Civil Engineering Reference
In-Depth Information
these control variables at their reference values, through adjusting the energy
produced. Thus, the balance between production and consumption is achieved.
(6) Modeling and simulation of the system
s operation in dynamic mode
'
To this end, the system
is global mathematical model is built, on the basis of
the energy balances, where the main accumulations of energy existing in the
system are taken into consideration:
'
Accumulation of electric energy in the battery, by means of which the
electric power transfers are achieved,
Accumulation of thermal energy in the heat storage tank, by means of
which the heat is transferred from sources to consumers.
The dynamic components of this model are generated by:
(a) energy balance equations, at level of the two energy accumulators,
(b) models of the control subsystem components,
(c)
simpli
ed models of dynamics of the energy sources, which have their
own control system (like the Stirling engine or the boiler).
The purpose of this analysis is twofold:
to check if the nominal values of the component outputs (which have been
established in basic action 4 and have been considered satisfactory from
the point of view of the system
s operating in stationary mode) are satis-
factory in the dynamic mode also, and to adjust these values if not;
'
to elaborate the global functional model of the whole system, based on the
comparative evaluation of its global performances when a certain func-
tional model of the two energetic subsystems ensemble is applied (namely
the thermal subsystem and the electric subsystem), associated with a cer-
tain structural model of the control subsystem.
1.4 Design Process
In what follows, the design process for a mCCHP system will be divided into two
stages:
Structural design, which includes the
first seven steps of the design process and
is
finalized by a number of structural models for the mCCHP system, based on
which the shift to the system dynamics analysis is possible;
Functional design, which includes the next
five steps of the design process and
is
finalized by the documentation based on which the mCCHP system may be
actually manufactured.
Search WWH ::
Custom Search