Energy consumption and optimization of internally cooled/heated liquid desiccant air-conditioning system: A case study in Hong Kong

Ronghui Qi, Lin Lu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

45 Citations (Scopus)

Abstract

LDAC (liquid desiccant air-conditioning system) is promising for reducing the energy consumption, and improving the indoor air quality. In this paper, the operation performance of LDAC with internally cooled/heated dehumidifier/regenerator was simulated and optimized. The cooling tower and solar collectors were employed as the cooling/heating source. Four nested iteration loops were developed and solved for system modeling. A typical commercial building in Hong Kong was selected as a case study, which air-conditioning load was obtained by Energy-plus. Results show that with the increase of solar collector area, the electricity consumption of AC (air-conditioning systems) system reduced by 11-35% in original system, but only a part of dehumidification demand was handled with liquid desiccant ventilation, which led to a low chiller COP (coefficient of performance). By adding a cooling coil for the solution entering dehumidifier, the electricity saving effectively increased to 22-47%, while the heat demand for regeneration also increased by 17%. So, a heat exchanger between water leaving regenerator and solution leaving dehumidifier was introduced. With the lower thermal requirement (reduced by 20%) and higher solar fraction (increased from 30 to 40%), the saving further increased to 29-49%, and the required collector area obviously reduced by 50-60% for the similar energy saving purpose.
Original languageEnglish
Pages (from-to)801-808
Number of pages8
JournalEnergy
Volume73
DOIs
Publication statusPublished - 14 Aug 2014

Keywords

  • Energy consumption
  • Internally heated/cooled
  • Liquid desiccant air-conditioning system
  • Operation performance
  • Optimization
  • Simulation

ASJC Scopus subject areas

  • Pollution
  • Energy(all)

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