Representation of a Thermosiphon System Via
Neural Networks Considering Installation Parameters
1 2 1 1 ~22
L. E. Zairatel, E. M. Pereira , L. A. R. Oliveira', V. P. Gill, T. R. A. Santos', B. M. Nogueiral, M. A. Rodrigues
UNA University; 2 Energy Researches Group (GREEN)
Brasil.
Abstract- The research of alternative forms of energy
production became more important in a context where the
natural resources are scarce. In this sense, thermosiphon
systems have been developed as an alternative way of energy
economy for the water heating process using a renewable energy Cool water tank
source: the sun. A thermosiphon system is greatly influenced by
several parameters: the ambient temperature (Tamb), the input
OLtPLt
water temperature (Tin), the solar irradiance (G), the flow rate
warm
(in), the inclination of the solar collector (I), the height of the Storage tank water
water storage tank (H) and mainly by the manufacturing process. Inp
Nowadays, there are interests in the development of analytical water Solar collector
models that consider parameters of installation such as: height of
the water storage tank and inclination of the solar collector.
These analytical models can be complex and non-linear. In the
last decades, ANN (i.e. Artificial Neural Networks) have been
used to represent many kinds of industrial processes, dealing
F
_
with the complexity and non-linearity of them. Moreover, ANN Fig. 1. Schematic diagram of thermosiphon system.
are capable to deal with manufacturing aspects unconsidered by
the analytical models but that are important to determine the The performance of a thermosiphon system has been
efficiency of the real thermosiphon system. In this work, ANN investigated, both
experimentally
and
analytically, by
have been proposed as a new alternative to represent numerous researches [1-8]. The efficiency of this kind of
thermosiphon system considering the different parameters systems can be calculated through the equation:
related to the efficiency. A trained ANN can eliminate the
necessity of new laboratory experiments for real and new
mc
(T -T
T
conditions of installation. p out in1
Keywords- Artificial Neural Networks, Thermosiphon System, GA ( )
Solar Energy. extern
I. INTRODUCTION where:
ri
is the thermal efficiency, mh is the flow rate,
cp
is the
water heat capacity, Tout is the water output temperature, Tin is
Due to the hydrographic basins decreasing situation around
the water input temperature, G is the solar irradiance and
the world, associated with the constant population increasing,
Aextern is the area of the collector.
a new reality can be noticed where the traditional way of
In the last years, ANN have been proposed as a powerful
energy producing (by hydroelectric power plants) may not be
computational tool. ANN have several advantages compared
sufficient. Therefore, new ways of energy producing are
to other techniques such as: their good performance when
necessary and, among these, solar energy systems are an dealing with non-linear problems, their generalizing capacity
alternative. and the short processing time that can be reached when trained
Solar energy systems, specifically solar water heaters, have nets are in operation. The performance of this kind of systems
considerable importance as substitutes of traditional electrical
depends of its components, geometrical characteristics,
systems. An example of water heating system is called manufacture process and installation conditions involving the
thermosiphon, the most widely used of all solar energy
solar collector inclination and the water storage tank height.
thermal convention devices. Thermosiphon systems have In references [4,5] the representation of thermosiphon
competitive cost compared to the conventional energy systems systems through ANN (i.e. Artificial Neural Networks) is
available
Intthe
whole world. discussed, although installation parameters were not
Fig. 1 contains a schematic diagram of a thermosiphon considered. The main objective of this work is to represent
system, where the most important component is the collector the thermosiphon system considering installation parameters.
plate or solar collector. In this work is proposed a neural representation for the
thermosiphon system considering the installation parameters.
This representation permits to consider manufacture aspects,
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