Civil Engineering Reference
In-Depth Information
4 Opportunities for Further Works
Although significant works have been completed, there are still obvious oppor-
tunities to catch up to further develop this technology, which are outlined as
below.
4.1 Developing New Feasible, Economic
and Energy-Efficient System
The aforementioned system types were found their own disadvantages that have
prohibited wide application of these systems in practice. The opportunity to
develop new system types to replace the existing systems still remains open, and
very recently, a new method to remove PV heat and utilise this part of heat was
proposed (Zhao
2010
). In further study, the emulsified PCM slurry, as a latent heat
convertor/conveyor, will be brought into the PV/T system to remove the PV heat,
and this part of heat will be used to provide space heating, hot water supply and
ventilation of the buildings, by running a combined operation of the PV/T mod-
ules, a heat pump, a heat storage and a slurry-to-air heat exchanger. This will open
up a new way to develop a more feasible, economic and energy-efficient PV/T
system; however, the claimed advantages of the system will need further valida-
tion through in-depth theoretical and experimental studies. Apart from this, other
types of PV/T configurations are also open to exploration.
4.2 Optimising the Structural/Geometrical Parameters
of the Existing PV/T Configurations
Of the four existing PV/T system types, air- or water-based types are technically
and commercially very mature and have no obvious room to improve their per-
formance. The refrigerant-based type is still in the research stage and space still
remains to improve its performance through the optimal study of the structural/
geometrical parameters of this type of the PV/T module. The key issue is to find a
route to overcome the difficulties remaining in the existing refrigerant PV/T type,
i.e. potential refrigerant leakage, unbalance refrigerant distribution and challenges
in retaining pressurisation and depressurisation conditions at different parts of the
system. Heat-pipe-based system is also in the start-up stage and remains large space
to develop the optimised system configurations. The low-cost flexible loop heat
pipes with built-in capillary would be a good choice to replace the existing parallel
laid heat pipes and have potential to reduce the cost of the system and build up the
excellent heat transfer between PVs and secondary fluid (Zhang et al.
2013
).
This work is currently being undertaken by the authors as part-work of an indus-
trial-funded research project.
