Effect of Evaporator Position on Heat Pump Assisted Solid Desiccant Cooling Systems

Shuo Liu,Chang-Ho Jeong,Myoung-Souk Yeo

doi:10.3390/en13225918

Shuo Liu, Chang-Ho Jeong + Show 1 more

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https://doi.org/10.3390/en13225918

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Journal: Energies	Publication Date: Nov 13, 2020
Citations: 8	License type: CC BY 4.0

Affiliation: Seoul National University, University of Suwon

Abstract

The packaged terminal air conditioning with reheat (PTACR) system, as a commonly used dehumidification system, faces the problem of extra energy consumption in the deep-cooling and reheating processes. Therefore, different heat pump assisted hybrid solid desiccant cooling (HPDC) systems were proposed and their characteristics were investigated via EnergyPlus simulations. The system energy efficiency presents an upward trend with the increase in outdoor temperature and humidity. A high-humidity climate leads to the improvement of system performance. The dehumidification performance of the desiccant wheel in the HPDC system declines when outdoor humidity increases. Compared with the PTACR system, the energy consumption of the HPDC system in which the evaporator was placed upstream of the desiccant wheel is reduced by 36%, 66%, and 64%, respectively, under different high-humidity climates. The system maintained the indoor environment within the comfort zone, and eliminated the need for a heat source for desiccant regeneration. In conclusion, the HPDC system is an available alternative that considers both energy consumption and system performance. Placing the evaporator upstream of the desiccant wheel is more advantageous in high-temperature and high-humidity climates.

Highlights

In high-humidity climates, the indoor humidity of superinsulated residential buildings with significant air tightness tends to be high [1]
When packaged terminal air conditioning (PTAC) systems are used, humidity discomfort occurs owing to the inability of this system to control the indoor humidity [2]
A PTAC with reheat (PTACR) system can be employed as an alternative to a conventional PTAC system

Summary

Introduction

In high-humidity climates, the indoor humidity of superinsulated residential buildings with significant air tightness tends to be high [1]. When packaged terminal air conditioning (PTAC) systems are used, humidity discomfort occurs owing to the inability of this system to control the indoor humidity [2]. It is necessary to propose a system or system operation mode that can control the indoor temperature and humidity. The deep-cooling and reheating of the supply air in the former theoretically leads to excessive energy consumption. This system type is not suitable for the case of high latent load [3]. Current research efforts on Energies 2020, 13, 5918; doi:10.3390/en13225918 www.mdpi.com/journal/energies

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