Description:
<jats:p>This article presents the developed methodology for the numerical simulation
of radiation heat transfer from water panel heaters and optimization results
of water temperature in the supply pipeline from the mass flow rate of the
heat-carrier and the surface area for a given thermal power of the panel
system. A numerical mathematical model is developed in the assumption that
heat transfer occurs by means of radiation heat exchange by longitudinal
ribs and pipes, which are thermally insulated on top. It is assumed that the
temperature of the rib base is equal to the temperature of the outer wall of
the pipe. The irregularity of the radiation density in different directions
depends on the angle and distance to the irradiated area. The aim of the
work is to develop a methodology to simulate the heat transfer processes of
a radiation panel water heating system and optimization of design and
operating parameters. The radiation intensity is determined by a numerical
method using the MATLsoftware package. Our results of experimental
studies of the radiation flux density are presented and compared with the
results of numerical ones. The thermodynamic efficiency of a panel heating
system is analyzed using the entropy production method (exergy destruction).
The multicriteria optimization of water temperature in the supply pipeline
is performed by LP?-search. It is found that the unevenness of surface
temperature of panels reaches 24.4% as well as for the panels of about 50m
in length a decrease in water temperature to 20K is observed, which leads to
the unevenness of radiation flux density over the heated area. The area of
the cooling system as a function of water temperature and the conditions
under which the entropy production in the system is minimal is determined.</jats:p>