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Article
Publication date: 4 March 2016

Huiju Park, Soo-kyung Hwang, Joo-Young Lee, Jintu Fan and Youngjin Jeong

This paper investigated the impact of the distance of the heating unit from the body in a multi-layered winter clothing system on effective thermal insulation and heating

585

Abstract

Purpose

This paper investigated the impact of the distance of the heating unit from the body in a multi-layered winter clothing system on effective thermal insulation and heating efficiency.

Design/methodology/approach

To identify changes in the thermal insulation and heating efficiency of electrical heating in different layers inside a winter clothing ensemble, a series of thermal manikin tests was conducted. A multi-layered winter ensemble with and without activation of a heating unit was tested on the thermal manikin under two different ambient temperature conditions (10°C and -5°C).

Findings

Results show that the effective thermal insulation of test ensembles increased by 5-7% with the activation of the heating unit compared to that without the activation. The closer the heating unit to the body, the higher the effective thermal insulation was in both ambient temperature conditions. This trend was more significant at lower ambient temperature.

Research limitations/implications

The results of this study indicate that providing electric heating next to the skin is the most effective in increasing effective thermal insulation and decreasing body heat loss in both ambient temperature (-5°C and 10°C). This trend was more remarkable in colder environment at -5°C of ambient temperature as evidenced by sharp decrease in heating efficiency and effective thermal insulation with an increase in distance between the manikin skin and heating unit at -5°C of ambient temperature compared to at 10°C of ambient temperature.

Practical implications

Based on the results, it is expected that proximity heating next to the skin, in cold environment, may reduce the weight and size of the battery for the heating unit because of the higher efficiency of electric heating and the potentially immediate perception of warmth supported by the greatest increase in effective thermal insulation, as well as the lowest heat loss that comes with activation of heating on the first layer in cold environment.

Originality/value

The finding of this study provides guidelines to sportswear designers, textile scientists, sports enthusiasts, and civilians who consider electric heating benefits for improved thermal comfort and safety in cold environments, especially in the areas of outdoor and winter sports and in military service. The results of this study indicate that providing electric heating next to the skin is the most effective in increasing effective thermal insulation and decreasing body heat loss in both ambient temperature (-5°C and 10°C).

Details

International Journal of Clothing Science and Technology, vol. 28 no. 2
Type: Research Article
ISSN: 0955-6222

Article
Publication date: 20 April 2015

Huy-Tien Bui and Sheng-Jye Hwang

The purpose of this paper is to develop a barrel heating system using induction heating instead of resistance heating. And, a working coil for the induction heating system…

Abstract

Purpose

The purpose of this paper is to develop a barrel heating system using induction heating instead of resistance heating. And, a working coil for the induction heating system was designed so that the barrel has uniform temperature distribution.

Design/methodology/approach

A coupling design combining the pitch of turns of working coil with the magnetic flux concentrators in the barrel induction heating system was developed to achieve uniform temperature distribution which was approximately the same as temperature uniformity obtained from that of resistance heating system.

Findings

In contrast to resistance heating method, induction heating is more efficient because the heating is directly applied on the work-piece. Its heating rate is higher than that of resistance heating method. However, the uneven temperature distribution in the barrel is the main disadvantage of the induction heating system. But, with proper design of adjusting the pitch of turns at the center of working coil and adding magnetic flux concentrators at areas with lower magnetic flux, the barrel heating system via induction can achieve temperature distribution uniformity.

Originality/value

Under proper design of working coil, the barrel heating system by induction method can achieve the same uniform temperature distribution as the barrel heated by resistance method, and could be practically used in an injection molding machine.

Details

Rapid Prototyping Journal, vol. 21 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 June 1999

James Douglas

Summarises the evolution of underfloor heating in buildings. Examines the main types of underfloor heating systems in ground floors. Discusses the pros and cons of this…

1182

Abstract

Summarises the evolution of underfloor heating in buildings. Examines the main types of underfloor heating systems in ground floors. Discusses the pros and cons of this method of heating buildings. Shows that with the introduction of flow‐applied screeds and plastic piping, as well as improved installation and control procedures, underfloor heating is making a comeback in a growing number of new‐build schemes in the UK. However, this study indicates that it will be many years before universal confidence in the system is achieved.

Details

Structural Survey, vol. 17 no. 2
Type: Research Article
ISSN: 0263-080X

Keywords

Article
Publication date: 27 February 2009

Ozan Kayacan and Ender Yazgan Bulgun

The purpose of this paper is to investigate the concept of “electrically conductive fabrics”. The primer applications that import electrical conductivity properties to…

1057

Abstract

Purpose

The purpose of this paper is to investigate the concept of “electrically conductive fabrics”. The primer applications that import electrical conductivity properties to textiles and clothing are summarized. Also the heated fabric panels produced by steel yarns are evaluated. Single and multi‐ply steel fabrics are applied to electrical current and their heating behaviors are observed and compared.

Design/methodology/approach

The integration of electronic components with textiles to create very smart structures is getting more and more attention in recent years. Most of the textile materials are electrical insulators. Hence, various types of fibers and fabrics having reasonably good electrical conductivity are required especially for electronically functional apparel products. The textile‐based materials being flexible and easily workable are the most preferred one in such cases. In this study, the steel yarns are placed in the fabric construction owing to their flexible characteristics. The heating panels used in this study are produced by conventional textile processes and applied to electrical current. For this purpose, an electronic circuit that contains textile‐based warming panels connected to a power supply, has been developed.

Findings

The heated steel fabric panels with different number of plies provide different heating degree intervals owing to the different resistance levels, Therefore, in the applications of textile‐based heating elements it is suggested that the electrical characterization of conductive materials should be examined and the materials that have the most appropriate electrical resistance characteristic must be applied. Furthermore, in the circuits used for heating function, the current amount depends on the electrical features of heating structures. Consequently, the pads with different plies have various efficient heating in point of time. It is recommended that the appropriate heating pad dimensions, ply or conductive yarn amounts and sufficient power supply conditions should be evaluated and chosen according to the desired heating level.

Originality/value

Electrically conductive stainless steel yarns are processed to form a heating panel that can be used within an electronic circuit as a warming mechanism.

Details

International Journal of Clothing Science and Technology, vol. 21 no. 2/3
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 23 March 2012

Eshagh Yazdanshenas and Simon Furbo

Low flow bikini solar combisystems and high flow tank‐in‐tank solar combisystems have been studied theoretically. The aim of this paper is to study which of these two…

Abstract

Purpose

Low flow bikini solar combisystems and high flow tank‐in‐tank solar combisystems have been studied theoretically. The aim of this paper is to study which of these two solar combisystem designs is suitable for different houses. The thermal performance of solar combisystems based on the two different heat storage types is compared.

Design/methodology/approach

The thermal performance of Low flow bikini solar combisystems and high flow tank‐in‐tank solar combisystems is calculated with the simulation program TRNSYS. Two different TRNSYS models based on measurements were developed and used.

Findings

Based on the calculations it is concluded that low flow solar combisystems based on bikini tanks are promising for low energy buildings, while solar combisystems based on tank‐in‐tank stores are attractive for the houses with medium heating demand and old houses with high heating demand.

Originality/value

Many different Solar Combisystem designs have been commercialized over the years. In the IEA‐SHC Task 26, twenty one solar combisystems have been described and analyzed. Maybe the mantle tank approach also for solar combisystems can be used with advantage? This might be possible if the solar heating system is based on a so‐called bikini tank. Therefore, the new developed solar combisystems based on bikini tanks is compared to the tank‐in‐tank solar combisystems to elucidate which one is suitable for three different houses with low energy heating demand, medium and high heating demand.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 22 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 7 January 2020

Martin Schulze and Egbert Baake

This paper aims to deal with different induction and conduction heating approaches to realize a tailored heating of round billets for hot forming processes. In particular…

Abstract

Purpose

This paper aims to deal with different induction and conduction heating approaches to realize a tailored heating of round billets for hot forming processes. In particular, this work examines the limits in which tailor-made temperature profiles can be achieved in the billet. In this way, a flow stress distribution based on the temperature field in the material can be set in a targeted manner, which is decisive for forming processes.

Design/methodology/approach

For the heating of round billets by induction, the rotationally symmetric arrangement is used and a parameterized 2D finite element method model is created. The harmonic electromagnetic solution is coupled with the transient thermal solution. For heating by means of conduction, the same procedure is used only with the use of a 3D model.

Findings

First results have shown that both methods can achieve very good results for billets with small diameters (d < 30 mm). For larger diameters, an adapted control of the heating process is necessary to ensure through heating of the material. Further investigations are carried out.

Practical implications

Using tailored heating for forging billets, several forming steps can be achieved in one step. Among other things, higher energy efficiency and throughput rates can be achieved.

Originality/value

The peculiarity of the tailored heating approach is that, in contrast to inhomogeneous heating, where only partial areas are heated, the entire component is heated to the target.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 39 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 September 2022

Feng Zhou, Zixuan Wang and Yuxiang Zhao

The purpose of this paper is to study the pipe-type electromagnetic induction heating device under power frequency condition.

10

Abstract

Purpose

The purpose of this paper is to study the pipe-type electromagnetic induction heating device under power frequency condition.

Design/methodology/approach

To reduce eddy current loss and improve heating efficiency, the structure of a pipe-type power-frequency electromagnetic heating device was optimized. Based on the maximum load flow formula, a parallel excitation winding structure is designed, and the distribution of electromagnetic field under four different powers is analyzed by simulation. Four heating modes were proposed according to the structure of diversion ring, inner wall and outer wall. Two heating modes with better heating effect were obtained by comprehensively considering the factors such as magnetic field distribution, thermal power and energy consumption.

Findings

The double-wall structure of the pipe-type electromagnetic heating device can make the heat source distribution more uniform, and the use of power-frequency power supply can increase security, the installation of diversion ring can make the heating more sufficient and the heating efficiency of the two heating methods selected according to the structural performance is more than 90%.

Originality/value

In view of the medium or high frequency of pipe-type electromagnetic heating device, it is necessary to configure high power electronic frequency conversion drive system, and eddy current can only be produced on the tube wall, resulting in uneven distribution of heat sources. A pipe-type power-frequency electromagnetic heating device with double-wall structure was proposed.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 13 September 2022

Xue Chen, Zhaohua Zhang and Yutong Yang

The purpose of this paper is to explore the distribution of local thermal sensitivity of human body heating and the local preferred heating temperature, and the influence…

Abstract

Purpose

The purpose of this paper is to explore the distribution of local thermal sensitivity of human body heating and the local preferred heating temperature, and the influence of this sensitive division on thermal response when heating human body in cold environment.

Design/methodology/approach

Eight subjects were invited to use carbon fiber heating patches in an environment of 5 and RH 50%, and eight body parts were selected to explore the heating sensitivity. By measuring the skin temperature and evaluating the subjective thermal sensation and thermal comfort, the thermal sensitivity of local body segments and the influence of single-zone and double-zone heating on human thermal response were explored.

Findings

The sensitivity of local heating on overall thermal sensation (OTS) was foot > back > chest > abdomen > waist > elbow > hand > knee. Both single-zone and double-zone heating can improve the OTS, but double-zone heating can reach thermal neutrality and thermal comfort. In order to prevent the high temperature of heating patches from damaging human body, the local skin temperature should be monitored in the design of local heating clothing, and 39.6 should be taken as the upper limit of local skin temperature.

Originality/value

The results provide a theoretical basis for the selection of heating position in local electric heating clothing (EHC) and the design of intelligent temperature adjustment heating clothing, improve the performance of local EHC and reduce energy consumption.

Details

International Journal of Clothing Science and Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0955-6222

Keywords

Book part
Publication date: 22 December 2016

Neil Hewitt, Ye Huang, Mingjun Huang and Caterina Brandoni

Currently heating and cooling in buildings is responsible for over 30% of the primary energy consumption in the United Kingdom with a similar amount in China. We analyze…

Abstract

Purpose

Currently heating and cooling in buildings is responsible for over 30% of the primary energy consumption in the United Kingdom with a similar amount in China. We analyze heat pumps and district thermal energy network for efficient buildings. Their advantages are examined (i.e., flexibility in choosing heat sources, reduction of fuel consumption and increased environmental quality, enhanced community energy management, reduced costs for end users) together with their drawbacks, when they are intended as means for efficient building heating and cooling.

Methodology/approach

A literature review observed a range of operating conditions and challenges associated with the efficient operation of district heating and cooling networks, comparing primarily the UK’s and China’s experiences, but also acknowledging the areas of expertise of European, the United States, and Japan. It was noted that the efficiency of cooling networks is still in its infancy but heating networks could benefit from lower distribution temperatures to reduce thermal losses. Such temperatures are suitable for space heating methods provided by, for example, underfloor heating, enhanced area hydronic radiators, or fan-assisted hydronic radiators. However, to use existing higher temperature hydronic radiator systems (typically at a temperatures of >70°C) a modified heat pump was proposed, tested, and evaluated in an administrative building. The results appears to be very successful.

Findings

District heating is a proven energy-efficient mechanism for delivering space heating. They can also be adaptable for space cooling applications with either parallel heating and cooling circuits or in regions of well-defined seasons, on flow and return circuit with a defined change-over period from heating to cooling. Renewable energy sources can provide either heating or cooling through, for example, biomass boilers, photovoltaics, solar thermal, etc. However, for lower loss district heating systems, lower distribution temperatures are required. Advanced heat pumps can efficiently bridge the gap between lower temperature distribution systems and buildings with higher temperature hydronic heating systems

Originality/value

This chapter presents a case for district heating (and cooling). It demonstrates the benefits of reduced temperatures in district heating networks to reduce losses but also illustrates the need for temperature upgrading where building heating systems require higher temperatures. Thus, a novel heat pump was developed and successfully tested.

Details

China and Europe’s Partnership for a More Sustainable World
Type: Book
ISBN: 978-1-78635-331-3

Keywords

Article
Publication date: 6 December 2021

Soyoung Kim, Kyunghi Hong and Heeran Lee

This study aims to provide information on how to monitor the temperature setting of a heating device in order to implement a heating unit successfully in the smart…

Abstract

Purpose

This study aims to provide information on how to monitor the temperature setting of a heating device in order to implement a heating unit successfully in the smart clothing by observing voluntary heating behavior of wearers.

Design/methodology/approach

Subjects wearing base layers and additional clothing were asked to turn on and off the switch when wanted in the cold environmental chamber. Tolerable range of skin temperature (TST) depending on the location of body was obtained by observing the temperature at the time when the heating device was turned on and off during a rest–running–rest protocol.

Findings

The TST was 32.8–49.4 °C and decreased to 31.3–37.6 °C around abdomen and back waist, respectively. Changes in the wearers' voluntary control behavior were observed depending on the individual's level of cold-sensitivity and activity level of rest and running. TST was 35.8–49.4 °C (Rest 1: rest before exercise), 40.0–42.0 °C (Running) and 35.3–43.2 °C (Rest 2: rest after exercise) for cold-sensitive group, whereas it was 32.8–36.2 °C (Running) and 34.4–45.7 °C (Rest 2: rest after exercise) for cold-insensitive group.

Originality/value

In this study, results with detailed body locations and wearer's thermal sensitivity provide practical references for the implementation of a heating device to the comfortable multilayered smart clothing.

Details

International Journal of Clothing Science and Technology, vol. 33 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

1 – 10 of over 42000