Assessment of Heat Exchanger Degradation in a Boeing 737-800 Environmental Control System

2021 ◽  
Vol 13 (6) ◽  
Author(s):  
Ian Jennions ◽  
Fakhre Ali
Keyword(s):  
Control System ◽  
Heat Exchangers ◽  
Environmental Control ◽  
Strong Association ◽  
Cost Effective ◽  
Fault Isolation ◽  
Air Conditioner ◽  
Simulation Methodology ◽  
Working Together ◽  
Critical Fault

Abstract There are a number of systems on an aircraft working together, in harmony, to produce safe and trouble free flight. The environmental control system (ECS) is one of these systems, and its failure is a major contributor to unscheduled maintenance, particularly in older aircraft. The ECS is composed of several complex sub-systems and components, but at its heart is the passenger air conditioner (PACK). The PACK is prone to degradation, which can lead to the functional failure of the ECS. Often its degradation is masked by the overall ECS control system and this can, ultimately, result in the ECS shutting down and extensive maintenance being required. There are a number of critical fault modes associated with the PACK, and in this paper, those modes associated with the primary and secondary heat exchangers (SHX) are explored. A robust ECS simulation framework called Simscape ECS simulation under all conditions (SESAC) has previously been implemented, calibrated, and tested against data from healthy systems. Here the simulations are extended to cover degraded components in a representative Boeing 737-800 aircraft PACK model. Fault modes such as blockage and fouling are assessed for the primary and secondary heat exchangers of the PACK. Simulation results, in terms of temperature, pressure, and mass flow at various degradation severities, are presented and discussed. The results highlight the interdependency between the PACK components and the strong association between the primary and secondary heat exchangers performance. The reported simulation methodology and findings serve as a further step towards the goal of formulating a cost-effective ECS fault isolation and diagnostic solution.

scholarly journals Simulating faults in a Boeing 737-200 Environmental Control System using a thermodynamic model

2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Manuel Esperon-Miguez ◽  
Ian K. Jennions ◽  
Ignacio Camacho Escobar ◽  
Nile Hanov
Keyword(s):  
Control System ◽  
Control Systems ◽  
Thermodynamic Model ◽  
Heat Exchangers ◽  
Environmental Control ◽  
Aircraft Cabin ◽  
Civil Aircraft ◽  
Key Driver ◽  
Condition Monitoring System ◽  
Using Data

The Environmental Control Systems ( ECS ), used to provide air to the aircraft cabin at the correct pressure and temperature, is a key driver of maintenance interruptions for military and civil aircraft. Fault detection is particularly difficult, due to the lack of instrumentation and the ability of the ECS’s control system to mask symptoms. Understanding how component degradation affects measurable thermodynamic parameters is key to developing a condition monitoring system for an ECS. This work focuses on the development of a thermodynamic model of a Boeing 737-200 ECS capable of simulating faults in three types of component: heat exchangers, valves, and water separators. The thermodynamic model has been validated using data collected on a ground-based instrumented B737-200 ECS. The results show how a thermodynamic model can be used to simulate the change of temperatures and pressures across the ECS when components degrade.

Bayesian network method for fault diagnosis of civil aircraft environment control system

2019 ◽  
Vol 234 (5) ◽  
pp. 662-674
Author(s):  
Cui Liu ◽  
Jianzhong Sun ◽  
Fangyuan Wang ◽  
Shungang Ning ◽  
Guofan Xu
Keyword(s):  
Control System ◽  
Fault Diagnosis ◽  
Bayesian Network ◽  
Environmental Control ◽  
Fault Isolation ◽  
Commercial Aircraft ◽  
Extraction Technology ◽  
Data Set ◽  
Network Method ◽  
Environment Control

This paper addresses the issues of fault diagnosis of the environmental control system of a certain commercial aircraft model of which the environmental control system has a high failure rate in field and causes many unplanned maintenance events. Because of the complexity and reciprocal compensation mechanism of the environmental control system, it is difficult to carry out fault isolation timely once the failure occurred during aircraft turnaround time, which thus may cause flight delay or even cancelation. The original contribution of this work is to propose a Bayesian network–based fault diagnosis method for commercial aircraft environmental control system where a multi-information fusion mechanism is used to incorporate the system first principle, expert experience and condition monitoring data. It incorporates extraction technology of sensor feature parameters and the structural learning of Bayesian network to realize the effective diagnosis of multiple faults. A case study is conducted based on a data set from a commercial aircraft fleet. The results show that the fault isolation ratio of this method is greater than 89%. The proposed Bayesian fault diagnosis network method can be used as a troubleshooting tool for airline maintenance technicians in fault isolation of environmental control system, reducing the time spent on-line troubleshooting and aircraft downtime.

scholarly journals The Contribution of IoT to the Implementation of Preventive Conservation According to European Standards: The Case Study of the “Cannone” Violin and Its Historical Copy

2021 ◽  
Vol 13 (4) ◽  
pp. 1900
Author(s):  
Chiara Manfriani ◽  
Giovanni Gualdani ◽  
Giacomo Goli ◽  
Bruce Carlson ◽  
Anna Rita Certo ◽  
...  
Keyword(s):  
Control System ◽  
Environmental Control ◽  
Environmental Parameters ◽  
Cost Effective ◽  
Climate Data ◽  
Indoor Climate ◽  
Efficient System ◽  
Preventive Conservation ◽  
European Standards

One of the main goals of preventive conservation (PC) is to reduce the risk of possible damage produced by the interaction between tangible heritage objects and their conservation environments. This work aims to introduce the European standard EN 15757:2010 as a potential tool for implementing effective museum PC, and it details the potential contributions of both active environmental control and Internet of Things (IoT) technologies in this regard. An application of this strategy is proposed by means of a case study of the conservation of two historical violins, part of a small but significant museum collection in the City of Genoa dedicated to Paganini, whose value is inestimable. According to the standard, monitoring of environmental parameters was carried out for more than four years in the Paganini Hall of Palazzo Doria-Tursi Museum. A remote-control system was implemented, installing digital sensors in the room and in the two showcases. The data were continuously collected through an integrated platform for supervision, monitoring and shared management, based on web-cloud-IoT technology. The analysis of climate data and the assessment of the “historic climate” led to the installation of an active control system on the display cases of the “Cannone” violin and its historical copy. The intervention resulted in a cost-effective improvement in the conservation conditions of the two objects, with an efficient system of warning and safety alarms and a protocol of resolution actions still active and ongoing. The application of IoT systems in monitoring and controlling the indoor climate of heritage collections facilitated the care of the objects at a cost reduction for the institution.

A Sample Preparation on Decapsulation Methodology for Effective Failure Analysis on Thin Small Leadless (TSLP) Flip Chip Package with Copper Pillar (CuP) Bump Interconnect Technology

2014 ◽  
Author(s):  
Gwee Hoon Yen ◽  
Ng Kiong Kay
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Flip Chip ◽  
Fault Localization ◽  
Cost Effective ◽  
Fault Isolation ◽  
Voltage Contrast ◽  
Interconnect Technology

Abstract Today, failure analysis involving flip chip [1] with copper pillar bump packaging technologies would be the major challenges faced by analysts. Most often, handling on the chips after destructive chemical decapsulation is extremely critical as there are several failure analysis steps to be continued such as chip level fault localization, chip micro probing for fault isolation, parallel lapping [2, 3, 4] and passive voltage contrast. Therefore, quality of sample preparation is critical. This paper discussed and demonstrated a quick, reliable and cost effective methodology to decapsulate the thin small leadless (TSLP) flip chip package with copper pillar (CuP) bump interconnect technology.

Research on Intelligent Variable Frequency of Air-Conditioner Control System Based on Fuzzy Control

2011 ◽  
Vol 110-116 ◽  
pp. 4076-4084
Author(s):  
Hai Cun Du
Keyword(s):  
Neural Network ◽  
Control System ◽  
Fuzzy Control ◽  
Fuzzy Neural Network ◽  
Air Conditioner ◽  
Neural Network Controller ◽  
The Neural Network ◽  
Network Controller ◽  
Fuzzy Neural ◽  
Fuzzy Control Strategy

In this paper, we determine the fuzzy control strategy of inverter air conditioner, the fuzzy control model structure, the neural network and fuzzy control technology, structural design of the fuzzy neural network controller as well as the neural network predictor FNNC NNP. Simulation results show that the fuzzy neural network controller can control the accuracy greatly improved the compressor, and the control system has strong adaptability to achieve a truly intelligent; model of the controller design and implementation of technology are mainly from the practical point of view, which is practical and feasible.

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