• Title, Summary, Keyword: Waste heat

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A Study on the Consumers' Perception of Agricultural Products Using Nuclear Power Plants Waste Heat (원자력 발전소 온배수 이용 농산물에 대한 소비자 인식조사)

  • Heo, Seung-Wook
    • Korean Journal of Organic Agriculture
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    • v.26 no.3
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    • pp.369-379
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    • 2018
  • This study examines consumers' perception of agricultural products using nuclear power plants waste heat. This study surveyed 348 consumers and found that presenting information about safety of waste heat utilization increased appropriacy of waste heat; after providing the information, the percentage of respondents in favor of using waste heat increased 27.5% point from 38.3% to 65.8%. The most important reason against using waste heat was because it threatened the safety of agricultural products, and the most important reason for its support was to reduce farm production costs. The purchase intention for agricultural products using waste heat had risen by at least 10% point after providing the information about safety of waste heat. Those means that it important provision of accurate and reliable information on the safety of waste heat to encourage the utilization of waste heat from nuclear power plants. Purchase intention for flowers using waste heat was most, followed by vegetables, fruits (including fruits and vegetables).

An Investigation Study on Fact of Waste Heat of Domestic Industry (국내 산업폐열 현황에 대한 조사연구)

  • 박일환;박준태;유성연
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.10
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    • pp.811-816
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    • 2002
  • Waste heat exhausted from seven types of the domestic industry was surveyed, which include food, fibre, paper & wood, chemical, ceramics, metalworking and others. The databases of waste heat for each industry were made by using ACCESS software of Microsoft, and data were analyzed to get correlation between waste heat and purchase energy. The volume of usable waste heat is estimated to be 9,169,000 TOE in the year of 2000, when the minimum available temperature is set as $100^{\circ}C$ for waste gas, $30^{\circ}C$ for hot water and $100^{\circ}C$ for steam considering the condition of waste heat exhausting facilities and surroundings. This volume of waste heat is approximately 11.9 percent of the purchase energy of the domestic industry.

A Study on the Characteristics of Waste Heat from the Industrial Complexes for Residential and Commercial Sectors (가정.상업부문 이용을 위한 산업체 폐열특성 연구)

  • 최영찬;박태준;홍재창;조선영
    • Journal of Energy Engineering
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    • v.8 no.2
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    • pp.242-247
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    • 1999
  • The characteristics of waste heat effluents from 11 industrial complexes of 7 areas were analyzed to investigate the possibility of waste heat recovery of huge amount of waste heat producing from various industrial complexes. This study presents a part of the research work for the industrial waste heat for development of energy integrated network system in broad city area, which will utilize industrial waste heat for residential and commercial areas, where they are located at some distances from the complexes. The amount of waste heat from the investigated complexes was detected as 148,913 TOE/year. However, It was analyzed 83% of the waste heat was analyzed the temperature range from 0$^{\circ}C$ to 200$^{\circ}C$. Also, it was evaluated that 82% of waste heat was exhausted by flue gases. Especially, the characteristics of waste heat for the areas where most heat concentrated, such as Tae-gu industrial complex, Ul-san petrochemitry complex, Yio-chun petrochemistry complex, and Chun-ju industrial complex were investigated more precisely. Total amount of waste heat discharged from these four areas were analyzed 114,402 TOE/year, which was occupied as 77% of the total waste heat for the studied areas, and 87% of the waste heat from the industries was exhausted by flue gaseous phase and temperature range was from 0$^{\circ}C$ to 200$^{\circ}C$ 18.1 million TOE/year waste heat was released from the fossil fuel power plants, however 95% of waste heat was analyzed as cooling water from surface condensers at power plants. The temperature range was measured from 27$^{\circ}C$ to 34$^{\circ}C$, which are unable to utilize due to its low temperature. Otherwise, 5% (894,800 TOE/year) waste heat released from power plants were observed as flue gas, which temperature ranged from 90$^{\circ}C$ to 170$^{\circ}C$.

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Design of an Intelligent Controller for Waste Water Heat Pump Recycled Energy Systems

  • Choo, Yeon-Gyu
    • Journal of information and communication convergence engineering
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    • v.9 no.4
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    • pp.375-378
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    • 2011
  • This study is intended to realize an intelligent controller using fuzzy control algorithms in order to recycle energy by recycling the waste water heat discharged by waste water heat collection boilers. Using waste water inflow temperature changes and waste water inflow amount changes as parameters, we present characteristic curves of the number of compressors being operated at fixed speeds and the temperature of hot water being discharged. We propose an intelligent controller that determines the optimum number of compressors being operated at fixed speeds in real time by measuring changes in the temperature and amount of waste water inflows in order to minimize the number of compressors being operated at fixed speeds relative to the waste water load flowing into the waste water heat collection boiler.

A Evaluation on Drying Performances of Hydrothermal Carbonization of Sewage Sludge by using Low-grade Heat Source (저온 열원 활용 디스크 건조기를 이용한 하수슬러지 수열탄화물 건조 효율 평가)

  • Jung, Sang-chul;Shin, Myung-seop;Jeon, Yong-woo
    • Journal of Korea Society of Waste Management
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    • v.35 no.6
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    • pp.507-514
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    • 2018
  • The treatment of sewage sludge using hydrothermal carbonization (HTC) can be an attractive alternative to conventional sludge disposal, but it should be accompanied by a drying process that uses Refuse-derived Fuel (RDF). However, the largest proportion of the energy demand in sludge-drying techniques is for heat sources, which has led to increased operation and maintenance costs. Recovering residual heat to apply to sludge drying significantly reduces both the operating cost and the greenhouse gas emissions. Suitable integration can be realized between drying technology and waste-to-energy (WtE) plants through the recovery of waste heat in WtE conversion as a heat source for sludge drying. This present paper investigates the indirect disk drying performance of the hydrothermal carbonization of sewage sludge using a low-temperature heat source in a laboratory and proposes an integration process with the drying technology of hydrothermal carbonization using waste heat. This paper concludes with experimental results that indirect disk drying technology can be applied in waste-heat recovery systems.

Performance Test of Low Temperature Waste Heat Recovery Heat Exchanger Using Self-excited Oscillating Heat Pipe (자려 진동형 히트 파이프를 이용한 저온 폐열 회수 열교환기의 성능 실험)

  • 이욱현;이종현;김종수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.9
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    • pp.853-859
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    • 2000
  • In this study, low temperature waste heat recovery heat exchanger was developed using a principle of self-excited oscillating heat pipe. The heat exchanger of serpentine type was composed of extruded flat aluminum tube with 6 channels (3 nm$\times$ 2.75nm) and louvered fin. The heat transfer area density of heat exchanger was $331.9 m^2/m^3$. Working fluid is R141b and charge ratio was 40% by volume. Heat transfer rate and the effectiveness of heat exchanger was primary concern of this study. As a result, the effectiveness of heat exchanger was about 0.4-0.67, and recovered waste heat rate was about 4.5 kW per one unit of heat exchanger.

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Conceptual design of an expander for waste heat recovery of an automobile exhaust gas (자동차 배기가스 폐열 회수용 팽창기 개념설계)

  • Kim, Hyun-Jae;Kim, You-Chan;Kim, Hyun-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • pp.237-242
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    • 2009
  • A steam Rankine cycle was considered to recover waste heat from the exhaust gas of an automobile. Conceptual design of a swash plate type expander was practiced to convert steam heat to shaft power. With the steam pressure and temperature of 35 bar and $300^{\circ}C$ at the expander inlet, respectively, the expander was estimated to produce the shaft power output of about 1.93 kW from the exhaust gas waste heat of 20 kW. The expander output increased linearly accordingly to the amount of exhaust gas waste heat in the range of from 10-40 kW, and the Rankine cycle efficiency was more or less constant at about 9.6% regardless of the waste heat amount.

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An Experimental Study on Thermoelectric Generator Performance for Waste Coolant Recovery Systems in Vehicles (자동차 냉각수 폐열회수 열전발전 시스템의 성능에 관한 연구)

  • Lee, Dae-Woong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.7
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    • pp.329-334
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    • 2014
  • This study indicated the possibility of energy regeneration from waste coolant heat, by using thermoelectric generation integrated with heat pipe. The internal combustion engine rejects more than 60% wasteful energy to the atmosphere by heat. The thermoelectric generator has recently been studied, to convert the energy from engine waste heat into electricity. For coolant waste heat recovery, a thermoelectric generator was investigated, to find out the possibility of vehicular application. Performance characteristics were conducted with various test conditions of coolant temperature, coolant mass flow rate, air temperature, and air velocity, with the thermoelectric generator installed either horizontally or vertically. Experimental results show that the electric power and conversion efficiency increases according to the temperature difference between the hot and cold side of the thermoelectric generator, and the coolant flow rate of the hot side heat exchanger. Performance improvement can be expected by optimizing the heat pipe design.

A study on the steam boiler with high compression waste heat recovery system (고압축 폐열회수장치를 구비한 증기보일러에 관한 연구)

  • HAN, Kyu-il;CHO, Dong-Hyun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.3
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    • pp.302-307
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    • 2017
  • An electric steam boiler equipped with a condensate recovery system, which stores the condensate generated after using steam in steam washers, steam cookers, steam irons, and steam cleaners in a condensate tank and supplies compressed air to the condensate tank so that the condensate is recovered to the boiler by the pressure of the compressed air, was studied. In the results of this study, the heat energy balance between the quantity of the heat generated by the non-metallic surface heating element and the quantity of the heat absorbed by the water was good in a range of ${\pm}5%$. In addition, the heat transfer rate increased in proportion to the electric power of the surface heating element heater, the waste heat energy was normally recovered by the recovery of the condensate of the steam boiler equipped with the high compression waste heat recovery system, and the recovery rate of the waste heat exhibited 23%.

Effect of Heat Treatment on the Start-up Performance for Anaerobic Hydrogen Fermentation of Food Waste (음식폐기물을 이용한 혐기성 수소 발효 시 초기 운전 성능에 대한 열처리 효과)

  • Lee, Chae-Young;Lee, Se-Wook;Hwang, Sun-Jin
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.6
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    • pp.765-771
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    • 2011
  • This study was conducted to investigate the effect of heat treatment on the start-up performance for anaerobic hydrogen fermentation of food waste. The result showed that hydrogen production was $0.61{\pm}0.31$ mol $H_2$/mol hexose with heat-treatment of food waste at $70^{\circ}C$ for 60 min whereas it was $0.36{\pm}0.31$ mol $H_2$/mol hexose without heat-treatment of one. The heat treatment of food waste enhanced hydrogen yield due probably to the increase of hydrolysis as well as the decrease of non-hydrogen fermentation microorganisms. The removal efficiency of carbohydrate in reactors regardless of heat treatment of food waste maintained over 90%. The hydrogen conversion efficiency from food waste was 1.7-6.3% with heat-treatment whereas it was 0.7-4.5% without heat-treatment. At the time of switchover from batch to continuous operation, lactate concentration was high compared to the n-butyrate concentration in anaerobic hydrogen fermentation reactor without heat-treatment. Anaerobic hydrogen fermentation of food waste with heat treatment was stable in start-up periods because lactate concentration could be maintained at a relatively low compared to n-butyrate concentration due to the decrease of non-hydrogen fermentation microorganisms.