Dynamic Models of Heat Exchangers Under Restrictions of Computational Resources

The article is dedicated to a design of a pilot model of a 60 MW installation, operating according to a new promising compressorless combined cycle. In the course of the study, the weight-size parameters and functional indicators of the main parts of the energy complex were preliminarily determined. The auxiliary components of a compressorless combined cycle unit were selected, such as pumps, heat exchangers, compressors, pipelines and etc. Within a draft elaboration, preliminary weight, size and functional parameters of a turbine unit were defined, solutions were found for two groups of pumping equipment, and a plant prototype was designed. Additionally, the weight and size parameters of the plate heat exchangers were determined and a special design of shell-and-tube heat exchangers was designed to return the heat of combustion products. The results, obtained during the study, make it possible to simulate the behavior (develop dynamic models) of a compressorless combined cycle unit in all operating modes (from start-up to shutdown) under various conditions, as well as to carry out a feasibility study for the creation of such installations.

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Classification and Recommendation With Data Streams

Encyclopedia of Information Science and Technology, Fifth Edition - Advances in Information Quality and Management ◽

10.4018/978-1-7998-3479-3.ch047 ◽

2021 ◽

pp. 675-684

Author(s):

Bruno Veloso ◽

João Gama ◽

Benedita Malheiro

Keyword(s):

Social Networks ◽

Internet Of Things ◽

Data Streams ◽

Exponential Growth ◽

Data Stream ◽

Dynamic Models ◽

Model Updating ◽

Online Classification ◽

Personal Mobile Devices ◽

Computational Resources

Nowadays, with the exponential growth of data stream sources (e.g., Internet of Things [IoT], social networks, crowdsourcing platforms, and personal mobile devices), data stream processing has become indispensable for online classification, recommendation, and evaluation. Its main goal is to maintain dynamic models updated, holding the captured patterns, to make accurate predictions. The foundations of data streams algorithms are incremental processing, in order to reduce the computational resources required to process large quantities of data, and relevance model updating. This article addresses data stream knowledge processing, covering classification, recommendation, and evaluation; describing existing algorithms/techniques; and identifying open challenges.

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Introducing Thermolab: a toolbox for Thermodynamics in MATLAB

10.5194/egusphere-egu2020-20069 ◽

2020 ◽

Author(s):

Johannes C. Vrijmoed ◽

Yury Y. Podladchikov

Keyword(s):

Gibbs Energy ◽

Dynamic Models ◽

Equilibrium Phase ◽

Transport Processes ◽

Optimization Techniques ◽

Equilibrium Thermodynamic ◽

Gibbs Energies ◽

Thermodynamic Databases ◽

Computational Resources ◽

Non Equilibrium

We present a set of MATLAB codes that can be used to perform equilibrium and non-equilibrium thermodynamic calculations. This will be of general use in geomaterial research and education, from the calculation of equilibrium phase diagrams to the development of dynamic models of reaction, deformation, mass and heat transport processes. The main MATLAB function calculates Gibbs energies of pure substances and mixtures using internally consistent thermodynamic databases, for rocks, minerals, melts and fluids. A general formulation of calculating Gibbs energy of mixtures based on linear algebra allows users to add custom solution models in an easy manner. The main Gibbs energy function can also be further extended, updated and customized, for example to involve other thermodynamic databases and equations of state.We show three methods on how these Gibbs energies can be used to calculate chemical equilibrium based on optimization techniques and linear programming: 1) A brute-force method in which Gibbs energies of all possible phases and solutions are generated as a set of discrete phases. 2) A method of refining and restricting the Gibbs energies of solution phases to save computational resources and 3) A method that further saves computational resources by using system composition to generate Gibbs energies of solutions in a subset of the compositional space.Finally, we demonstrate how these codes can be used in non-equilibrium thermodynamic processes such as reactive-fluid flow involving density and porosity changes.

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Dynamic models of heat exchangers

Chemistry and Technology of Fuels and Oils ◽

10.1007/s10553-006-0022-2 ◽

2006 ◽

Vol 42 (1) ◽

pp. 25-29 ◽

Cited By ~ 6

Author(s):

N. M. Abbasov ◽

R. I. Zeinalov ◽

O. M. Azizova ◽

S. N. Imranova

Keyword(s):

Heat Exchangers ◽

Dynamic Models

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Physics-Based Dynamic Models of Three SOFC/GT Emulator Test Rigs

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4038152 ◽

2017 ◽

Vol 140 (5) ◽

Cited By ~ 3

Author(s):

Iacopo Rossi ◽

Alberto Traverso ◽

Martina Hohloch ◽

Andreas Huber ◽

David Tucker

Keyword(s):

Dynamic Modeling ◽

Dynamic Models ◽

Modeling Approach ◽

Control Scheme ◽

Advanced Control ◽

Model Tuning ◽

German Aerospace ◽

Computational Resources ◽

Near Future ◽

Dynamic Phenomena

This paper presents the development, implementation, and validation of a simplified dynamic modeling approach to describe solid oxide fuel cell gas turbine (SOFC/GT) hybrid systems (HSs) in three real emulator test rigs installed at University of Genoa (Italy), German Aerospace Center (DLR, Germany), and National Energy Technology Laboratory (NETL, USA), respectively. The proposed modeling approach is based on an experience-based simplification of the physical problem to reduce model computational efforts with minimal expense of accuracy. Traditional high fidelity dynamic modeling requires specialized skills and significant computational resources. This innovative approach, on the other hand, can be easily adapted to different plant configurations, predicting the most relevant dynamic phenomena with a reduced number of states: such a feature will allow, in the near future, the model deployment for monitoring purposes or advanced control scheme applications (e.g., model predictive control). The three target systems are briefly introduced and dynamic situations analyzed for model tuning, first, and validation, then. Relevance is given to peculiar transients where the model shows its reliability and its weakness. Assumptions introduced during model definition for the three different test rigs are discussed and compared. The model captured significant dynamic behavior in all analyzed systems (in particular those regarding the GT) and showed influence of signal noise on some of the SOFC computed outputs.

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Dynamic models for heat exchangers and heat exchanger networks

Computers & Chemical Engineering ◽

10.1016/0098-1354(94)80075-8 ◽

1994 ◽

Vol 18 ◽

pp. S459-S463 ◽

Cited By ~ 28

Author(s):

Knut W. Mathisen ◽

Manfred Morari ◽

Sigurd Skogestad

Keyword(s):

Heat Exchanger ◽

Heat Exchangers ◽

Dynamic Models ◽

Heat Exchanger Networks

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Experimental Study of the Variation Dynamic’s for Air Heat Exchanger

Mokslas - Lietuvos ateitis ◽

10.3846/mla.2017.1047 ◽

2017 ◽

Vol 9 (3) ◽

pp. 297-301

Author(s):

Maryia Marozava ◽

Dzmitry Hryniuk

Keyword(s):

Heat Exchanger ◽

Heat Exchangers ◽

Dynamic Models ◽

Management Systems ◽

Stabilization System ◽

Technological Parameters ◽

Control Loops ◽

The Stability

The development of management systems is assigned one of the leading roles. When solving the problems of regulating the technological parameters, various problems arise. One of such problems is the adjustment of control loops. For some control objects, one-time adjustment of the controller parameters can be made, and then it is periodically refined as necessary. In other objects, the changes occur very quickly, but in a certain range. In the latter case, you should first estimate the range of changes. Then find universal robust settings that will ensure the stability and quality of the stabilization system. Some of such objects are air heat exchangers. The article presents the results of the determination of the heat exchanger dynamics. The limits of the variation of the parameters of the dynamic models are determined. There is a significant nonlinearity in the transfer function of the control channel.

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Study of Height Influence of Heat Exchanger Tanks on Overall Pressure Drop

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.659.446 ◽

2014 ◽

Vol 659 ◽

pp. 446-449

Author(s):

Alexandru Rus ◽

Vlad Martian ◽

Mihai Nagi

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Heat Exchanger ◽

Pressure Drop ◽

Heat Exchangers ◽

Structural Complexity ◽

Complex Models ◽

Water Cooler ◽

Computational Resources ◽

Viable Method

In the context of a constant demand of more compact and efficient heat exchangers, the need for thoroughly researching the influence of the construction parameters impact on heat exchanger's performances arises. The purpose of the paper is to present the numerical results of such a research, carried out at RAAL S.A. with the support of "Politehnica" University of Timişoara. The research consists of assessing the effects of the geometric characteristics, the height in particular, of the inlet and outlet tanks of a water cooler on overall pressure drop, through Computational Fluid Dynamics. The structural complexity of heat exchangers demands that the analysis be divided into multiple, less complex models, in order to achieve accurate and truthful results within a reasonable amount of time and use of computational resources. The paper also focuses on developing a viable method for accomplishing numerical analyses on heat exchangers' parameters.

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Physics Based Dynamic Models of Three SOFC/GT Emulator Test-Rigs

Volume 3: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration Applications; Organic Rankine Cycle Power Systems ◽

10.1115/gt2017-64204 ◽

2017 ◽

Cited By ~ 2

Author(s):

Iacopo Rossi ◽

Alberto Traverso ◽

Martina Hohloch ◽

Andreas Huber ◽

David Tucker

Keyword(s):

Dynamic Models ◽

Dynamic Modelling ◽

Modeling Approach ◽

Control Scheme ◽

Advanced Control ◽

Model Tuning ◽

German Aerospace ◽

Computational Resources ◽

Near Future ◽

Dynamic Phenomena

This paper presents the development, implementation and validation of a simplified dynamic modeling approach to describe SOFC/GT hybrid systems in three real emulator test-rigs installed at University of Genoa (UNIGE, Italy), German Aerospace Center (DLR, Germany) and National Energy Technology Laboratory (NETL, USA), respectively. The proposed modeling approach is based on an experience-based simplification of the physical problem to reduce model computational efforts with minimal expense of accuracy. Traditional high fidelity dynamic modelling requires specialized skills and significant computational resources. This innovative approach, on the other hand, can be easily adapted to different plant configurations, predicting the most relevant dynamic phenomena with a reduced number of states: such a feature will allow, in the near future, the model deployment for monitoring purposes or advanced control scheme applications (e.g. model predictive control). The three target systems are briefly introduced and dynamic situations analyzed for model tuning, first, and validation, then. Relevance is given to peculiar transients where the model shows its reliability and its weakness. Assumptions introduced during model definition for the three different test-rigs are discussed and compared. The model captured significant dynamic behavior in all analyzed systems (in particular those regarding the GT) and showed influence of signal noise on some of the SOFC computed outputs.

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