Investigation of a Ground Coupled Photovoltaic Thermal Desiccant Cooling and Heating (GPVTDCH) System

摘要

This study investigates the performance of a novel solar desiccant cooling and heating cycle, that uses ground water as the cooling source and photovoltaic thermal (PV/T) collectors as the heating source, to provide annual space air conditioning (fresh air ventilation, dehumidification, cooling and heating) for an office building in a humid subtropical climate of Sydney, Australia. In the dehumidification and cooling mode, the hot and humid outdoor air is pre-cooled. dehumidified and cooled by the ground coupled PV/T desiccant cooling and heating (GPVTDCH) system before it is supplied to indoor. This process enables the desiccants to be regenerated by a low grade heat source (temperatures less than 60°C). In the heating mode, the cold outdoor air is pre-heated by the heat exchanger, and then been further heated by the flat plate PV/T collectors before passing directly to indoor. To analyse the performance of the GPVTDCH system, a simulation model of the system and the office building was developed in TRNSYS. In addition, the energy consumption of fans and pumps were also sized and included in the TRNSYS model. This is an improvement to the previous work presented by the authors (Guo et al. 2014). Therefore, the performance of the GPVTDCH system can be better estimated for air ventilation, dehumidification. cooling and heating for an office building The GPVTDCH system annual system coefficient of performance (COP) and the reduction in the required heating and cooling energy consumption (sensible and latent) of the office building was evaluated for maintaining the indoor air conditions within the 20-26°C and 4-12 g kg~(-1) specific humidity for 95% of the operating time in a year (Standards Australia 2016). The simulation results show that the GPVTDCH system can supply satisfied air conditions with a peak annual system cooling COP of 10.1 and system heating COP of 14.9, and up to 70% reduction in the required heating and cooling energy consumption for the building.