1. Novel window thermoelectric module integration systems for building applications
- Author
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Xu, Qi
- Subjects
TH6014 Environmental and sanitary engineering of buildings - Abstract
The work covered in this thesis is an investigation of novel thermoelectric (TE) heat pump systems coupled with energy-efficient technologies (heat recovery ventilation and evaporative cooling) for small single room applications. In the first part of the thesis, a window thermoelectric based heat pipe heat recovery ventilator (WTEHPV) unit for heating purpose was designed and evaluated by experimental investigation and theoretical modelling. Both the experimental investigations on the prototypes without and with air filter assembled were carried out within an environmental control chamber under laboratory condition. The results showed that with the working current for thermoelectric modules increasing, the heating generation rate will increase, while the Coefficient of Performance for heating purposes (COPh) shows a decreased trend. During the whole testing, the maximum temperature rise of 7.9 °C and the maximum heating capacity of 172W were obtained for the WTEHPV system at the operating current of 3A for TE modules. The COPh of the prototype ranged from 1.71 to 1.34 with operating current ranged from 1A to 3A. By comparison of the experimental results and modelling results, the modelling showed an acceptable agreement with the testing, that could be developed for further performance evaluations. In another case, a window thermoelectric based plate fin heat recovery ventilator (WTEPFV) unit for heating application was explored with a parallel flow arrangement. The prototype design, a mathematical analytical model and a corresponding laboratory testing are introduced, to explore the effects of various parameters on the performance including working current, thermal resistance of heat sinks and operating environment (i.e. temperature difference between indoors and outdoors). The heating capacity of the WTEPFV unit ranged from 70W to 152W and the COPh ranged from 2.12 to 1.61. These were obtained with 1A to 2A current supplied to the TE modules in the laboratory investigation. According to the modelling, both the heating capacity and COPh value of each TE module would decrease gradually with the growing number of TE modules (n). Also, better heating performance could be achieved with larger working current input/ lower thermal resistance of heat sinks and larger temperature gap between the interior and ambient environment. With the issue of conventional vapour compression systems, the third prototype of a modular window/wall thermoelectric heat pump assisted with evaporative cooling (WTE-EC) unit was proposed for small space cooling. From the experiment conducted under laboratory conditions, it was found that as the working current for TE modules is elevated, the cooling capacity of WTE-EC system would increase, while the cooling Coefficient of Performance, COPc values would decrease. With 1A to 3.5A working current for TE modules, the cooling capacity ranged from 38W to 70W and the COPc of the system ranged from 1.79 to 0.36. A suitable heat sink for hot side heat dissipation is essential for the TE module to function as expected. This prototype is designed to work with other TE based integration cooling devices for a single room application due to its small cooling capacity. This research finally analysed the annual operational performance, economic and environmental impacts of the TE module integrated heat recovery ventilation prototypes through simulation. Overall, the developed window-installed TE modules coupled with energy-efficient technologies could be a promising technology to contribute to low carbon goals.
- Published
- 2021