• Title/Summary/Keyword: central heating

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Vertical arrangement of coils for efficient cargo tank heating

  • Magazinovic, Gojko
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.2
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    • pp.662-670
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    • 2019
  • Tanker cargo tanks are equipped with the means of raising and maintaining the cargo discharge temperature to a suitable level. In this paper, a new heating coil design is proposed and analyzed. Contrary to conventional designs, wherein the heating coils are evenly distributed over the tank bottom, the proposed design arranges the heating coils in the central part of the tank bottom, in a vertical direction. Due to the intensive cargo circulation generated, a forced convection is superimposed on a buoyancy-driven natural convection, providing a more efficient mixed convection heat transfer mechanism. Numerical simulations performed by using a finite volume method show that in the case of 7-bar steam Bunker C heavy fuel oil heating, a five-hour circulation phase average heat transfer coefficient equals 199.2 W/m2K. This result might be taken as an impetus for the more thorough experimental examination.

Alternative Strategies to Central Heating Ventilation and Air Conditioning

  • Shrestha, Pramen P.;Prgada, Mythili
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.401-407
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    • 2022
  • Central heating, ventilation and air conditioning (HVAC) is one of the largest consumers of energy in the residential sector. This project explores the use of multiple HVAC units and/or Zoning in a single residence to reduce energy loads. The energy consumption data of a detached single-family home using two HVAC units, one primary for the main house and a secondary HVAC for a casita, was collected for the same month for two consecutive years, along with details related to the outdoor temperature and the square footage being air-conditioned by each HVAC. A regression algorithm was trained using the above details to find the relation between the parameters. Next, based on the occupancy and usage patterns, the HVAC was redesigned assuming more area under the secondary HVAC unit. The trained algorithm was then used to make energy usage predictions for the revised primary HVAC area, with the assumption that the secondary HVAC unit was turned off. The results were compared with existing energy usage data. It was determined that there were significant energy savings in the second scenario. It is expected that this study and its findings will help future research projects explore more ideas as alternatives to central HVAC, in improving the economic viability of existing options, and in developing a savings calculation tool that will help consumers make informed decisions on their best alternatives to central HVAC.

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A Study on the space organization of Korean-Chinese single family housing at the urban area in Liaoning Province, China (중국 요녕성 조선족 도시단독주택의 공간구성에 관한 연구)

  • 김종영
    • Journal of the Korean housing association
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    • v.11 no.1
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    • pp.125-135
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    • 2000
  • Recently, the space organization of Korean-Chinese houses is different from that of other territories. The vast land of China, coming from different hometown in Korean peninsula, and the different hometown in Korean peninsula, and the different procedure of settlement seem to make the different space organization of Chinese-Korean single family housing at the urban area in Liaoning Province.The characteristics of the Korean-Chinese space organization of single family housing at the urban area in Liaoning Province are as follows;i)Three types of space organization are central kitchen type, central corridors types, and central living room type. ii)The central kitchen type is mainly in old urban housing, after 1980's, the central corridor type appears in single family housing, and central living room type appears 1990's.iii) It seems that the main reason to change the space organization are fuel, system of heating, influence of Korea housing. Especially, Korean-Chinese like central living room type that is suitable for sit down living style. This central living room type supposes to be used as popular space organization in urban housing.

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Effects of High Temperature Heating on the Some Physicochemical Properties of Korean Red Ginseng (Panax ginseng C.A. Meyer) Water Extract (고온 열처리가 홍삼물추출물의 이화학적 특성에 미치는 영향)

  • Kwak, Yi-Seong;Choi, Keum-Hee;Kyung, Jong-Soo;Won, Jun-Yeon;Rhee, Man-Hee;Lee, Jae-Gon;Hwang, Mi-Sun;Kim, Seok-Chang;Park, Chae-Kyu;Song, Kyung-Bin;Han, Gyeong-Ho
    • Journal of Ginseng Research
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    • v.32 no.2
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    • pp.120-126
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    • 2008
  • This study was carried out to investigate the some physicochemical properties of Korean red ginseng (Panax ginseng C.A. Meyer) water extract (RGWE) after heated with high temperatures above $100^{\circ}C$ for 2 hours. RGWEs were heated at 100, 110 and $120^{\circ}C$ for 2 hours by using autoclave. After RGWEs were heated at high temperature for 2 hours without not adjustment of pH, the changes of saponin, free sugars, mineral and color in the RGWEs were investigated. Total ginsenoside content in control was 1.99%, while those of RGWE were 1.65, 1.49 and 1.29% when treated at 100, 110 and $120^{\circ}C$, respectively. The contents of total ginsenoside showed decreased tendency as heating temperatures were increased. The ginsenoside-$Rh_{2}$ and $-Rg_{3}$, which have been reported as very stable red ginseng ginsenosides, showed relatively strong spots on TLC when RGWEs were heated at 110 and $120^{\circ}C$. In case of free sugars in RGWEs, fructose, glucose and maltose showed high contents when compared with control, while Fe, Ca and Mg ions showed very low contents. Value of L in RGWE treated with high temperature was almost the same with control, while values of a and b were increased. Values of a were increased from -0.86 of control to +0.04, +0.05 and +1.14 when treated with 100, 110 and $120^{\circ}C$, respectively. Values of b also were increased from 27.68 of control to 33.61, 33.61 and 37.42 when treated with 100, 110 and $120^{\circ}C$, respectively. Values of total color in RGWEs treated with high temperatures, E, were finally increased by values of a and b.

Effects of pH and High Temperature Treatment on the Changes of Major Ginsenosides Composition in Korean Red Ginseng Water Extract (pH 및 고온 열처리가 홍삼물추출물의 주종 사포닌 성분변화에 미치는 영향)

  • Choi, Keum-Hee;Kwak, Yi-Seong;Rhee, Man-Hee;Hwang, Mi-Sun;Kim, Seok-Chang;Park, Chae-Kyu;Han, Gyeong-Ho;Song, Kyung-Bin
    • Journal of Ginseng Research
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    • v.32 no.2
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    • pp.127-134
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    • 2008
  • This study was carried out to investigate the changes of ginsenosides composition in Korean red ginseng water extract (RGWE) after heated with high temperatures above $100^{\circ}C$. RGWEs were adjusted with pH 3.0, pH 7.0 and pH 10.0, respectively, and then heated at 100,110 and $120^{\circ}C$ for 30 minutes by using autoclave. Total ginsenosides of RGWE treated with heating showed decreasing tendency when compared with control. By TLC analysis, decreasing effect of ginsenosides in RGWE were significantly observed in the acidic condition of pH 3.0, particulary. By HPLC analysis, total ginsenoside of control showed 1.89%, while those of RGWE treated with 100, 110 and $120^{\circ}C$ showed 1.22, 1.05 and 0.97%, respectively. The ratio of protopanaxadiol (PD) to protopanaxatriol (Pr) saponins in control was 1.89, while that of PD/PT in treated RGWEs were level of 1.33 to 1.47. By the result of decreased ratio of PD/PT in RGWE, it was considered that PD type saponin such as ginsenoside$-Rb_{1}$, $-Rb_{1}$, -Rc and -Rd was more unstable than PT type saponin such as ginsenoside-Re and Rg against high temperature heating above $100^{\circ}C$.

An Analysis on Building Energy Load along Core Position, Area Ratio and Orientation (코어 위치와 종횡비 및 방위에 따른 건물 에너지 부하 분석)

  • Kim, Jin-Ho;Park, Woo-Pyoung;Shin, Seung-Ho;Min, Joon-Ki;Kim, Dong-Hoon
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.9 no.1
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    • pp.15-19
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    • 2013
  • In this Study, effect of core position, area ratio and orientation of building on energy load is examined using TRNSYS17. This parameters are major parameters of the conceptual design stage. Reference model is square floor plan($1,444m^2$), centered core and 29% core area ratio. As the results, without considering the building orientation, the annual heating load of central building with 1:1 area ratio is lowest ($10.33kWh/m^2yr$) and the annual cooling load of off-central building with 1:1 area ratio is lowest ($59.27kWh/m^2yr$). As area ratio is bigger, cooling load is lower and heating load is higher. But if we consider building orientation, orders of heating load and cooling load are changed for area ratio and orientation.

Improvement of Thermal Enviromental by Two Air Out in Hot Air Heating (이중 취출구에 의한 온풍난방시의 열환경 개선)

  • Jang, In-Seong;Kim, J.S
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.33 no.3
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    • pp.209-217
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    • 1997
  • The objective of this paper is to improve a discomfort caused by the unequal airflow and vertical temperature difference by buoyancy of the supplied hot air in the conventional hot air heating system. In order to the model experiment we manufactured the hot air heater with two air outlet and a model room. We observed the temperature, velocity and airflow distribution and calculated values of PMV and PPD using mean value of central verticality section's air temperature and velocity. We could improve distribution of vertical temperature and velocity at the central section of the model room owing to correlation of hot air of two air outlet.

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Application study of heat storage type GSHP system in Apartment building with central cooling and heating facilities using life cycle cost analysis (LCC 분석을 이용한 중앙공급식 공동주택의 수축열식 지열원 히트펌프시스템의 적용연구)

  • Lee, Sang-Hoon;Park, Jong-Woo;Cho, Sung-Hwan
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.1497-1502
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    • 2009
  • The present study has been conducted economic analysis of heat storage type ground source heat pump system(HSGSHP) and normal ground source heat pump (GSHP) and central boiler system with individual air conditioning facility which are installed at the same building in the shared an apartment house. Cost items, such as initial construction cost, annual energy cost and maintenance cost of each system are considered to analyze life cycle cost (LCC) and simple payback period (SPP) with initial cost different are compared. The initial cost is a rule to the Government basic unit cost of production. LCC applied present value method is used to assess economical profit of both of them. Variables used to LCC analysis are prices escalation rate and interest rate mean values of during latest 10 years. The LCC result shows that HSGSHP (1,351,000,000won) is more profitable than central boiler system with individual air conditioning facility by 86.7% initial cost. And SPP appeared 8.0 year overcome the different initial cost by different annual energy cost.

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Thermal Performance Assessment of Wet Ondol and Electric Ondol System (습식온돌시스템과 전기온돌시스템의 열성능 평가)

  • Han, Byung-Jo;Koo, Kyung-Wan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.1
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    • pp.214-220
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    • 2011
  • This paper studies about the assessment of thermal performance between wet ondol system and electric ondol system. Electrical ondol systems shows faster warm-up time, higher floor surface temperature distribution and lower power consumption than wet ondol system. However, if we provide heat regularly wet ondol system which has more heat capacity shows greater thermal storage than electric ondol system. Therefore, we could conclude that wet ondol system which keeps temperature regularly by the thermal storage show better energy-efficiency in case of using the central heating and district heating system. However, Electrical ondol system shows better efficiency in case of using the space during short time or individual heating systems which needs to heat quickly. The Experiment says that electric ondol system has more benefits on timing to reach the set temperature and energy-efficiency than wet ondol system.

Improvement Method of Regional Insulation Standard through the Regional Heating Energy Demand Analysis (권역별 난방에너지 요구량 분석을 통한 단열기준 개선방안)

  • Kim, Jeong-Gook;Ahn, Byung-Lip;Jang, Cheol-Yong;Jeong, Hak-Geun;Haan, Chan-Hoon
    • KIEAE Journal
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    • v.13 no.4
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    • pp.43-48
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    • 2013
  • The effect of climate change has influenced humanity and ecosystem with tremendous changes in temperature. For the past 150 years, the national annual average temperature is 0.6 degree increased and the heating degree day reduced from April to November. However, December to January, the climate change was generated and the heating degree day increased. The blackout occured in 2011 and 2012 by increasing electricity consumption of heating and cooling equipment to the effects of climate change. That is because heating load accounted for 20% of building electric use. In this study, strengthening measures to reduce heating energy consumption is presented due to climate change in winter since 1980 to prevent blackout and reliable power supply for the building energy-saving design standards by Meteorological data provided by the National Weather Service were calculated using the heating degree days in order to present eighteen cities from 1980 to 2012. Insulation standards are presented to prevent black-out by the heating degree days. the heating energy demand was reduced almost 6% including 10% in Central, 5% in South and Jeju area based on strengthening of the insulation. It is applied to the entire country an annual economic effect of 250 billion won, and black-out can be prevented.