A study on the heat dissipation and thermal environment of a novel heated bed

Abstract

This study proposes a novel heated bed that can heat the whole room in the daytime and heat the surroundings of the bed at night. The conditions of conversion between the daytime and nighttime are achieved by the opening and closing of the fan and vents. The simplified calculation method of heat dissipation of the bed was obtained via the flow and heat transfer process analysis in two heating modes. Numerical simulations of heat dissipation and indoor thermal environment under different conditions in the daytime and nighttime were performed using computational fluid dynamics (CFD) to master the indoor temperature distribution characteristics. The simulation results were compared with the experimental results and show good agreement. The results show that the maximum of heat dissipation can reach 1300 W in the daytime and the indoor thermal environment can meet the human thermal comfort requirement. At night, the bed can create a high-temperature circle around it, which can ensure the sleep thermal comfort of the human body at a cooler indoor thermal environment, whose temperature can be 5°C lower than normal conditions. The heated bed can achieve the time-sharing district heating of room and reduce the heating energy consumption significantly. This study can provide the design and selection basis for the heated bed.

Keywords

Heated bed numerical simulation indoor thermal environment thermal comfort experiment

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References

Chen

Zhuang

Chen

et al . (2007) Field survey on indoor thermal environment of rural residences with coupled Chinese Kang and passive solar collecting wall heating in Northeast China. Solar Energy 81(6): 781–790.

Feng

Wang

et al . (2016) Study on solar KANG heating system for cold areas. Procedia Engineering 146: 536–540.

Fontana

(2011) Thermal performance of radiant heating floors in furnished enclosed spaces. Applied Thermal Engineering 31(10): 1547–1555.

Jiang

et al . (2013) A study on thermal performance, thermal comfort in sleeping environment and solar energy contribution of solar Chinese Kang. Energy and Buildings 58(2): 66–75.

Gao

Yang

(2016) Field measurements, assessments and improvement of Kang: Case study in rural northwest China. Energy and Buildings 111: 497–506.

Lin

Deng

(2008) A study on the thermal comfort in sleeping environments in the subtropics—Measuring the total insulation values for the bedding systems commonly used in the subtropics. Building and Environment 43(5): 905–916.

Long

(2013) Fluid Mechanics. Beijing, China: China Architecture & Building Press.

(2008) Practical Design Handbook for Heating and Air Conditioning. Beijing, China: China Architecture & Building Press.

Mezrhab

Bouali

Amaoui

et al . (2006) Computation of combined natural-convection and radiation heat-transfer in a cavity having a square body at its center. Applied Energy 83(9): 1004–1023.

10.

Miyazawa

(1994) Seasonal changes of environment at bedtime and on arising. In Proceeding of the 18th symposium on human-environment system Tokyo, 24 December (in Japanese).

11.

Pan

Chan

Xia

et al . (2012) Performance evaluation of a novel bed-based task/ambient conditioning (TAC) system. Energy and Buildings 44(1): 54–62.

12.

Saravanan

Sivaraj

(2015) Combined natural convection and thermal radiation in a square cavity with a nonuniformly heated plate. Computers & Fluids 117: 125–138.

13.

Song

(2017) Research on differentiated thermal requirement of human body and thermal environment design parameters for sleep in winter. PhD Thesis, Xi’an University of Architecture and Technology (in Chinese).

14.

Song

Liu

Zhou

et al . (2015) Temperature field of bed climate and thermal comfort assessment based on local thermal sensations. Building and Environment 95: 381–390.

15.

Wang

Chen

Liu

et al . (2016) Heat transfer characteristics of a novel sleeping bed with an integrated hot water heating system. Applied Thermal Engineering 113: 79–86.

16.

Wang

Liu

Wang

et al . (2014) Numerical and experimental analysis of floor heat storage and release during an intermittent in-slab floor heating process. Applied Thermal Engineering 62(2): 398–406.

17.

Wang

Liu

et al . (2017) Experimental study on the thermal performance of an enhanced-convection overhead radiant floor heating system. Energy and Buildings 135: 233–243.

18.

Wei

Chow

et al . (2015) Experimental study of a combined system of solar Kang and solar air collector. Energy Conversion and Management 103: 752–761.

19.

Xia

Zhang

(2015) Experimental research on a double-layer radiant floor system with phase change material under heating mode. Applied Thermal Engineering 96: 600–606.

20.

Yang

Liu

et al . (2012) Experimental study on the effect of low temperature ambient heater on improving human comfort. Journal of Central South University 43(10): 393–398.

21.

Zhang

Cai

Wang

(2013) Experimental and numerical analysis of lightweight radiant floor heating system. Energy and Buildings 61(2): 260–266.

22.

Zhang

(2007) Heat Transfer. Beijing, China: China Architecture & Building Press.

23.

Zhao

Zhu

Wang

et al . (2016) Numerical simulation on the thermal performance of hydraulic floor heating system with phase change materials. Applied Thermal Engineering 93: 900–907.

24.

Zhu

(2010) Built Environment. Beijing, China: China Architecture & Building Press.

25.

Zhuang

Chen

et al . (2009) Chinese Kang as a domestic heating system in rural northern China—A review. Energy and Buildings 41(1): 111–119.