• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.2
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• pp.117-124
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• 2005

Aluminum plate heat exchanger, rotary wheel heat exchanger, and heat pipe heat exchanger have been used (or ventilation heat recovery in the air-conditioning system. The purpose of this research is to develop high efficiency plastic plate heat exchanger which can substitute aluminum plate heat exchanger. Because thermal conductivity of plastic is quite small compared to that of aluminum, various heat transfer enhancement techniques are applied in the design of plastic plates. Five types of heat exchanger model are designed and manufactured, which are plate type, plate-fin type, turbulent promoter type, corrugate type, and dimple type. Thermal performance and pressure loss of each heat exchangers are measured in various operating conditions, and compared each other. Test results show that heat transfer performance of corrugate type, turbulent promoter type, and dimple type are increases about $43\%$, $14\%$, and $33\%$ at the equivalent fan power compared to those of plate type, respectively. On the other hand, the heat transfer performance of plate-fin type decreases $9\%$ because fins can not play their own role.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.9
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• pp.839-848
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• 2005

Plastic plate heat exchangers have many advantages over the conventional heat exchangers such as aluminum plate heat exchangers, rotary wheel heat exchangers and heat pipe heat exchangers which have been used for ventilation heat recovery in the air-conditioning systems. In the present study, pressure drop and heat transfer characteristics of plastic plate heat exchangers are investigated for various design parameters and operating conditions which affect the performance of the plastic plate heat exchangers. In flat plate type heat exchanger, material thickness and channel height of heat exchanger are considered, and corrugate size and heat transfer area are considered in case of corrugate type heat exchanger. Pressure drop and effectiveness of the corrugate type heat exchanger increase as the corrugate size decreases.

• Journal of Energy Engineering
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• v.21 no.4
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• pp.393-397
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• 2012

In this study, an organic Rankine cycle(ORC) for gas engine waste heat recovery for industry has been constructed and a performance analysis test has been carried out. Shell & tube style heat exchanger has been equipped on an engine exhaust manifold in order to absorb heat of engine exhaust gas into the working fluid(refrigerant R134a). Under 60 kW of engine power output, about 63 kW of engine exhaust gas heat was discharged and the proportion of heat recovered was 68~73% while 43~46 kW of heat was absorbed into working fluid. Consequently rated power output of ORC was 4.6 kW while the ratio of rated power output to engine exhaust gas heat was 7.3%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.56-66
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• 2021

In this study, a waste heat recovery system was devised and the performances of components incorporated to recover the heat generated during the processing of aerobic liquid-composting in a livestock manure treatment facility were analyzed. In addition, the availability of recovered heat was confirmed. The heat generated by liquid fermentation in the livestock manure treatment facility was also checked. Experimental temperatures were set at 35, 40, and 45 ℃ based on considerations of the uniformity of aerobic liquid-composting fermentation tank temperature and its operating range (34.5 ~ 43.9 ℃). Recovered heat energies from the combined heat exchanger, which consisted of PE and STS pipes, were 53.5, 65.6, 74.4 MJ/h, The heat pump of capacity 5 RT was heated at 95.6, 96.1, 98.9 MJ/h and the heating COPs of the pump were 4.53, 4.62, and 4.65, respectively. The maximum hot water production capacity of the heat exchanger assuming a fermentation tank temperature of 45 ℃ confirmed an energy supply of 56 360 kcal/day. The heating capacity of the FCU linked to the heat storage tank was 20.8 MJ/h, and the energy utilization efficiency was 96.1%. When livestock manure was dried using the FCU, it was confirmed that the initial function rate was reduced by 50.5 to 45.8 % after drying.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1197-1203
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• 2004

This study investigates the air leakage and heat transfer characteristics of a rotary-type air-to-air heat exchanger with a fiber polyester matrix. The leakage airflow rate is measured using a tracer gas method for various ventilation rates and rotational speeds of the matrix wheel. A correlation equation for air leakage is obtained by combining the pressure leakage and the carryover leakage. The pressure leakage is observed to be a function of ventilation airflow rate only, and the carryover leakage is found to be a linear function of rotational speed. The real efficiency of the heat exchanger can be obtained from its apparent efficiencies by taking into account the air leakage ratio. As the ventilation rate increases, the heat recovery efficiency decreases. As the rotational speed of the matrix increases, the efficiency increases initially but reaches a constant value for the rotational speeds over 10 rpm.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.174.2-174.2
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• 2011

최근 유가상승과 석유, 천연가스의 가채 매장량의 한계등과 함께 온실가스에 의한 지구온난화 방지를 위하여 미국, 유럽국가 및 캐나다 등에서는 바이오매스를 이용한 에너지 회수 기술개발에 많은 관심과 연구를 수행하고 있다. 바이오 매스는 에너지 밀도 대비 존재하는 지역이 광범위하여 발생, 수집, 수송에 따른 비용이 많이 소요되는 특성이 있어 산지에서 직접처리하거나 수집하여 대규모처리등과 같이 여러 가지 현장상황에 따라 적정한 플랜트 운용의 유연성을 갖추고 있어야 한다. 일반적으로 바이오매스로부터 중소형으로 분산형 발전이나 수소제조를 위해서는 직접 연소법 보다는 가스화 방식을 이용하고 있는데, 연소에 의해 열을 생산하여 전기를 생산하는 방식은 스팀터빈을 이용하는 것이며, 스팀터빈은 소형 운용이 어렵기 때문이다. 본 연구에서는 폐목재로부터 합성가스제조를 위하여 5톤/일 규모 가스화기를 제작하였으며, 타르 및 수트와 같은 미반응 물질을 제거할 수 있는 집진, 세정장치를 설계 및 제작하였다. 또한 합성가스에 함유된 현열로부터 열회수를 위하여 열교환기를 설치하였으며, 정제된 합성가스를 이용하는 가스엔진을 통하여 열병합 발전시스템 연계운전을 수행하였다. 운전 실험을 폐목재 가스화 3톤/일 규모로 수행하였으며, 평균 1,500kcal/$Nm^3$의 발열량을 갖는 합성가스를 생성시킬 수 있었다. 사이클론, 스크러버 및 기수분리 장치를 이용하여 정제된 합성가스는 합성가스 엔진을 통하여 72kW 이상의 전력생산이 가능하였다. 열교환기를 통하여 평균 15,000kcal/h의 배열 회수가 가능하였으며, 바이오매스 가스화 합성가스를 이용한 열병합 발전이 가능함을 입증하였다.

• Journal of the Korea Convergence Society
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• v.10 no.7
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• pp.281-287
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• 2019

Application of heat recovery system applying air supply and cexhaust ventilation device essential in energy management system for the optimum ventilation system utilization and energy saving. This is a key element of infrastructure technology for high-efficiency energy buildings, because it can save heating and cooling energy in winter and summer. In this paper, heat transfer efficiency was simulated using paper, plastic, and aluminum materials that was examined to compare heat exchanger performance under uniform flow conditions. We tested heat transfer efficiengy according to the shape of two of that, one is orthogonal and the other is refraction shape. Based on the simulation results, it is expected to contribute to the production of high performance heat exchanger with heat transfer performance and pressure loss.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.78-84
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• 2012

The purpose of this study is to investigate the performance characteristics of new exhaust heat recovery device for the engine's fast warm-up. In this study, two different interior area designed for prototyping and on the exhaust heat recovery device to evaluate the performance compare the performance characteristics were chosen a better product. A company's product and selected prototype-2 were evaluated and compared the performance. This experiment was conducted under the same conditions. The time from starting to warm-up of engine was measured. As a result, the performance characteristics of the prototype-2 was not higher than that of the A company's product. However, in comparison with base system, prototype-2 of the exhaust heat recovery device discover that the warm-up time was shortened.

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.82-82
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• 2007

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.51-51
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• 2003