scholarly journals Transient detection of either maldistribution or flowrate change in a counter current plate-fin heat exchanger using an ARX model

2022 ◽  
Vol 182 ◽  
pp. 121987
Author(s):  
Benoît Pfortner ◽  
Waseem Al Hadad ◽  
Vincent Schick ◽  
Denis Maillet ◽  
Célien Zacharie ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Transient Detection ◽  
Arx Model ◽  
Counter Current

scholarly journals The range of application of ORC power plant in power stations fed with low and medium thermal sources

2018 ◽  
Vol 70 ◽  
pp. 01009
Author(s):  
Tomasz Kujawa ◽  
Władysław Nowak
Keyword(s):  
Heat Exchanger ◽  
Power Plant ◽  
Rankine Cycle ◽  
Calculation Algorithm ◽  
Power Stations ◽  
Working Medium ◽  
Thermodynamic Transformations ◽  
Thermal Sources ◽  
Counter Current ◽  
Circuit Power

The work presents the diagrams of the applied power plant solutions with a description of their operation and calculation algorithm. In the latter case, the cycle of thermodynamic transformations of the Rankine cycle presented in the T-s coordinate system was used, which reflects the subsequent transformations occurring in individual devices of the power plant, including the method of determining unit quantities characterizing their operation. The energy balance equations of the evaporator and the heater are presented, which among other things will be the basis for determining the coefficient that plays an important role in determining the range of applications of the single-circuit sub-critical power plant in the power plant/CHP plant. The coefficient ϕ was defined as the ratio of the mass stream of water flowing through the counter-current heat exchanger in which the liquid of the working medium is heated within the limits of condensation and evaporation temperatures, to the mass stream of water leaving the evaporator according to the dependence ϕ = ṁs1/ṁs. It has been assumed that a given mass stream of water ṁs at a given temperature Ts1 is heated in a heat exchanger which is the upper heat source. The calculations of the power plant for selected working fluids (R227ea, RC318, R1234ze and R1234yf) were made for different evaporation temperatures taking into account near-subcritical temperatures for selected supply water temperatures. On this basis, the figures ϕ = f(TEVAP) illustrating the application ranges of a single-circuit power plant in a power plant/CHP plant were drawn up. The analysis of the above figures became the basis for formulating final conclusions.

Detailed Design Optimisation of Three-Fluid Parallel-Flow Plate-Fin Heat Exchanger Using Second Law Analysis

2020 ◽  
Author(s):  
Harpreet Kaur Aasi ◽  
Manish Mishra
Keyword(s):  
Heat Exchanger ◽  
Entropy Generation ◽  
Current Flow ◽  
Parallel Flow ◽  
Operating Conditions ◽  
Continuous Variables ◽  
Minimum Entropy ◽  
Louvered Fin ◽  
Counter Current Flow ◽  
Counter Current

Abstract Three-fluid compact heat exchanger of plate-fin type with parallel-flow configuration is optimised for the entropy generation. Four different types of plate fins (plain rectangular, offset strip, corrugated louvered and wavy fin) are embodied within heat exchanger for both co-current and counter-current flow arrangements have been selected for the study. Genetic algorithm is selected as an optimisation tool having apt in handling various continuous variables and discrete variables and the problems with complexities in the objective function as well as in constraints. Validation of the optimization model is carried out by comparing the results with that from experimental results, Particle swarm optimization (without heat duty constraint) and from graphical method (with heat duty constraint). It is observed that for a specified heat duty and given operating conditions corrugated louvered fin with counter-current flow arrangement offers the minimum entropy generation amongst all.

A Novel Gas-Water Heat Exchanger With Minichannels

2008 ◽  
Author(s):  
Yang Chen ◽  
Per Lundqvist ◽  
Bjo¨rn Palm
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Low Pressure ◽  
Shell Side ◽  
Hot Air ◽  
Drop Flow ◽  
Counter Current ◽  
Good Heat ◽  
Current Heat

In the current study, a novel gas water heat exchanger with minichannels is designed, built and tested. The heat exchanger is mainly composed of a number of concentric ring shaped plates, which are made up of several heat exchanger tubes. The ring shaped plates are arranged in parallel and placed in a shell. The heat exchanger is designed as a counter current heat exchanger with laminar flow on the heat exchanger’s shell-side (gas side) and therefore has a very low pressure drop on the shell side. The heat exchanger was tested with water and hot air on its tube-side and shell-side respectively. All the necessary parameters like inlet and outlet temperatures on tube-side and shell-side as well as the pressure drop, flow rate of fluids, etc. were measured. Different existing correlations were used to calculate the overall heat transfer coefficient and the results were compared with the measured value. The measured results show that the new designed heat exchanger can achieve a good heat transfer performance and also maintain a low pressure drop on shell-side (gas side).

scholarly journals PDE Observer Design for Counter-Current Heat Flows in a Heat-Exchanger

2017 ◽  
Vol 50 (1) ◽  
pp. 7127-7132 ◽  
Author(s):  
Fairouz Zobiri ◽  
Emmanuel Witrant ◽  
François Bonne
Keyword(s):  
Heat Exchanger ◽  
Observer Design ◽  
Heat Flows ◽  
Counter Current ◽  
Current Heat

scholarly journals The effect of meal temperature on heart rate in Rhodnius prolixus

2019 ◽  
Author(s):  
Chloé Lahondère ◽  
Maurane Buradino ◽  
Claudio R. Lazzari
Keyword(s):  
Heart Rate ◽  
Heat Exchanger ◽  
Rhodnius Prolixus ◽  
List Type ◽  
Meal Intake ◽  
Warm Blood ◽  
Counter Current ◽  
The Impact ◽  
Current Heat

AbstractRhodnius prolixus is able to cool down the ingested blood during feeding on a warm-blooded host. This is possible because of a counter-current heat exchanger located in its head, which transfers heat from the warm blood to the insect haemolymph and can dissipate through the head cuticle. Given the key role haemolymph circulation in thermoregulation, we investigated the modulation of the activity of the heart during the warmed meal intake. We evaluated the impact of meal temperature on the heart rate and found that feeding led to an increase in the frequency of heart contractions, which increases with increasing food temperature. We also found that females have a higher heart rate during feeding compare to males.HIGHLIGHTSFeeding increases the heart rate of Rhodnius prolixusThe higher the meal temperature, the higher the heart rate becomesFemales have a higher heart rate than males

scholarly journals RESEARCH OF THE FUNCTIONING AND OPTIMIZATION PROCESS OF THE STRUCTURAL-TECHNOLOGICAL PARAMETERS

2020 ◽  
pp. 142-150
Author(s):  
Vitaliy Yaropud
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Thermal Power ◽  
Design Parameters ◽  
Theoretical Studies ◽  
Technological Parameters ◽  
Air Flows ◽  
Counter Current ◽  
Pipe Heat

Domestic and foreign scientists in recent years have performed a considerable amount of scientific research on the biological justification of optimal combinations of microclimate parameters required for the normal development of animals. However, the results of the studies do not allow one to specify the optimal parameters for different species of animals, taking into account their age, sex, weight and level of feeding. While it is possible to specify rather wide limits of change of temperature and relative humidity of air at which productivity is maximum, and technical and economic efficiency is approximately the same. Providing microclimate regulations in livestock premises is associated with significant costs of electricity and heat, which is about 17% of the producers' costs. To create a microclimate in livestock premises based on the above technological parameters and the analysis of the design features of the recuperators, two design and technological schemes of the three-pipe recuperator, which differ in the directions of movement of air flows, are proposed. The purpose of the research is to increase the efficiency of the technological process of functioning of the three-pipe recuperator for livestock premises by substantiating its structural and mode parameters. The results of theoretical studies of pneumatic losses in the three-pipe recuperator determined the dependence of pressure and power losses on the length of the air duct of the three-pipe recuperator, the radius of the external duct and the volume flow rate of air. As a result of theoretical studies, a mathematical model of the heat transfer process in a three-pipe heat exchanger was developed, with condensation in it, which allows to determine the temperature distribution of air flows by its length and its thermal capacity. The results of theoretical studies of the process of heat transfer in the design and technological schemes of a three-pipe recirculator with counter-current and direct-current showed that the counter-current variant is more effective. Optimization of the results of theoretical studies allowed us to determine the dependence of the design parameters of the three-pipe heat exchanger on the volumetric flow rate of air, subject to the highest useful thermal power.

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