Transient three-dimensional numerical solution of night ceiling cooling using PCM-embedded piping

Tzivanidis, C; Antonopoulos, KA; Kravvaritis, ED

dc.contributor.author	Tzivanidis, C	en
dc.contributor.author	Antonopoulos, KA	en
dc.contributor.author	Kravvaritis, ED	en
dc.date.accessioned	2014-03-01T02:04:17Z
dc.date.available	2014-03-01T02:04:17Z
dc.date.issued	2011	en
dc.identifier.issn	07339402	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/29417
dc.subject	Ceiling cooling	en
dc.subject	Night cooling	en
dc.subject	Phase change materials	en
dc.subject	Space cooling	en
dc.subject.other	Cold waters	en
dc.subject.other	Daily peak load	en
dc.subject.other	Electricity prices	en
dc.subject.other	Electricity-consumption	en
dc.subject.other	Numerical procedures	en
dc.subject.other	Numerical solution	en
dc.subject.other	Phase change process	en
dc.subject.other	Related functions	en
dc.subject.other	Storage capacity	en
dc.subject.other	Triangular functions	en
dc.subject.other	Ceilings	en
dc.subject.other	Concrete slabs	en
dc.subject.other	Cooling	en
dc.subject.other	Embedded systems	en
dc.subject.other	Phase change materials	en
dc.subject.other	Thermoelectric equipment	en
dc.subject.other	Three dimensional	en
dc.subject.other	Cooling systems	en
dc.title	Transient three-dimensional numerical solution of night ceiling cooling using PCM-embedded piping	en
heal.type	journalArticle	en
heal.identifier.primary	10.1061/(ASCE)EY.1943-7897.0000048	en
heal.identifier.secondary	http://dx.doi.org/10.1061/(ASCE)EY.1943-7897.0000048	en
heal.publicationDate	2011	en
heal.abstract	A numerical procedure is developed for solving transient, three-dimensional heat-transfer problems of space cooling by using cold water flowing during the night within regularly arranged pipes, embedded in the ceiling within a layer of phase change material (PCM). Such systems are advantageous over the usual ceiling cooling systems because (1)the PCM layer may store considerably greater amounts of heat than those stored in the concrete slab, and (2)night cooling takes place under reduced electricity prices and meets the requirement of smoothing out electricity consumption by reducing daily peak loads. To simulate the phase change process, the concept of effective thermal capacity function is used, which is determined experimentally and then generalized by using triangular functions. Tests are also made with related functions given in the literature. The predictions of this study showed that the use of night ceiling cooling systems with PCM-embedded piping may offer energy savings and more thermal comfort than systems without PCM, even in cases in which system parameters do not permit the user to take advantage of the entire PCM storage capacity. The developed numerical procedure may be used for defining, in each case, the proper values of the system parameters to completely take advantage of the PCM storage capacity. © 2011 American Society of Civil Engineers.	en
heal.journalName	Journal of Energy Engineering	en
dc.identifier.doi	10.1061/(ASCE)EY.1943-7897.0000048	en
dc.identifier.volume	137	en
dc.identifier.issue	4	en
dc.identifier.spage	177	en
dc.identifier.epage	186	en