On the non-periodic unsteady heat transfer through walls

Antonopoulos, KA; Democritou, F

dc.contributor.author	Antonopoulos, KA	en
dc.contributor.author	Democritou, F	en
dc.date.accessioned	2014-03-01T01:09:29Z
dc.date.available	2014-03-01T01:09:29Z
dc.date.issued	1993	en
dc.identifier.issn	0363-907X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/11019
dc.subject	WALL HEAT TRANSFER	en
dc.subject	UNSTEADY	en
dc.subject	NONPERIODIC	en
dc.subject.classification	Energy & Fuels	en
dc.subject.classification	Nuclear Science & Technology	en
dc.subject.other	Air conditioning	en
dc.subject.other	Finite difference method	en
dc.subject.other	Mathematical models	en
dc.subject.other	Parameter estimation	en
dc.subject.other	Thermal conductivity	en
dc.subject.other	Thermal diffusion in solids	en
dc.subject.other	Thermal effects	en
dc.subject.other	Transients	en
dc.subject.other	Unsteady flow	en
dc.subject.other	Wall flow	en
dc.subject.other	Nonperiodic unsteady wall heat transfer	en
dc.subject.other	Heat conduction	en
dc.subject.other	Air Conditioning	en
dc.subject.other	Heat Flow	en
dc.subject.other	Heat Transfer	en
dc.subject.other	Transients	en
dc.title	On the non-periodic unsteady heat transfer through walls	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/er.4440170508	en
heal.identifier.secondary	http://dx.doi.org/10.1002/er.4440170508	en
heal.language	English	en
heal.publicationDate	1993	en
heal.abstract	Existing calculation methods of the transient heat flow through walls for air-conditioning applications, assume periodic outdoor conditions. Therefore, the effect of a temporary temperature rise on the indoor heat flow is usually neglected. In the present work an attempt is being made to model the related non-periodic transient problem. The method of approach is based on a finite-difference solution of the transient heat conduction equation within the wall. Outdoor air temperature deviation parameters are introduced, which characterize any temporary deviation of the outdoor air-temperature from periodicity. Indoor heat flow deviation characteristics are defined, which describe the deviation of the indoor heat flow from periodicity, provoked by the corresponding outdoor air temperature deviation. A parametric study is conducted, where the effects of the temperature deviation parameters on the indoor heat flow deviation characteristics are examined. It has been found that (a) the maximum heat flow deviation varies linearly with the mean temperature difference, (b) the restoration ratio is practically independent of the temperature amplitude difference, and (c) an increase in the wall thermal diffusivity results in a decrease of the maximum heat flow deviation. The practical importance of the present analysis is that it helps towards the estimation of peak loads under non-periodic outdoor conditions.	en
heal.publisher	JOHN WILEY & SONS LTD	en
heal.journalName	International Journal of Energy Research	en
dc.identifier.doi	10.1002/er.4440170508	en
dc.identifier.isi	ISI:A1993LY20200007	en
dc.identifier.volume	17	en
dc.identifier.issue	5	en
dc.identifier.spage	401	en
dc.identifier.epage	412	en