Discrete event heat transfer simulation of a room

Abstract

The paper presents a new proposal of a discrete event simulation (DEVS) model for heat transfer in an enclosure. To our knowledge this is the first proposal in this direction, therefore the model is not comprehensive (has no windows, no ground coupling,etcetera). It is a first step of DEVS into the heat transfer in buildings. The model presented is just one possible implementation for a single thermal zone, although it has been designed to be used in multi-zone models. Common methods like CTF (conduction transfer functions) or RTF (response transfer functions) cannot be used. Instead it employs the successive transition state formulation for the 1D conduction heat transfer through multi-layered walls. An example test room has been calculated and the results compared with software that uses well known methods (CTF,RTF). Finally the DEVS model has been tested with a random convective internal-load signal.Keywords: Successive state transition method, Building energy simulation, Discrete event simulation, DevsNumber of boundary conduction elements of the i-zone, equal as well to the number of its boundary surfaces

Discrete event heat transfer simulation of a room using a Quantized State System of order two, QSS2 integrator

“…In paper [1] it was shown how to build a DEVS model for a room. In that model there was a component named twofold-local-surfacebalance which represents the 1D heat conductive element.…”

“…Additionally, the devs model of the room has a devs static type named RAD-lw (see Ref. [1]). This element calculates the infrared radiant heat flux exchange for a given new set of temperatures, obtained after calling all the conductive elements (surface-local-balance).…”

“…Other components (see Ref. [1]) are devised to achieve the global thermal balance for the zone/room or enclosure, iterating over the infrared radiation heat exchange. ; if x:port2fzone; q radÀsrc ; weatherg state)re À compute s)0 s)∞…”

“…In a previous paper [1] it was proposed a DEVS (Discrete Event Simulation) model for a single room. Although there are many well known and powerful software tools [3e5].…”

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a b s t r a c tIn a previous paper [1] it was shown a proposal for a discrete event simulation (DEVS) model of a thermal zone. A quantized state integrator of order one (QSS) was used to integrate the evolution of the room air temperature.

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