in PDEs. They are based on an embedding into a time dependent initial value problem. In the presence of dynamical invariants the Jacobian matrix of the nonlinear equation system is bound to be singular. The paper presents a convergence analysis which takes this property into ac...

A reactive distillation plant is one of the most important and “delicate” functional components of a complex chemical plant. While its steady state modeling and simulation tend to become a standard today by using some well known dedicated software tools, only little is known about the dynamic simulation in the open literature. This paper presents the principles for a modern modeling approach wi...

The observation of duality by Mukherji and Mishra in one dimensional transport problems has been used to develop a general approach to classify and characterize the steady state phase diagrams. The phase diagrams are determined by the zeros of a set of coarse-grained functions without the need of detailed knowledge of microscopic dynamics. In the process, a new class of nonequilibrium multicrit...

Abstract: This paper examines the steady state behavior of an M/G/1 queue with repeated attempts in which the server may provide an additional second phase of service. This model generalizes both the classical M/G/1 retrial queue and the M/G/1 queue with classical waiting line and second optional service. We carry out an extensive stationary analysis of the system, including existence of statio...

This paper presents a consistent LBM formulation for the simulation of a two-phase water–steam system. Results of initial model validation in a range of thermodynamic conditions typical for BoilingWater Reactors (BWRs) are also shown. The interface between the two coexisting phases is captured from the dynamics of the model itself, i.e., no interface tracking is needed. The model is based on th...

This paper is aimed to determine a general model for simulating the single and two-phase induction machines operation. The objective of this model is to predict motor performance parameters such as torque, and motor speed. The model includes representation of both main and auxiliary winding in stationary reference frame and also the effect of core losses and the saturation of the main flux path...

This paper describes a Matlab program designed to compute the switching over voltages which appear when no-load high voltage lines are energized. The mathematical models of the high voltage distribution lines are presented also. The Matlab program is applied for the case of the high voltage distribution lines from the 220kV network of the ST Craiova, for which the characteristic parameters are ...

This paper focuses on the computer cooling capacity using the thermosyphon loop with minichannels and minipump. The one-dimensional separate model of two-phase flow and heat transfer in a closed thermosyphon loop with minichannels and minipump has been used in calculations. The latest correlations for minichannels available in literature have been applied. This model is based on mass, momentum,...

This paper analyzes natural circulation flow in solid breeder blanket designs with poloidal coolant channels under a LOFA condition. Analyses couple the flow transient behaviors with transient heat transport models. While two-phase natural circulation exists in the system, a homogenous mixture model is used. The results of example calculations performed for an ITER solid breeder design concept ...