1,721,045 research outputs found
Analysis of the application of an open cycle absorption heat pump in industrial convection drying
No full textAnalysis of an air conditioning system using underground thermal energy storage combined with chemical dehumification
No full textIn the present paper the analysis of the performance of an underground thermal energy storage (UTES) system is compared to a traditional HVAC plant. In particular the study is aimed at evaluating the opportunities offered by the combination of the UTES with a desiccant based air handling unit (AHU). Differently from the conventional solutions, the humidity control is here separately obtained by chemical dehumidification of the ventilation airstream performed by liquid desiccants in a packed column. In winter the AHU configuration allows sensible and latent heat recovery while in summer the borehole heat exchangers water temperature is generally suitable to meet the sensible load without any integration by the chillers. In this way not only operation but above all the investment costs are reduced and the UTES system competitiveness is increased. The described solutions are investigated by a computer simulation referring to a modern office building in a climate of the northern Ital
Sistemi di climatizzazione a pavimento radiante alimentati da pompa di calore geotermica: valutazioni energetiche ed economiche
No full textExperimental report on the reliability of ammonia - water absorption chillers
No full textThe analysis of a large amount of data on the failures of absorbtion refrigeration machines of the ammonia-water typr was carried out. The data derive from the records of a 10 years maintenance contract under which every machine was installed. The records were comuterized for the period 1989 - 1992, and they refer to sales starting from 1980 (i.e. to 73 778 machines). The failures are classified, identifying the most serious (generator and solution pump). The rate of early failures is rather high, but the failures are generally minor and easily repaired. The production quality was not constant, with a very bad year in 1984. The failure rate is evaluated for the first 10 years of life of the equipment. In general terms, one machine in two does not require any intervention during that period
Development of innovative plate heat exchangers for refrigeration applications
No full textThis paper presents the experimental work carried out to apply the enhanced surfaces widely used for intube refrigerant condensation and vaporisation, such as micro-fin and cross-grooved, into plate heat exchangers (PHE). The paper investigates also the effect of an increase in the surface roughness of the plate on the heat transfer performance in refrigerant vaporisation. The enhanced surfaces are experimentally evaluated both in vaporisation and condensation tests and compared against a traditional PHE surface. The experimental facility and the test procedures are fully described. The experimental results show that the increase in surface roughness is useful only in vaporisation, whereas the cross-grooved surface is useful both in vaporisation and condensation. The cross-grooved surface gives an increase in the heat transfer performance from 40% in vaporisation to 50% in condensation with respect to a traditional PHE surfac
sj-pdf-1-lrt-10.1177_14771535211046521 – Supplemental Material for Lighting conditions in physiotherapy centres: A comparative field study
No full textSupplemental Material, sj-pdf-1-lrt-10.1177_14771535211046521 for Lighting conditions in physiotherapy centres: A comparative field study by L Zaniboni, M Sarey Khanie, G Pernigotto, J Toftum, A Gasparella and BW Olesen in Lighting Research & Technology</p
Analisi termica dei giunti tra serramento e muratura: incidenza sulla prestazione energetica degli edifici ed efficacia delle principali soluzioni correttive
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