In the recent
years, has increased the need to reduce fossil fuel consumption, mainly
responsible of air pollution and climate change.
The use of
alternative energy sources have started to affect all sectors, from industrial
to civil. Don’t forget that in this direction are moving all industrialized
countries (Kyoto protocol 16 February 2005).
energy sources are multiple and can reduce the human dependence on fossil fuel.
They are derived, directly or indirectly, from the sun.
inexhaustible source of energy, even if a random source, this problem is often
solved by technical (tank of thermal energy).
In this thesis is
considered the use of solar energy in the production of steam at a pressure of
6 bar and flow rate of 700 kg/h.
For the production
of steam related to the conditions indicated below, an analysis in the
technical/commercial scope prompted to choose the use of parabolic trough
concentrators, which are a system for the capture of solar energy. These
concentrators allow to lead heat transfer fluid to a high temperature, that is
flowing within the central manifold. The solution provides the presence of two
separate circuits: heat transfer fluid and water fluid. With the use of a tank
of thermal energy, you can solve the problem of the uncertainty of the solar
source, maintaining the steam at a constant temperature. The plant is completed
with a natural gas boiler with integrative function, which comes into operation
when the solar energy falls below the minimum threshold programmed.
The operation of
the plant was analysed by a simulation software, in order to properly size the
For the dynamic
simulation of the plant has been used the code TRNSYS, which stands for
"TRaNsient SYstem Simulation Program”, version 16. The code was developed by
"Solar Energy Laboratory” of the University of Wisconsin-Madison and currently
is one of the most reliable tools for dynamic simulation of energy systems.
Figure 2 shows the
energy supplied to the boiler for different sizes of the absorbing surface
throughout the year.
increases with the extension of the solar field, but with non-linear law. This
observation justifies the optimization of the plant, which makes maximum energy
savings in relation to the cost of implementation.
feature is the saving of natural gas, with consequent reduction of carbon
dioxide emitted into the atmosphere.
|ENERGY NEEDED [GJ]
|FUEL QUANTITY [m3]
|REDUCTION OF CO2EMISSIONS [kg]
|Fuel necessary to provide the correct amount of
energy to the heat transfer fluid and saving of CO2 emitted into the
Degree thesis, academic year 2013/2014
Department of Industrial Engineering
Supervisor: Prof. GIORGIO PAGLIARINI
Ing. CARLO CORRADI
Ing. RICCARDO GUERRA