Investigation of Thermal Sensation of Occupants in Domestic Buildings Located in Different Regions of China
Zhen Peng,
Wu Deng,
Yuanda Hong
Issue:
Volume 8, Issue 3, September 2019
Pages:
45-55
Received:
8 June 2019
Accepted:
15 July 2019
Published:
30 July 2019
Abstract: Thermal comfort sensation is different among people. Different climatic areas, such as the tropics and cold regions, may require different thermal parameters. This study analyses the thermal sensation of occupants in domestic buildings in three regions of China (Jinan, Xining, and Guangzhou). Filed measurements were conducted in selected domestic buildings located in Jinan, Xining and Guangzhou. The studied parameters include ambient air temperature, indoor air temperature, indoor radiation temperature, airflow velocity, predicted mean vote (PMV) and actual mean vote (AMV). In addition, a survey to investigate the actual comfort levels of occupants was completed by the occupants. The main aim is to identify the differences in thermal sensation of occupants living in different regions and in different types of buildings. Moreover, this study further analyses the effects of the ambient environment on indoor thermal comfort. The correlation between the actual thermal sensation and the predicted thermal sensation is discussed. Results show that the ambient environment has a greater effect on the thermal comfort level of naturally ventilated houses than those ventilated by air conditioners. Moreover, Fanger’s predicted mean vote (PMV) model is good at predicting the thermal sensation of occupants living in air-conditioned houses; however, the model is not a good predictor for occupants living in naturally ventilated houses. Occupants in naturally ventilated houses have a wider range of thermal acceptance than those living in air-conditioned houses.
Abstract: Thermal comfort sensation is different among people. Different climatic areas, such as the tropics and cold regions, may require different thermal parameters. This study analyses the thermal sensation of occupants in domestic buildings in three regions of China (Jinan, Xining, and Guangzhou). Filed measurements were conducted in selected domestic b...
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Consideration of Double Discrete Inclined Ribs in Low Curvature Coil for GSHP System
Teguh Hady Ariwibowo,
Akio Miyara,
Keishi Kariya
Issue:
Volume 8, Issue 3, September 2019
Pages:
56-64
Received:
8 July 2019
Accepted:
6 August 2019
Published:
19 August 2019
Abstract: This article presents an investigation of a low curvature coiled tube with double discrete inclined ribs for an application to ground heat exchanger used in ground heat pump systems. Computational fluid dynamics is employed to analyze the heat transfer and fluid flow with several ribs. The analysis performs detailed study involving flow behavior, pressure drop, heat transfer rate, wall heat flux, absolute vorticity flux for a range of ribs height (0.45 mm, 0.75 mm, and 1 mm) and flowrate (ranging from 6 L/min to 10 L/min) on curvature of coil 2.22 m-1. COP improvement factor, which is a function of heat transfer enhancement and pressure loss increase, is evaluated. The increasing of ribs height can deviate secondary flow, which contributes to heat transfer and pressure drop enhancement. In the case of higher ribs, circumferential heat flux distribution tends to be more fluctuated. The heat flux distribution also becomes smaller with the increasing of axial distance. The COP improvement factor significantly improves with the increase of ribs height. On the other hand, the COP Improvement factor tends to decrease with the increase in flow rate. The application of ribs in a low curvature coil is attractive and has the potential for Slinky-coil ground heat exchangers.
Abstract: This article presents an investigation of a low curvature coiled tube with double discrete inclined ribs for an application to ground heat exchanger used in ground heat pump systems. Computational fluid dynamics is employed to analyze the heat transfer and fluid flow with several ribs. The analysis performs detailed study involving flow behavior, p...
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