제로에너지 공동주택에서 바닥복사난방패널의 방열량 설계 기준 평가

임재한 한국건축친환경설비학회 2022 한국건축친환경설비학회 논문집 Vol.16 No.4

This study aims to analyze the thermal output and downward heat loasses according to the pipe pitch of the floor heating panels for the design of a radiant floor heating system in a zero-energy apartment to compare the design heating load in zero-energy apartment housing unit. The thermal output and downward heat losses were analyzed according to the pipe pitches, flooring and pipe materials by using the universial single power function method in ISO 11855-2. The results showed that the heating load could be removed even if the pipe pitch of the existing radiant floor heating system is changed to around 350 mm as the thermal insulation and airtightness in the zero-energy apartment building has been greatly improved. The thermal output in individual heating was about 30% higher than that of district heating. In addition, it was found that it was necessary to consider the thermal resistance of flooring materials for the design of the radiant floor heating panel because it would affect the thermal output through the room air. When the lowerest floor was exposed to the outside air, downward heat losses greatly increased, so it would be necessary to increase the outside thermal insulation thickness for the energy saving during heating operation.

Effect of the Heat-exposure on Peripheral Sudomotor Activity Including the Density of Active Sweat Glands and Single Sweat Gland Output

Jeong-Beom Lee,Tae-Wook Kim,Young-Oh Shin,Young-Ki Min,Hun-Mo Yang 대한생리학회-대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.5

Tropical inhabitants are able to tolerate heat through permanent residence in hot and often humid tropical climates. The goal of this study was to clarify the peripheral mechanisms involved in thermal sweating pre and post exposure (heat-acclimatization over 10 days) by studying the sweating responses to acetylcholine (ACh), a primary neurotransmitter of sudomotor activity, in healthy subjects (n=12). Ten percent ACh was administered on the inner forearm skin for iontophoresis. Quantitative sudomotor axon reflex testing, after iontophoresis (2 mA for 5 min) with ACH, was performed to determine directly activated (DIR) and axon reflex-mediated (AXR) sweating during ACh iontophoresis. The sweat rate, activated sweat gland density, sweat gland output per single gland activated, as well as oral and skin temperature changes were measured. The post exposure activity had a short onset time (p<0.01), higher active sweat rate [(AXR (p<0.001) and DIR (p<0.001)], higher sweat output per gland (p<0.001) and higher transepidermal water loss (p<0.001) compared to the pre-exposure measurements. The activated sweat rate in the sudomotor activity increased the output for post-exposure compared to the pre-exposure measurements. The results suggested that post-exposure activity showed a higher active sweat gland output due to the combination of a higher AXR (DIR) sweat rate and a shorter onset time. Therefore, higher sudomotor responses to ACh receptors indicate accelerated sympathetic nerve responsiveness to ACh sensitivity by exposure to environmental conditions.

Effect of the Heat-exposure on Peripheral Sudomotor Activity Including the Density of Active Sweat Glands and Single Sweat Gland Output

이정범,김태욱,신영오,민영기,양훈모 대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.5

Tropical inhabitants are able to tolerate heat through permanent residence in hot and often humid tropical climates. The goal of this study was to clarify the peripheral mechanisms involved in thermal sweating pre and post exposure (heat-acclimatization over 10 days) by studying the sweating responses to acetylcholine (ACh), a primary neurotransmitter of sudomotor activity, in healthy subjects (n=12). Ten percent ACh was administered on the inner forearm skin for iontophoresis. Quantitative sudomotor axon reflex testing, after iontophoresis (2 mA for 5 min) with ACH, was performed to determine directly activated (DIR) and axon reflex-mediated (AXR) sweating during ACh iontophoresis. The sweat rate,activated sweat gland density, sweat gland output per single gland activated, as well as oral and skin temperature changes were measured. The post exposure activity had a short onset time (p< 0.01),higher active sweat rate [(AXR (p< 0.001) and DIR (p<0.001)], higher sweat output per gland (p <0.001) and higher transepidermal water loss (p<0.001) compared to the pre-exposure measurements. The activated sweat rate in the sudomotor activity increased the output for post-exposure compared to the pre-exposure measurements. The results suggested that post-exposure activity showed a higher active sweat gland output due to the combination of a higher AXR (DIR) sweat rate and a shorter onset time. Therefore, higher sudomotor responses to ACh receptors indicate accelerated sympathetic nerve responsiveness to ACh sensitivity by exposure to environmental conditions.

Effect of the Heat-exposure on Peripheral Sudomotor Activity Including the Density of Active Sweat Glands and Single Sweat Gland Output

Lee, Jeong-Beom,Kim, Tae-Wook,Shin, Young-Oh,Min, Young-Ki,Yang, Hun-Mo The Korean Society of Pharmacology 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.5

Tropical inhabitants are able to tolerate heat through permanent residence in hot and often humid tropical climates. The goal of this study was to clarify the peripheral mechanisms involved in thermal sweating pre and post exposure (heat-acclimatization over 10 days) by studying the sweating responses to acetylcholine (ACh), a primary neurotransmitter of sudomotor activity, in healthy subjects (n=12). Ten percent ACh was administered on the inner forearm skin for iontophoresis. Quantitative sudomotor axon reflex testing, after iontophoresis (2 mA for 5 min) with ACH, was performed to determine directly activated (DIR) and axon reflex-mediated (AXR) sweating during ACh iontophoresis. The sweat rate, activated sweat gland density, sweat gland output per single gland activated, as well as oral and skin temperature changes were measured. The post exposure activity had a short onset time (p<0.01), higher active sweat rate [(AXR (p<0.001) and DIR (p<0.001)], higher sweat output per gland (p<0.001) and higher transepidermal water loss (p<0.001) compared to the pre-exposure measurements. The activated sweat rate in the sudomotor activity increased the output for post-exposure compared to the pre-exposure measurements. The results suggested that post-exposure activity showed a higher active sweat gland output due to the combination of a higher AXR (DIR) sweat rate and a shorter onset time. Therefore, higher sudomotor responses to ACh receptors indicate accelerated sympathetic nerve responsiveness to ACh sensitivity by exposure to environmental conditions.

온돌난방에서 경량기포콘크리트의 재료배합에 따른 방열성능 평가

임재한(Lim Jae-Han) 대한건축학회 2008 대한건축학회논문집 Vol.24 No.2

Normally, the lightweight foamed concrete is used for insulation layer and levelling layer in radiant floor heating. By changing the ratio of ingredients such as an admixture, the fundamental properties of the lightweight foamed concrete could be changed. Due to the conductivity of this material, the characteristics of thermal output could be changed. So this study was aimed to evaluate the thermal output in radiant floor heating due to the mixture of materials in an aerated concrete. Firstly, the current foreign standards regarding the thermal output of radiant floor heating were reviewed. Nextly, the conductivity of lightweight foamed concrete was measured when the admixture and stabilizing agent were added for performance improvements. Finally, thermal output and downward heat loss were evaluated by changing the design parameter such as pipe spacing and water temperature differences. As the results, we could conclude that the conductivity of lightweight foamed concrete could be lowered by 0.12W/mK compared to the KS F 4039. Also the downward heat loss could be lowered by 20%.

Efficiency Improvement of an Automotive Alternator by Heat Treatment

Ji-Hyun Kim,Jung-Pyo Hong 한국자기학회 2015 Journal of Magnetics Vol.20 No.2

Recently, CO₂ emission standards and fuel efficiency legislation has been tightened globally. Therefore automotive alternator performance becomes increasingly important to meet the requirements. Many proposed methods have suggested adding magnets or regulation control to increase alternator efficiency and output. However, this creates a significant additional cost. During the stator lamination process, the magnetic property of the stator deteriorates mainly due to stamping and slinky process for an alternator. To maximize the alternator performance, heat treatment of the stator core was performed and magnetic properties were compared to find the optimal condition. Finally, alternator output and efficiency test were performed resulting in significant output and efficiency improvement up to 6.8% and 0.6% respectively.

The influence of water and steam injection on the performance of a recuperated cycle microturbine for combined heat and power application

Lee, Jong Jun,Jeon, Mu Sung,Kim, Tong Seop Elsevier 2010 APPLIED ENERGY Vol.87 No.4

<P><B>Abstract</B></P><P>Microturbines are promising power sources for small scale combined heat and power (CHP) systems. However, the power output and efficiency of microturbines decreases much as the ambient temperature increases. As a remedy to minimize the performance penalty at hot ambient conditions, the injection of water or steam into a microturbine CHP system was analyzed in this work. An analysis program to simulate the operation of a microturbine CHP system was set up and validated by using measured test data. The injection of hot water, which is generated at the heat recovery unit, at two different locations inside the microturbine was predicted. The generation of steam through the same heat recovery unit and its injection at the two locations was predicted as well. All the four cases provide sufficiently enhanced power output. Injection at the recuperator inlet exhibits a higher efficiency than injection at the combustor in both water and steam injections. Steam injection provides a higher power generation efficiency than water injection on the average. The injection of steam at the recuperator inlet is most promising in terms of power generation efficiency. However, water injection at the recuperator also enhances power generation efficiency while still providing thermal energy to some extent.</P>

MgO/H2O계 화학식 열펌프의 열적 특성에 관한 연구

권오경,윤재호,김정욱,이진호,加藤之貴 대한설비공학회 2004 설비공학 논문집 Vol.16 No.1

The chemical heat pump based on the Dehydration/Hydration process with a MgO/H2O system has been researched. The reactor bed could be expected to store the heat around 200∼370℃ by the dehydration reaction and to release the heat around 100∼160℃ by the hydration reaction under the heat amplification mode operation. The heat output rate of the heat pump system was evaluated using the experimentally determined parameters. The results show that 6∼50 W/kg of heat output and 0.5∼0.8 of heat recovery ratio are attainable. The heat pump will be applicable for a load leveling in a co-generation system by chemical storage of surplus heat at low heat demand and by supplying heat in the peak load period.

강판 마감형 조립식 벽패널 복사냉난방시스템의 냉난방 방열 특성 평가

임재한(Lim, Jae-Han),구보경(Koo, Bo-Kyoung),김성임(Kim, Sung-Im),송승영(Song, Seung-Yeong) 한국태양에너지학회 2013 한국태양에너지학회 논문집 Vol.33 No.2

Recently the radiant panel heating and cooling system has been regarded as an alternative of low temperature heating and high temperature cooling by applying the renewable energy sources to the heating and cooling of buildings. Especially this system can be used as HVAC system alternatives in super high-rise buildings for energy saving and thermal comfort. Also it can be possible to reduce the plenum space because the minimum ventilation air will be supplied into the space. This study focused on the evaluation the basic characteristics of thermal output in prefabricated steel wall panel system for radiant heating and cooling. In order to evaluate the thermal output according to both various supply water temperatures and supply water flow rates, three-dimensional dynamic heat transfer analysis was performed. As results, for the heating mode, thermal output increased by 26% with the supply temperature increasing by 5℃. The surface temperature of panels range within 1~3℃. For the cooling mode, thermal output decreased by 18.2% with the supply temperature increasing by 2℃. The surface temperature of panels range within 0.5~1℃ and it was shown the even temperature distribution.

국내 공동주택의 난방부하 특성을 고려한 바닥 복사난방 패널의 설계

이윤정(Lee Youn-Jung),정창호(Jeong Chang-Ho),여명석(Yeo Myoung-Souk),김광우(Kim Kwang-Woo) 대한건축학회 2011 대한건축학회논문집 Vol.27 No.9

The change of heating load for domestic residential buildings was analyzed in this study. For this purpose, the change of heat transmission coefficient was studied and the heating load was calculated. Although the heating load in domestic residential buildings has been reduced, these circumstances have not been applied to floor heating panel design. In this study, the reasonable design of a heating panel based on an analysis of relation between heat output and design factors of a heating panel was suggested. According to the results, considering the actual heating load, a wider pipe pitch, a smaller pipe size, and a lower water temperature than those at present could be applied to the heating panels of residential buildings.