scholarly journals ANN-based Classification of Operating Data in Humid Air-Water Heat Exchangers

2021 ◽  
Author(s):  
Gabriela Avila ◽  
Arturo Pacheco-Vega
Keyword(s):  
Heat Exchangers ◽  
Humid Air ◽  
Operating Data

scholarly journals POLYMERS AND PLASTIC USE FOR THE HEAT-EXCHANGE EQUIPMENT (REVIEW)

2020 ◽  
pp. 59-71
Author(s):  
I.O. Mikulionok
Keyword(s):  
Heat Exchange ◽  
Heat Exchangers ◽  
Polymeric Materials ◽  
Strength Properties ◽  
Polymers And Plastics ◽  
Heat Exchange Equipment ◽  
Coefficient Of Heat Conductivity ◽  
Exchange Apparatus ◽  
Polymer Type

The possibility of use of the heat-exchangers in whole or in part manufactured with use of polymers and plastics is considered. Despite obvious, at first sight, inexpediency of use of polymeric materials in the heat-exchange equipment (low coefficient of heat conductivity, and also low, in comparison with metals, the strength properties of the majority of the most widespread polymers), «polymeric» heat-exchangers find application in various areas of the industry more and more surely. Classification of heat-exchange apparatuses which constructive elements are executed with use of polymeric materials is proposed. The following signs are the basis for classification: polymer type, a type of polymer meric material, type of the heat-exchange apparatus (a form of heat-exchange elements), reliance on polymeric materials in apparatuses, motion freedom of polymeric heat-exchange elements, level of assembly of a design, and also diameter of tubular elements. Critical analysis the most characteristic designs developed by domestic and foreign designers and inventors is carried out. Ref. 21, Fig. 13.

Design Study of a Humidification Tower for the Advanced Humid Air Turbine System

2005 ◽  
Author(s):  
Hidefumi Araki ◽  
Shinichi Higuchi ◽  
Shinya Marushima ◽  
Shigeo Hatamiya
Keyword(s):  
Gas Turbine ◽  
Heat Exchangers ◽  
High Efficiency ◽  
Cooling System ◽  
Pressure Ratio ◽  
Humid Air ◽  
Air Turbine ◽  
Water Atomization ◽  
Air Cooler ◽  
Compressor Work

The AHAT (advanced humid air turbine) system, which can be equipped with a heavy-duty, single-shaft gas turbine, aims at high efficiency equal to that of the HAT system. Instead of an intercooler, a WAC (water atomization cooling) system is used to reduce compressor work. The characteristics of a humidification tower (a saturator), which is used as a humidifier for the AHAT system, were studied. The required packing height and the exit water temperature from the humidification tower were analyzed for five virtual gas turbine systems with different capacities (1MW, 3.2MW, 10MW, 32MW and 100MW) and pressure ratios (π = 8, 12, 16, 20 and 24). Thermal efficiency of the system was compared with that of a simple cycle and a recuperative cycle with and without the WAC system. When the packing height of the humidification tower was changed, the required size varied for the three heat exchangers around the humidification tower (a recuperator, an economizer and an air cooler). The packing height with which the sum total of the size of the packing and these heat exchangers became a minimum was 1m for the lowest pressure ratio case, and 6m for the highest pressure ratio case.

Classification of Heat Exchangers

2020 ◽  
pp. 1-27
Author(s):  
Sadık Kakaç ◽  
Hongtan Liu ◽  
Anchasa Pramuanjaroenkij
Keyword(s):  
Heat Exchangers

scholarly journals Icing control model and algorithm for wasteheat exchangers of ventilation systems

2018 ◽  
Vol 194 ◽  
pp. 01004
Author(s):  
Аndrew Arbatskiy ◽  
Аndrew Garyaev ◽  
Vasiliy Glasov
Keyword(s):  
Mathematical Model ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Control Model ◽  
Humid Air ◽  
Exchange Apparatus ◽  
Ice Control

Currently, ice control on various heat exchangers to be used for waste heat recovery of discharge air is a rather topical subject because ice building is a factor to reduce efficiency of heat recovery. In such systems, icing always takes place on the side of humid discharge air, with a background of heat exchange between inlet air at temperatures of -30°C and below, and discharge air. To effectively prevent this, it is required to find solutions to problems as follows: study a mechanism of ice building on heat exchange surfaces when interacting with humid air; determine engineering methods to prevent icing, for each type of heat-exchange apparatus, and check efficiency of their operation; develop a mathematical model of ice growth on heat exchange surfaces to enable to vary key parameters (both geometrical and algorithmical ones), determined beforehand, and engineering means aimed at icing prevention.

Heat Rate Predictions in Humid Air-Water Heat Exchangers Using Correlations and Neural Networks

2000 ◽  
Vol 123 (2) ◽  
pp. 348-354 ◽  
Author(s):  
Arturo Pacheco-Vega ◽  
Gerardo Dı´az ◽  
Mihir Sen ◽  
K. T. Yang ◽  
Rodney L. McClain
Keyword(s):  
Neural Network ◽  
Heat Transfer ◽  
Heat Exchangers ◽  
Heat Rate ◽  
Humid Air ◽  
Compact Heat Exchangers ◽  
The Neural Network ◽  
Fin Tube ◽  
Experimental Values ◽  
Comparison Of The Results

We consider the flow of humid air over fin-tube multi-row multi-column compact heat exchangers with possible condensation. Previously published experimental data are used to show that a regression analysis for the best-fit correlation of a prescribed form does not provide an unique answer, and that there are small but significant differences between the predictions of the different correlations thus obtained. It is also shown that it is more accurate to predict the heat rate directly rather than through intermediate quantities like the j-factors. The artificial neural network technique is offered as an alternative technique. It is trained with experimental values of the humid-air flow rates, dry-bulb and wet-bulb inlet temperatures, fin spacing, and heat transfer rates. The trained network is then used to make predictions of the heat transfer. Comparison of the results demonstrates that the neural network is more accurate than conventional correlations.

scholarly journals Suitability of combined sewers for the installation of heat exchangers

2016 ◽  
Vol 23 (1) ◽  
pp. 87-98
Author(s):  
David Stransky ◽  
Ivana Kabelkova ◽  
Vojtech Bares ◽  
Gabriela Stastna ◽  
Zbigniew Suchorab
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Classification Scheme ◽  
Flow Characteristics ◽  
Economic Conditions ◽  
Sewer System ◽  
Biofilm Growth ◽  
Flow Modelling ◽  
Hydraulic Conditions

AbstractThe present paper deals with the classification of the suitability of combined sewers for the installation of heat exchangers and with assessment of the theoretical potential of wastewater in the sewer system for heating of buildings. A classification scheme involving criteria like theoretically available heat, sewer diameter, number of the heat exchanger parallel modules in the sewer cross-section, hydraulic conditions (hydraulic capacity of the sewer, pressurized flow), and potential fouling by biofilm growth was developed. First, individual sewers in the pilot catchment were assessed based on monitoring the flow characteristics and wastewater temperatures and on pipe flow modelling. Second, connectivity of the suitable and partly suitable sewers was examined with respect to the length necessary for the installation of the heat exchanger with the minimum required power of 100 kW. For the continuous sewer sections, the maximum potential power was calculated. The presented approach is generally applicable, however, for other heat exchanger types and other climatic and economic conditions, values of the suitability criteria for the heat exchanger installation must be adapted.

Classification of Condensing Heat Exchangers Performance Data by Gaussian Mixtures

2009 ◽  
Author(s):  
Arturo Pacheco-Vega ◽  
Gabriela Avila
Keyword(s):  
Experimental Data ◽  
Neural Networks ◽  
Heat Exchangers ◽  
Clustering Algorithm ◽  
Gaussian Mixture ◽  
Film Condensation ◽  
Gaussian Mixtures ◽  
Independent Evaluation ◽  
Condensing Heat Exchanger

We introduce a methodology to extract the regimes of operation from condensing heat exchanger data. The methodology uses a Gaussian mixture clustering algorithm to determine the number of groups from the data, and a maximum likelihood decision rule to classify the data into these clusters. In order to assess the accuracy of clustering technique, experimental data from the literature visually classified as dry-surface, dropwise condensation, and film condensation, are used in the analysis. Though there is a discrepancy between the clustering classification and the visual one, an independent evaluation using artificial neural networks (ANNs) shows that the clustering methodology is able to both find the different regimes of operation and classify the data corresponding to each regime.

scholarly journals A Review of CFD Analysis of Heat Exchanger for Laminar Flow

2021 ◽  
Vol 7 (3) ◽  
pp. 9-12
Author(s):  
Ravi Shankar Kumar ◽  
D.S. Chauhan
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Manufacturing Industry ◽  
Waste Heat ◽  
Industrial Applications ◽  
Compact Structure ◽  
Environmental Technology ◽  
Computational Fluids ◽  
Heat Transfer Capacity

Helical coil heat exchangers, due to their maturity, are widely used in industrial applications such as the chemical and food industry, power generation, electronics, environmental technology, manufacturing industry, air conditioning, waste heat recovery, etc. on straight and cup heat exchangers. With its compact structure, larger heat transfer area and higher heat transfer capacity, etc., the twisted tap and classification of improvement techniques are presented in this paper. To present the dynamics, application, and advantages of CFD for computational fluids presented in this paper.

scholarly journals Applications of Heat Transfer Enhancement Techniques: A State-of-the-Art Review

2020 ◽  
Author(s):  
Suvanjan Bhattacharyya ◽  
Devendra K. Vishwakarma ◽  
Sanghati Roy ◽  
Ranjib Biswas ◽  
Mohammad Moghimi Ardekani
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Heat Exchangers ◽  
Vortex Generators ◽  
Transfer Enhancement ◽  
Heat Transfer Augmentation ◽  
Roughness Elements ◽  
Basic Concepts ◽  
The Individual

The fundamentals of heat transfer and its applications, the classification of heat transfer technology and different heat transfer techniques, and the needs for augmentation and its benefits and the different combinations of two or more inserts and integral roughness elements for heat transfer augmentation purpose have been introduced and discussed in this chapter. It is shown that most of the compound techniques performed better than the individual inserts for heat transfer enhancement. This chapter has also been dedicated to understanding the basic concepts of vortex generators for heat transfer enhancement in plate-fin heat exchangers. The performance of transverse, longitudinal, and wing-type vortex generators has been discussed as well.

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