Integration of vehicle, propulsion system and separation unit designs for a launcher using in-flight oxygen collection

in AIAA/CIRA 13th International Space Planes and Hypersonics Systems and Technologies Conference (2005, May)

The use of in-flight Oxygen Collection has shown to significantly improve space launcher performance. The conceptual approach followed by the Royal Military Academy of Brussels (RMA) has tried to widen ... [more ▼]

The use of in-flight Oxygen Collection has shown to significantly improve space launcher performance. The conceptual approach followed by the Royal Military Academy of Brussels (RMA) has tried to widen the available design margins in order to reduce the required technological leap and limit the economical risk associated with such a development. The aim of the ESA-funded theoretical and experimental study on an air separation device is to demonstrate the possibility of performing efficient air distillation in a compact rotating column. An integration of the vehicle, propulsion system and separation unit designs is presented aiming to optimise the overall vehicle performance while keeping technological difficulty and system complexity at a reasonable level. Reference vehicles are presented in their specific mission profiles with an emphasis on TSTO’s. Different layouts of the internal energy and mass flowsheets are compared, in order to make best use of the refrigeration capacity of the hydrogen fuel running though the propulsion system during the first phase of the flight considering the separator as a classical distillation column. This analysis provides the requirements in terms of heat exchange capacity, compression ratios and number of so-called transfer units needed in the separator. Here, the system is intentionally kept simple, to limit complexity, but the analysis is thorough and accurate, including, for example, the effect of the presence of argon. An analysis of the separation unit to reach those requirements is proposed. That includes internals, practical building with estimates of pressure drop, separation performance and flow limitation. Analysis of size reduction of the distillation unit from usual 1-g column to the high-g unit is provided as well as the scale up methodology of laboratory results. First experimental results obtained with our centrifugally enhanced distillation separation system are presented and perspectives for a larger on-board operational unit proposed. [less ▲]

Use of Parallel Computers in Rational Design of Redundant Sensor Networks

(2004, May 16)

Data reconciliation and sampling protocol design, case of a paper deinking process

in Paperi Ja Puu-Paper and Timber (2004), 86(8), 565-570

An equation solver data reconciliation software has been used to build a validated model of a waste paper deinking mill, by combining control room measurements and process design specifications. An ... [more ▼]

An equation solver data reconciliation software has been used to build a validated model of a waste paper deinking mill, by combining control room measurements and process design specifications. An optimal sampling protocol to validate the model by using only control room measurements has been determined by identifying, with genetic algorithm programming, the additional sampling points and corresponding sensors required to compensate for the lack of redundant measurements. [less ▲]

How CAPE tools can contribute to process sustainability

in Journal of Cleaner Production (2004), 12(2), 117-124

The concern of the EFCE for sustainability. Four recent case studies to illustrate how CAPE tools contribute to process sustainability: (1) ultimate plant operation at Wacker-Chemie (DE), (2) development ... [more ▼]

The concern of the EFCE for sustainability. Four recent case studies to illustrate how CAPE tools contribute to process sustainability: (1) ultimate plant operation at Wacker-Chemie (DE), (2) development of a new sulphuric acid plant with Air Liquide (FR), (3) plant retrofit for CO2 abatement at Kemira (BE), (4) insertion of a new plant in an existing Solvay industrial site (Asia). (C) 2003 Published by Elsevier Ltd. [less ▲]

Mathematical modelling and design of an advanced once-through heat recovery steam generator

in Computer Aided Chemical Engineering (2003), 14

The once-through heat recovery steam generator design is ideally matched to very high temperature and pressure, well into the supercritical range. Moreover this type of previous termboilernext term is ... [more ▼]

The once-through heat recovery steam generator design is ideally matched to very high temperature and pressure, well into the supercritical range. Moreover this type of previous termboilernext term is structurally simpler than a conventional one, since no drum is required. A specific mathematical model has been developed. Thermodynamic model has been implemented to suit very high pressure (up to 240 bar), sub- and supercritical steam properties. We illustrate the model use with a 180 bar once-through previous termboilernext term (OTB). [less ▲]

Computer-Aided Design of Redundant Sensor Networks

Poster (2002, May)

A systematic method to design sensor networks able to identify key process parameters with a required precision at a minimal cost is presented. The procedure is based on a linearised model, derived ... [more ▼]

A systematic method to design sensor networks able to identify key process parameters with a required precision at a minimal cost is presented. The procedure is based on a linearised model, derived automatically from a rigorous non-linear data reconciliation model. A genetic algorithm is used to select the sensor types and locations. [less ▲]

Modelling the butterfat crystallisation process

in Computers & Chemical Engineering (1999), 23(Suppl. S), 819-822

Milk fat exhibits seasonal variations in composition and properties which are undesirable for many subsequent applications. Thus techniques are sought to process dairy products in order to achieve a ... [more ▼]

Milk fat exhibits seasonal variations in composition and properties which are undesirable for many subsequent applications. Thus techniques are sought to process dairy products in order to achieve a consistent quality. A brief introduction to milk fat presents its most important particularities, especially composition, seasonal variations, solid fat content, crystalisation and polymorphism. The differential scanning calorimetry (DSC) analysis allows to estimate the solid fat content. Different methods have been developed to estimate more and more precisely the solid fat content which is certainly an important parameter in the description of the textural properties of butterfat. The industrial crystallisation process is modelled on the basis of pilot plant data. That model allows to approach the particular temperature profile in the scraped surface heat exchangers and to give a first explanation of the involved phenomena. [less ▲]

Spreadsheet based teaching aids in chemical engineering education

in Computers & Chemical Engineering (1999), 23(Suppl. S), 629-632

Modern spreadsheet programs offer a wide range of calculation, charting and dialog options, allowing the development of effective teaching aids. Examples of worksheet illustrating numerical analysis ... [more ▼]

Modern spreadsheet programs offer a wide range of calculation, charting and dialog options, allowing the development of effective teaching aids. Examples of worksheet illustrating numerical analysis, thermodynamics and unit operations are shown. All offer complete interaction between the problem statement and the presentation of results. [less ▲]

A comparison of advanced thermal cycles suitable for upgrading existing power plants

in Applied Thermal Engineering (1998), 19

Energy savings in methanol synthesis: Use of heat integration techniques and simulation tools.

in Computers & Chemical Engineering (1997), 21(Suppl. S), 511-516

Starting with a classical process for producing methanol using the reforming and synthesis steps, a combined approach applying simulation models and a new synthesis strategy, named Effect Modelling and ... [more ▼]

Starting with a classical process for producing methanol using the reforming and synthesis steps, a combined approach applying simulation models and a new synthesis strategy, named Effect Modelling and Optimisation (EMO), has been used to optimise the energy efficiency of the process. The method allows to identify different ways of improving the energy efficiency of the process. The modifications concern the synthesis reactor and the reforming reactor designs, the exploitation of the purge stream as fuel gas to satisfy the process requirement and its integration to a gas turbine system. The EMO approach allows to target the impact of a process modification at the global level of the energy cost of the process, including the combined production of heat and mechanical power in a gas turbine and the steam network. Starting with a classical methane conversion of 60% for the classical system, we identify solutions with up to 93% of the overall methane conversion when we transform the net mechanical power produced into methane savings at the country level. The interest of the approach is the possibility of computing the impact of the process modifications suggested by the analysis of the shape of the heat cascade on the overall energy balance of the plant without having to simulate in many details the steam and the heat exchanger network. [less ▲]