Influence of Covering Layer on Surface Temperature of Floor Radiant Heating System

2012 ◽  
Vol 204-208 ◽  
pp. 4260-4263 ◽  
Author(s):  
Hai Qian Zhao ◽  
Zhong Hua Wang ◽  
Lan Shuang Zhang
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Heating System ◽  
Radiant Heating ◽  
Wooden Floor ◽  
Surface Temperature Distribution ◽  
Covering Layer ◽  
Floor Surface ◽  
Space Saving ◽  
Cover Material

Floor radiant heating system has many advantages, energy and space saving, for example. The radiant floor is the radiator of floor radiant heating system, and its thermal parameters influence surface temperature distribution and comfort. In this paper, mathematical model of heat exchange coil under floor was established, and boundary heat transfer conditions were given. Based on these, surface temperature of different covering layer was calculated. According to the results, using different covering layer, the floor surface temperature has a great difference. Using wooden floor as cover material, the floor surface temperature is more moderate and uniform.

scholarly journals Acceptable surface temperature of floor radiant heating system based on thermal comfort study in southern China

2019 ◽  
Vol 80 ◽  
pp. 03007
Author(s):  
Xingyu Lu ◽  
Hong Liu ◽  
Yuxin Wu
Keyword(s):  
Surface Temperature ◽  
Thermal Comfort ◽  
Thermal Sensation ◽  
Southern China ◽  
Heat Exposure ◽  
Cumulative Effect ◽  
Heating System ◽  
Radiant Heating ◽  
Floor Surface ◽  
Floor Temperature

In winter, people's demand for heating is stronger and stronger in southern China, and the floor radiant heating system is more and more popular. However, there are no suitable guidelines or standards for the floor temperature of the heating system in this area. The insulation performance of buildings in southern is not as good as other area which have central heating system. So the acceptable floor temperature suitable for this area needed to be studied.12 healthy college students participated as samples in this experiment. The floor surface temperature was controlled by varying the temperature of water flowing underneath the floor. The main conclusions were as follows: 1) the floor surface temperature directly affected the skin temperature of the foot and the thermal comfort of the foot. There was a significant statistical relationship between the floor surface temperature and the overall thermal sensation. 2) The acceptable floor temperature ranged from 26.1 °C to 34.3 °C for sitting positions and 24.6 °C ~34.7 °C for standing positions. 3) Considering the head thermal comfort and the health effects of the cumulative effect of long-term heat exposure, the recommended upper limit of the floor temperature in this experiment is 31°C.

scholarly journals Surface Temperature Distribution Characteristics of Marangoni Condensation for Ethanol–Water Mixture Vapor Based on Thermal Infrared Images

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6057
Author(s):  
Guilong Zhang ◽  
Ziqiang Ma ◽  
Heng Li ◽  
Jinshi Wang
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Thermal Infrared ◽  
Water Mixture ◽  
Distribution Characteristics ◽  
Infrared Images ◽  
Single Droplet ◽  
Surface Temperature Distribution ◽  
Thermal Infrared Images

Marangoni condensation is formed due to the surface tension gradient caused by the local temperature or concentration gradient on the condensate surface; thus, the investigation of the surface temperature distribution characteristics is crucial to reveal the condensation mechanism and heat transfer characteristics. Few studies have been conducted on the temperature distribution of the condensate surface. In this study, thermal infrared images were used to measure the temperature distributions of the condensate surface during Marangoni condensation for ethanol–water mixture vapor. The results showed that the surface temperature distribution of the single droplet was uneven, and a large temperature gradient, approximately 15.6 °C/mm, existed at the edge of the condensate droplets. The maximum temperature difference on the droplet surface reached up to 8 °C. During the condensation process, the average surface temperature of a single droplet firstly increased rapidly and then slowly until it approached a certain temperature, whereas that of the condensate surface increased rapidly at the beginning and then changed periodically in a cosine-like curve. The present results will be used to obtain local heat flux and heat transfer coefficients on the condensing surface, and to further establish the relationship between heat transfer and temperature distribution characteristics.

scholarly journals Mock-up Test of Time Lag in Floor Heating Systems with PCM

2019 ◽  
Vol 111 ◽  
pp. 06061
Author(s):  
Sung Ho Choi ◽  
Tae Won Kim ◽  
Jin Chul Park
Keyword(s):  
Surface Temperature ◽  
Time Lag ◽  
Heating System ◽  
Time Lags ◽  
Heating Systems ◽  
Floor Surface ◽  
Time Required ◽  
Floor System ◽  
Change Material ◽  
Floor Heating

This research analyzes the time lag, which is a thermal storage performance parameter, when a phase change material is applied to the floor heating system of a mock-up laboratory. The following results are obtained. In terms of the time required for the floor surface temperature to reach 30 °C, the time lag of Room 2 (i.e., the room with the PCM-based floor system) was observed to be 15 min. Additionally, in terms of the time required for the floor surface temperature to decrease to 22 °C, Room 2 exhibited a time lag of 5 h 2 min. Therefore, the study concluded that longer time lags are observed with floor heating systems with PCM.

Shroud Heat Transfer Measurements From a Rotating Cavity With an Axial Throughflow of Air

1994 ◽  
Vol 116 (3) ◽  
pp. 525-534 ◽  
Author(s):  
C. A. Long ◽  
P. G. Tucker
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Vortex Breakdown ◽  
Rossby Number ◽  
Temperature Level ◽  
Centripetal Acceleration ◽  
Surface Temperature Distribution ◽  
Nusselt Numbers ◽  
Rotating Cavity

The paper discusses measurements of heat transfer obtained from the inside surface of the peripheral shroud. The experiments were carried out on a rotating cavity, comprising two 0.985-m-dia disks, separated by an axial gap of 0.065 m and bounded at the circumference by a carbon fiber shroud. Tests were conducted with a heated shroud and either unheated or heated disks. When heated, the disks had the same temperature level and surface temperature distribution. Two different temperature distributions were tested; the surface temperature either increased, or decreased with radius. The effects of disk, shroud, and air temperature levels were also studied. Tests were carried out for the range of axial throughflow rates and speeds: 0.0025 ≤ m ≤ 0.2 kg/s and 12.5 ≤Ω≤ 125 rad/s, respectively. Measurements were also made of the temperature of the air inside the cavity. The shroud Nusselt numbers are found to depend on a Grashof number, which is defined using the centripetal acceleration. Providing the correct reference temperature is used, the measured Nusselt numbers also show similarity to those predicted by an established correlation for a horizontal plate in air. The heat transfer from the shroud is only weakly affected by the disk surface temperature distribution and temperature level. The heat transfer from the shroud appears to be affected by the Rossby number. A significant enhancement to the rotationally induced free convection occurs in the regions 2≤Ro≤4 and Ro≥20. The first of these corresponds to a region where vortex breakdown has been observed. In the second region, the Rossby number may be sufficiently large for the central throughflow to affect the shroud heat transfer directly. Heating the shroud does not appear to affect the heat transfer from the disks significantly.

Use of Analytical Expressions of Convection in Conjugated Heat Transfer Problems

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
R. Karvinen
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Flow Direction ◽  
Superposition Principle ◽  
Industrial Applications ◽  
Transfer Coefficients ◽  
Flat Plates ◽  
Surface Temperature Distribution ◽  
Analytical Expressions

The heat transfer coefficient of convection from the wall to the flow depends on flow type, on surface temperature distribution in a stream-wise direction, and in transient cases also on time. In so-called conjugated problems, the surface temperature distribution of the wall and flow are coupled together. Thus, the simultaneous solution of convection between the flow and wall, and conduction in the wall are required because heat transfer coefficients are not known. For external and internal flows, very accurate approximate analytical expressions have been derived for heat transfer in different kinds of boundary conditions which change in flow direction. Due to the linearity of the energy equation, the superposition principle can be adopted to couple with these expressions the surface temperature and heat flux distributions in conjugated problems. In the paper, this type of approach is adopted and applied to a number of industrial applications ranging from flat plates of electroluminecence displays to the optimization of heat transfer in fins, fin arrays and mobile phones.

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