• Title/Summary/Keyword: 성적계수

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Cycle Simulations for Power Saving BIP(block ice plant) design (절전형 제빙시설 설계를 위한 사이클 모사)

  • Kang, Jong-Ho;Kim, Nam-Jin;Lee, Jae-Yong;Kim, Chong-Bo
    • Proceedings of the KSME Conference
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    • pp.216-221
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    • 2000
  • Most Ice making companies make simple efforts to make products and fail to introduce improvements into the system against huh cost of products. The work presented here is an implementation of ice making method to improve both energy efficiency and productivity. In this present investigation, several ice making cycles are designed and calculated to evaluate COP, ice making time and electric energy consumption. Results obtained shows that COP is improved with more efficient use of time for ice making and electric consumption. Therefore this can offer the opportunity for more efficient energy consumption and productivity in ice making.

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The Performance Investigation of Double-speaker-1/2 Wavelength Thermoacoustic Refrigerator (Double speaker 1/2파장 열음향 냉동기의 성능 평가)

  • Song Kyu Joe;Park Jong Ho;Lee Sung Ro
    • Proceedings of the KSME Conference
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    • pp.647-650
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    • 2002
  • A thermoacoustic refrigerator, using a resonant standing acoustic wave, has been built. It employs a loudspeaker to sustain a standing wave in a resonance tube. The stack of plates is 0.075mm-thick plastic sheet(Mylar), spirally wound to make a 40mm-diameter assembly 80mm long. and two heat exchanger are installed. The refrigerant is Helium gas. The description of thermoacoustic refrigerator are presented. The directly measured performance of the resonator. Tc/Th ( temperature ratio ) and $COP/COP_{c}$, (normalized by carnot's COP ) are plotted versus the thermal load Q applied to the cold end, for various speaker power.

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Development of Optimum High Pressure Algorithm for a Transcritical $CO_2$ Mobile Air-Conditioning System ($CO_2$ 자동차 에어컨 시스템의 최적 고압 설정 알고리즘 개발에 관한 연구)

  • Lee, Jong-Bong;Lee, Jun-Kyoung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.3
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    • pp.159-165
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    • 2008
  • This paper deals with the optimum high pressure control algorithm for a transcritical $CO_2$ mobile air-conditioning system with belt-driven compressor to achieve the maximum COP. The experiments were performed to find out the maximum COP conditions with various operating conditions. The experimental results showed that the COP was increased and then decreased with increase of the refrigerant high pressure for the system. Therefore the value of high pressure which has maximum COP could be selected. Furthermore, the strong (linear) relation between the optimum high pressure and the gas cooler outlet temperature was revealed, which suggests the use of a simple controller with only one parameter for the transcritical $CO_2$ cycle.

A Study on the Operating Characteristics of the Heat Pump System using the Municipal Waste Water as Heat Source (생活廢水熱源 熱펌프시스템 運轉特性 考察)

  • 신현준;박준택
    • Journal of Energy Engineering
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    • v.4 no.2
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    • pp.270-277
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    • 1995
  • 생활수준의 향상으로 따라 민생용 에너지의 소비량이 급격히 증가함에 따라 일상생활에서 발생되는 폐수의 양과 온도가 높아지면서 이들은 주요 에너지자원의 대상으로 부각되고 있다. 즉, 폐수열은 열원으로서의 경제성이 향상되어 에너지자원으로서의 잠재력이 높아지고 있으며, 또한 화석에너지의 과다 사용을 인한 환경오염이 심각한 사회문제로 부각되면서 이들 에너지의 유효이용에 대한 관심이 높아지고 있다. 본 연구는 일상생활에서 발생되는 생활폐수를 대상으로 냉·난방에너지원으로서의 활용 가치를 평가히기 위한 열특성을 파악하고, 이 폐수열을 열원으로 하는 熱펌프시스템을 제작·설치하여 운전 성능을 파악하므로서 장차의 에너지수요에 대응하기 위한 기초자료를 제시하는데 목적이 있다. 이를 위해 아파트 단지를 대상으로 폐수열의 계절별 온도분포를 측정하고, 열원의 특성에 적합한 폐수열교환기, 세척장치 등 요소기기의 구조를 도출하였으며 이를 이용한 熱펌프시스템을 제작하여 성능실험을 수행하였다. 실험결과 난방기의 성적계수(COP)h를 3.5이상으로 유지할 수 있는 비교적 경제성이 높은 熱펌프시스템의 구성이 가능한 것으로 나타났다.

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Performance of a Reciprocating Compressor Equipped with Auxiliary Port (보조 흡입구가 장착된 왕복동 압축기의 성능 분석)

  • Lee, Yong-Ho;Kim, Hyun-Jin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.10
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    • pp.637-644
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    • 2008
  • Auxiliary port which had been known to be used to reduce the expansion loss of a refrigeration system was applied to a R134a reciprocating compressor in a household refrigerator cycle with an intention of improving the compressor performance. Effects of the auxiliary port on the compressor performance was investigated by a computer simulation program. When a simple hole was made on the side wall of the cylinder as an auxiliary port and surrounding gas inside the compressor shell was assumed to be drawn into the cylinder through the hole, maximum COP improvement of 1.66% was obtained. With auxiliary port equipped with a plate type of check valve, maximum COP was raised to be 1.99%. COP improvement was more distinctive with decreasing the discharge pressure; COP improvement was 5% with discharge pressure of 7 bar.

A Study on the Improvement of the Water Source Energy Distribution Regulation for High Efficient Data Center Cooling System in Korea (데이터센터 냉방시스템 고효율화를 위한 국내 수열에너지 보급 제도 개선에 관한 연구)

  • Cho, Yong;Choi, Jong Min
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.17 no.3
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    • pp.21-29
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    • 2021
  • In this study, the current regulation of the water source energy, one of the renewable energy, was analyzed, and the improvement plan for the high efficient data center cooling system was suggested. In the improvement plan, the design and construction guidelines of the water source energy system permit to adopt the cooling and heating system with or without heat pump. In addition, it should also include the system operated in the cooling mode only all year-round. The domestic test standards to consider the water source operating conditions should be developed. Especially, it is highly recommended that the test standards to include the system with forced cooling and free cooling modes related with the enhanced data center cooling system adopting the water source energy.

The Heat Pump Application to the Food Concentration (열 펌프의 식품 농축에의 이용 연구)

  • Park, Noh-Hyun;Kim, Byeong-Sam;Kang, Tong-Sam;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.19 no.6
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    • pp.486-491
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    • 1987
  • The performance and applicability to food concentration of heat pump were investigated. During heating the water of spa from $43^{\circ}C$ to $51^{\circ}C$, COP's of heat pump (R-12, 150 HP) were 4.03 at heating part and 3.5 at cooling part. And, the efficiency of compressor (${\alpha}$) was 0.477 While the city water was heated to $39^{\circ}C$ by heat pump (R-22, 10 HP), its COP's were 3.0 at heating part and 1.87 at cooling part. During concentrations sucrose solution by centrifugal evaporator (ALFA-LAVAL CO, CTIB) with heat pump, heat capacity for condensating water vapor was required greater 15% than the latent heat for concentrating and then the overall heat transfer coefficient was $1196\;Kcal/m^{2}.\;h.\;^{\circ}C$. When low temperature concentration ($30-35^{\circ}C$, 28-40 Torr) of garlic extract was carried out by the water of $60^{\circ}C$ and $15^{\circ}C$ adjusted by heat pump, the ratio of heat capacity for concentrating vs. that for condensating of water vapor was 0.961.

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The Effect of Load Variation on the Performance of an Injection Heat Pump with an Economizer (이코너마이저 적용 열펌프 시스템의 부하변화에 따른 성능 특성 연구)

  • Choi, Jong Min;Park, Yong-Jung;Kang, Shin-Hyung
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.10 no.3
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    • pp.1-7
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    • 2014
  • Heat pumps have received a fair amount of attention all over the world for their high efficiency and low environmental impact. Employing heat pumps for residential heating and cooling produces only about 2038 kg-$CO_2$/year, an amount which is less than half that of conventional boiler systems. However, the use of single-stage heat pumps becomes uneconomical when they are operated at very low evaporating temperature or high condensing temperature. Two-stage heat pumps systems can be used successfully for low or high temperature applications. In this paper, the experimental study on the performance of two-stage heat pump with an economizer was executed in heating mode. When the secondary fluid inlet temperature to the indoor heat exchanger increased, the COP enhancement rate of two-stage heat pump with an economizer was increased. For all outdoor inlet temperature conditions, the performance of the heat pump with an economizer was higher than it without an economizer.

Performance Characteristics of a Vapor Injection Heat Pump System with Different Sub-cooler Capacity (과냉각 열교환기 용량 변화에 따른 인젝션 히트펌프의 성능 특성)

  • Choi, Jong Min;Park, Yong-Jung;Kang, Shin-Hyung
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.10 no.3
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    • pp.17-23
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    • 2014
  • One major breakthrough in the field of heating, ventilation and air conditioning has been the development of heat pumps. Heat pump systems offer economic alternatives for recovering heat from different sources for use in various industrial, commercial and residential applications. In recent years, the heat pump has been tipped to have a very good potential for hot water production. This paper investigated the performance of a vapor injection heat pump with the variation of sub-cooler capacity at heating mode. The heating capacity of the vapor injection heat pump slightly increased with an increment of sub-cooler capacity, while COP didn't increase continuously. The 20% capacity of sub-cooler comparing with system capacity could be used as a standard to select sub-cooler capacity.

Feasibility Study on Thermal Power Plant Condenser Heat Recovery for District Heating and Fuel Line Preheating (발전소 복수기 배열회수의 지역난방 및 연료라인 예열용 활용타당성 검토)

  • Jung, Hoon;Hwang, Gwang-Won
    • New & Renewable Energy
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    • v.5 no.3
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    • pp.40-48
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    • 2009
  • Recovered heat has been considered as a renewable energy in Europe since 2008 because its great effect on energy saving and carbon decreasing in plant process. Energy saving and decreasing green gas are critical issue today, so various technologies to save energy and decrease carbon dioxide in plant process have been applied to many industrial area. In this paper, the feasibility of condenser heat recovery by heat pump in power plant for district heating and fuel line preheating were reviewed by verifying energy (heat) balance and mass balance of power plant model. Some ways to compose proper system to recover heat of condenser are suggested and their possibilities are also reviewed. Limitations on heat recovery in power plant are also reviewed. The results are verified by calculating input/output energy based on actual performance test data of Taean Thermal Power Plant in Korea. There is noticeable improvement of plant performance in some cases which demand low temperature (<100 C) heat like distrcit heating, fuel line heating, and so forth.

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