• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
• /
• pp.460-463
• /
• 2008

A large part of the overall industrial energy is dissipated as waste heat despite of much development in the utilization of thermal energy. A mean efficiency is reported to be only around 30 to 35%. The existing waste heat recovery technology has reached its limit and consequently, the development of a new technology is necessary. Improving efficiency using thermoelectric technology has recently come into the spotlight because of its unique way to recover thermal energy. In fact, thermoelectric generator directly converts thermal energy into electric energy by a solid state without any moving parts. Futhermore remarkable improvement in the thermoelectric energy conversion efficiency has been achieved. In this study, a thermoelectric generator was made using commercialized thermoelectric modules. With thermoelectric modules attached on a duct surface, hot air was blown into the duct using a hot air blower. On the other side of the module, a water jacket was attached to cool the module. With different air inlet temperatures and water flowrates, the electrical power of the thermoelectric generator was measured.

• 대한조선학회 특별논문집
• /
• 대한조선학회 2013년도 특별논문집
• /
• pp.103-109
• /
• 2013

The Present work focuses on application of Organic Rankine Cycle - Waste heat Recovery System (ORC-WHRS) for marine diesel engine. ORC and its combined cycle with the engine were simulated and its performance was estimated theoretically under the various engine operation conditions and cooling water conditions. The working fluid, R245fa, was selected for the consideration of the heat source temperature, system efficiency and safety issues. According to the thermodynamic analysis, ~13.1% of system efficiency of the cycle was performed and it is about 4% of the mechanical power output of the considering Marine Diesel Engine. Also, addition of evaporator and pre-heater were studied to maximize output power of Organic Rankine Cycle as a waste heat recovery system of the marine diesel engine.

• 설비공학논문집
• /
• 제29권5호
• /
• pp.249-258
• /
• 2017

This paper provides an economic analysis of a new geothermal heat pump system that reuses condenser waste heat from a Ground Source Heat Pump ($GSHP_{ch}$) to provide energy for a hot water Ground Source heat pump ($GSHP_{hw}$). After conducting feasibility tests using GLD and TRNSYS simulations, the proposed system was effectively installed and thoroughly tested. We observe that 1) the Coefficient of Performance (COP) of the $GSHP_{hw}$ and the $GSHP_{ch}$ during cooling mode improves by up to 62% and 7%, respectively; 2) the number of bore holes can be reduced by two; and 3) the hot water supply temperature of the $GSHP_{hw}$ increases by up to $60^{\circ}C$. We further conclude that 1) the reduction of two bore holes can save approximately ten million Won from the initial cost investment; and 2) the increased COP of the $GSHP_{hw}$ can save approximately one million Won in annual electricity costs.

• 전기저널
• /
• 11호통권119호
• /
• pp.40-45
• /
• 1986

• 에너지공학
• /
• 제15권4호
• /
• pp.284-290
• /
• 2006

냉 난방 수요에서 일어나는 환경오염의 최소화와 화석연료 소비를 감소시키기 위해서 에너지 회수를 개선시키는 것은 필수적이다. 이러한 점에서 흡수식 열펌프기술은 에너지 절약을 위해서 많은 가능성을 가지고 있다. 흡수식 열펌프는 에너지를 주입하지 않고 폐열의 이용을 높일 수 있는 방법이다. 본 연구에서는 에너지 회수를 위한 재흡수 열펌프 연군를 메탄올-글리세린을 이용하여 수행하였다. 이 물질의 열역학 데이터를 이용하여 재흡수 열펌프의 이론적 열효율 값을 각 기관의 조업 조건에 따라서 계산하였다. $70{\sim}80^{\circ}C$의 산업 폐열 온도를 가지고 $40{\sim}50^{\circ}C$ 승온 시킬 때 열효율 값 0.4 이상을 얻을 수 있었다.

• 설비공학논문집
• /
• 제15권8호
• /
• pp.690-696
• /
• 2003

This paper presents the heat recovery performance of water fluidized-bed heat exchanger. Temperature and humidity ratio of waste gas are considered as important parameters in this study. Therefore, the heat recovery rate through water fluidized-bed heat exchanger for exhaust gases with various temperatures and humidity ratios can be estimated from the results of this study. Mass flow ratio (the ratio of mass flow rate of water to that of gas) and temperature of inlet water are also considered as important operating variables. Increase of heat recovery rate can be obtained through either high mass flow ratio or low temperature of inlet water with resultant low recovered temperature. The heat recovery performance with the mass flow ratio of about up to 10 has been investigated. The effect of number of stages of water fluidized-bed on the heat recovery performance has been also examined in this study.

• Journal of Advanced Marine Engineering and Technology
• /
• 제36권5호
• /
• pp.595-602
• /
• 2012

본 논문에서는 선박에서 배출되는 $CO_2$ 배출을 최소화하기 위한 노력의 일환으로 선박으로부터 배출되는 열에너지를 회수하고 재활용하는 방안으로 유기랭킨사이클 발전장치를 구동함으로써 선박의 에너지 효율을 높이고 온실가스 배출을 최소화할 수 있는 방안을 연구하였다. 선박에서 배출되는 배기가스와 냉각 시스템에서 배출되는 열에너지를 회수하여 터빈 발전기를 구동하는 ORC 발전시스템을 설계하고 시뮬레이션 하였다. 다양한 친환경 유기냉매를 이용하여 냉매를 적용하여 온도와 유량변화에 따른 열 해석을 실시하였고 냉각수 열원 예열기, 배기가스 가열기로 시스템을 구성하여 2,400kW급의 발전 출력을 얻을 수 있었다.

• 시스템엔지니어링학술지
• /
• 제14권1호
• /
• pp.1-12
• /
• 2018

In the energy-guzzling industries such as steel making and cement, power plants utilizing waste heat have been attracting attention to increase energy efficiency. However, the existing economic analysis system doesn't consider the special working fluids and the cost models of the main equipment used in the waste heat recovery power plant. So it is difficult to estimate the plant economics accurately. Therefore, It is required to develop a economic analysis module that can more accurately evaluate for the power plant. In this study, the systems engineering approach was used to design and develop the module that systematically reflects the characteristics of the power plant and various requirements. Specifically, first, the special working fluids and main equipment applied to the power plant were investigated. Next, the cost models for each equipment were developed. Finally, the economic analysis module based on this was developed.

• 설비공학논문집
• /
• 제15권12호
• /
• pp.979-986
• /
• 2003

The performance characteristics of heating and cooling operation for a heat pump system using seawater heat source and exhaust energy are presented. The heat pump system is made of a waste heat recovery system and a vapor compression refrigeration system. The working fluid is R-22. The heat pump system COPs are measured during heating and cooling operation modes, and the resultant COPs were 9.7 and 7.9, respectively, which are three times higher than those of the heat pump itself. Therefore, the performance of the heat pump system using exhaust energy is excellent compared to that of a general heat pump. The experimental data can be effectively used for the design of the high efficient heat pump using a seawater heat source.

• Journal of Biosystems Engineering
• /
• 제11권2호
• /
• pp.23-30
• /
• 1986

A waste heat recovery system for an internal combustion engine for agriculture was developed. The system is for recovering both of exhaust heat and cooling heat of an engine and is so simple in its structure that can be used in rural area easily. A series of experiment was carried out to the experiment which will be discussed later on, collect data for the performance of the system at various operating conditions of the system and an engine and to determine a range of coolant temperature in which performance of an engine is not affected by the heat recovery system incorporated. The obtained experimental data is not only useful to materialize performance of the system at the experimental conditions but also to construct a mathematical model of the system to predict the system variables beyond the scope of