Reliability Software to Design New Generating Plants

2004 ◽  
Author(s):  
J. K. August ◽  
Krishna Vasudevan ◽  
W. H. Magninie
Keyword(s):  
Failure Modes ◽  
Operating Cost ◽  
Commercial Production ◽  
Equipment Failure ◽  
Plant Design ◽  
Economic Success ◽  
Maintenance Costs ◽  
Defining System ◽  
System Requirements ◽  
And Control

Engineers design plants with overall income and operating cost objectives in mind. Defining system requirements, component functions, and failure modes, they discern risks that drive design. Maintenance costs get considered as an afterthought. Misunderstanding significant equipment failure modes greatly changes profitability. Improving certainty of plant economic success requires reducing the risk of unknown failures. Unanticipated operating restrictions can hobble commercial production. Avoiding unanticipated problems sustains predictable costs and operations. Relational software can reduce economic operating risk during plant design to project and control operating risks and maintenance costs.

scholarly journals A SIMPLE FIVE-STEP METHODOLOGY TO DETERMINE CONTROLLABILITY OF HEAT EXCHANGER NETWORKS USING STEADY-STATE INFORMATION

2011 ◽  
Author(s):  
Rodolfo Tellez ◽  
William Y. Svrcek ◽  
Brent R. Young
Keyword(s):  
Steady State ◽  
Heat Exchanger ◽  
Process Integration ◽  
Plant Design ◽  
State Information ◽  
Step Procedure ◽  
Heat Exchanger Networks ◽  
Propose Control Strategy ◽  
Optimum Heat ◽  
And Control

Process integration design methodologies have been developed and introduced to synthesise an optimum heat exchanger network (HEN) arrangement. However, controllability issues are often overlooked during the early stages of a plant design. In this paper we present a five-step procedure that involves the use of multivariable disturbance and control analyses based solely on steady-state information and with the purpose to assess process design developments and to propose control strategy alternatives appropriate and suitable for a HEN.

scholarly journals Foaming of rhamnolipids fermentation: impact factors and fermentation strategies

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhijin Gong ◽  
Ge Yang ◽  
Chengchuan Che ◽  
Jinfeng Liu ◽  
Meiru Si ◽  
...  
Keyword(s):  
Production Process ◽  
Large Scale ◽  
Commercial Production ◽  
Impact Factors ◽  
Scale Production ◽  
Large Scale Production ◽  
Foaming Behavior ◽  
Production Strategies ◽  
Potential Applications ◽  
And Control

AbstractRhamnolipids have recently attracted considerable attentions because of their excellent biosurfactant performance and potential applications in agriculture, environment, biomedicine, etc., but severe foaming causes the high cost of production, restraining their commercial production and applications. To reduce or eliminate the foaming, numerous explorations have been focused on foaming factors and fermentation strategies, but a systematic summary and discussion are still lacking. Additionally, although these studies have not broken through the bottleneck of foaming, they are conducive to understanding the foaming mechanism and developing more effective rhamnolipids production strategies. Therefore, this review focuses on the effects of fermentation components and control conditions on foaming behavior and fermentation strategies responded to the severe foaming in rhamnolipids fermentation and systematically summarizes 6 impact factors and 9 fermentation strategies. Furthermore, the potentialities of 9 fermentation strategies for large-scale production are discussed and some further strategies are suggested. We hope this review can further facilitate the understanding of foaming factors and fermentation strategies as well as conducive to developing the more effective large-scale production strategies to accelerate the commercial production process of rhamnolipids.

scholarly journals Preventive maintenance policy on leasing by considering the usage rate

2018 ◽  
Vol 204 ◽  
pp. 02016
Author(s):  
Moh. Jufriyanto ◽  
Nani Kurniati ◽  
Ade Supriatna
Keyword(s):  
Preventive Maintenance ◽  
Failure Time ◽  
Equipment Failure ◽  
Maintenance Policy ◽  
Time Duration ◽  
Maintenance Costs ◽  
Operational Conditions ◽  
Penalty Cost ◽  
Usage Rate ◽  
Preventive Maintenance Policy

The needs of the consumers about the functionality of a product and increase maintenance costs of equipment caused the prices of products and treatments to be expensive. Therefore, the company considers the lease rather than buy it. Leasing provides interesting strategy when dealing with expensive equipment. Policy maintenance that is done to the product that has decreased performance. Minimum repair done to fix failed equipment in order to return to operational condition, while imperfect preventive maintenance to improve the operational conditions of the equipment to avoid failure. Time duration for a minimum repair neglected. The lessor will charge a penalty (penalty cost) if the lease equipment failure. Mathematical model built for the minimization cost of maintenance policy. In the final part, the numerical experiment are given to show the maintenance policy taking into account the rate of usage (usage rate) by knowing the minimization the resulting costs.

In vitro biomechanical comparison of load to failure testing of a canine unconstrained medial compartment elbow arthroplasty system and normal canine thoracic limbs

2013 ◽  
Vol 26 (05) ◽  
pp. 356-365 ◽  
Author(s):  
K. L. Wendelburg ◽  
S. Tepic ◽  
S. M. Stover ◽  
T. Garcia-Nolen ◽  
P. B. Stearns ◽  
...  
Keyword(s):  
Axial Load ◽  
Failure Modes ◽  
Ex Vivo ◽  
Medial Compartment ◽  
Elbow Arthroplasty ◽  
Total Arthroplasty ◽  
Significant Difference ◽  
Load To Failure ◽  
And Control

SummaryElbow dysplasia, primarily affecting the medial compartment, is the most common cause of lameness in the thoracic limb. Elbow arthroplasty is an option for end stage or severely affected patients. The purpose of this study was to compare ex vivo axial load to failure of an implanted novel elbow arthroplasty system to control limbs. The partial arthroplasty is a medial compartmental, unconstrained system, intended to allow conversion to total arthroplasty. We hypothesized that there would not be any significant difference between implanted and controlled limbs when loaded to failure. Six pairs of medium mixed breed canine cadaveric thoracic limbs were prepared for comparison of failure loading of control and implanted limbs. Axial compression was performed using a mechanical testing system. Failure loads were normalized to bodyweight. The mean normalized failure load (N/kg) for the implanted limbs and control limbs were 2.47 (range: 1.62-3.38) and 2.68 (range: 2.25-3.25), respectively. An implanted to control ratio of 0.93 ± 0.19 was calculated. The difference between paired control and implanted limbs in normalized failure loading was not significant (p = 0.38). There were not any differences noted in the yield load (p = 0.30), stiffness (p = 0.62), or energy (0.58). Failure modes were recorded. We concluded that the differences between implanted and control limbs in supra-physiologic axial load to failure were not significant.

scholarly journals Identity Management System Model in the Internet of Things

TEM Journal ◽  
2020 ◽  
pp. 1338-1347
Author(s):  
Belkacem Athamena ◽  
Zina Houhamdi
Keyword(s):  
Management System ◽  
Identity Management ◽  
User Requirements ◽  
Sequence Diagrams ◽  
Modelling Language ◽  
Unified Modelling Language ◽  
Defining System ◽  
Identity Management System ◽  
System Requirements ◽  
The Internet Of Things

This paper describes the identity management system (IdMS) by defining system and user requirements. Additionally, it introduces the IdMS concept that approaches the things identity management. Moreover, the paper deeply describes the IdMS features using unified modelling language (UML) diagrams such as class, system, and sequence diagrams to show the main system functionalities. Ultimately, the suggested system is evaluated by comparing it with the existing systems and discussing the fulfilment of user and system requirements.

Operation and Control of Microgrid

2019 ◽  
pp. 412-433
Author(s):  
Maheswari M. ◽  
Gunasekharan S.
Keyword(s):  
New Technologies ◽  
Operating Cost ◽  
Peak Load ◽  
Clean Energy ◽  
High Energy ◽  
Control Pattern ◽  
Micro Grid ◽  
Distribution Generation ◽  
And Control ◽  
Flexible Operation

The demand for electricity is increasing day by day due to technological advancements. According to the demand, the size of the grid is also increasing rapidly in the past decade. However, the traditional centralized power grid has many drawbacks such as high operating cost, customer satisfaction, less reliability, and security. Distribution generation has less pollution, high energy efficiency, and flexible installation than traditional generation. It also improves the performance of the grid in peak load and reliability of supply. The concept of micro-grid has been raised due to the advent of new technologies and development of the power electronics and modern control theory. Micro-grid is the significant part of the distribution network in the future of smart grid, which has advanced and flexible operation and control pattern, and integrates distributed clean energy.

scholarly journals Stability of Optimal Closed-Loop Cleaning Scheduling and Control with Application to Heat Exchanger Networks under Fouling

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1623
Author(s):  
Federico Lozano Santamaria ◽  
Sandro Macchietto
Keyword(s):  
Heat Exchanger ◽  
Closed Loop ◽  
Operating Cost ◽  
Optimization Procedure ◽  
Loop Model ◽  
Loop Scheduling ◽  
Loop Optimization ◽  
Trade Offs ◽  
Heat Exchanger Networks ◽  
And Control

Heat exchanger networks subject to fouling are an important example of dynamic systems where performance deteriorates over time. To mitigate fouling and recover performance, cleanings of the exchangers are scheduled and control actions applied. Because of inaccuracy in the models, as well as uncertainty and variability in the operations, both schedule and controls often have to be revised to improve operations or just to ensure feasibility. A closed-loop nonlinear model predictive control (NMPC) approach had been previously developed to simultaneously optimize the cleaning schedule and the flow distribution for refinery preheat trains under fouling, considering their variability. However, the closed-loop scheduling stability of the scheme has not been analyzed. For practical closed-loop (online) scheduling applications, a balance is usually desired between reactivity (ensuring a rapid response to changes in conditions) and stability (avoiding too many large or frequent schedule changes). In this paper, metrics to quantify closed-loop scheduling stability (e.g., changes in task allocation or starting time) are developed and then included in the online optimization procedure. Three alternative formulations to directly include stability considerations in the closed-loop optimization are proposed and applied to two case studies, an illustrative one and an industrial one based on a refinery preheat train. Results demonstrate the applicability of the stability metrics developed and the ability of the closed-loop optimization to exploit trade-offs between stability and performance. For the heat exchanger networks under fouling considered, it is shown that the approach proposed can improve closed-loop schedule stability without significantly compromising the operating cost. The approach presented offers the blueprint for a more general application to closed-loop, model-based optimization of scheduling and control in other processes.

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