• 제목/요약/키워드: Cooling capacity

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An Experimental Study on the Measurement Error in the Performance Testing of Air Conditioners Using a Psychrometric Calorimeter (건습구식 칼로리미터를 이용한 공기조화기 성능측정상의 계측오차에 대한 실험적 연구)

  • 김봉훈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.5
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    • pp.415-423
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    • 2002
  • An experimental study using a psychrometric calorimeter was conducted to investigate the temperature and pressure mea surement errors permitted for determining cooling capacity of an air conditioner. First, the instrument calibration was made in accordance with the related test methods and guidelines in order to accurately evaluate basic performance (cooling capacity and airs flow rate). Secondly, a parametric study was performed to examine the effect of measurement error involved if temperature and pressure measuring instruments on the cooling capacity calculation. From the results, it was found that the degree of accuracy for both temperature and pressure measurements played an important role on the error occurring in the determination of cooling capacity and needed to be maintained within a certain value to guarantee required accuracy of cooling capacity.

An Experiment for Estimating the Cooling Capacity of the Radiant Ceiling Panel System (천장 복사 패널시스템의 방냉량 평가 실험)

  • Park, Sang-Hoon;Kim, Dong-Woo;Yeo, Myoung-Souk;Kim, Kwang-Woo
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.30 no.2
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    • pp.267-276
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    • 2014
  • The radiant ceiling panel system (RCPS) is a light-weight type of radiant heating and cooling system which uses a ceiling as a radiant surface. To obtain improved thermal comfort and maintain the room temperature comfortably, it is important to estimating the cooling capacity of the RCPS. The purpose of this study is to presents an experimental methodology to estimate the cooling performance of the RCPS. This paper also presents an estimation result of the cooling capacity of the RCPS using the experimental methodology. The previous standards about method for estimating cooling capacity of the RCPS are analyzed. The experimental methodology is evaluated based on the concept of the cooling capacity and its boundary condition during the experiment. The experimental methodology is set as a Test Cell while applying the experimental method. A test cell composed of the heat source, the distribution system. Using the test cell, the thermal performance of a radiant ceiling panel system is estimated. The experimental results are validated numerically in order to verify the accuracy. The test result shows the nominal capacity of the RCPS.

Experimental Study on Cooling Characteristics of Multi - Air Conditioner using Inverter Scroll Compressor (인버터 스크롤 압축기를 사용한 멀티 에어컨의 냉방 특성에 대한 실험적 연구)

  • 권영철;고국원;진의선;허삼행;전용호;이영덕;박인규
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.4
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    • pp.311-317
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    • 2004
  • In the present study, the cooling characteristics of the multi-air conditioner (A/C) using an inverter scroll compressor are experimentally investigated for the number of the indoor units and the operating conditions (2$0^{\circ}C$, 24$^{\circ}C$, 26$^{\circ}C$) under the cooling standard conditions by KS C 9306. In the case of the simultaneous operation for 3 indoor units, the cooling capacity, the mass flow rate and the input power have a decreasing trend and COP has an increasing trend, with decreasing the difference in the operating temperature of the indoor unit and the room temperature. In the case of the simultaneous operation for 2 indoor units, the COP of the indoor unit with large cooling capacity is high when the operating temperature is high, but the COP of the indoor unit with low cooling capacity is high when the operating temperature is low. In the case of the single operation for one unit, when the large cooling capacity of the indoor unit is less than 50% the compressor operates at the minimum operation frequency region and the COP decreases.

An Experimental Study of a Therr Buffer Pulse Tube Refrigerator (Three Buffer 맥동관 냉동기에 관한 실험적 연구)

  • 박성재;고득용;김효봉;신완순
    • Progress in Superconductivity and Cryogenics
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    • v.1 no.2
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    • pp.54-59
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    • 1999
  • An experimental study was carried out to improve the cooling capacity and performance of the pulse tube refrigerator. Three buffer pulse tube refrigerator was designed and fabricated, and the experimental apparatus operating process of the therr buffer pulse tube refrigerator and results obtained with the performance test. The cooldown characteristics and load characteristics are described. The lowest temperature measured in the three buffer pulse tube refrigerator was 88K and the cooling capacity at the optimum operating condition was 27 W at 120K.

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A Study on the Heat Transfer Characteristics of the Radiant Chilled Ceiling Panel for Space Cooling (냉각된 복사천장패널의 열전달 특성에 관한 연구)

  • Lee, Tae-Won;Hwang, In-Ju
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.164-169
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    • 2001
  • There is a chilled ceiling panel which carries out the air conditioning by radiation and convection between the room and cold ceiling panel surface. In order to verify heat transfer characteristics between them in cooling system with radiant chilled ceiling panel, analytical and experimental studies were performed for various design and operating parameters such as tube space and diameter, inlet water temperature, mass flow rate, cooling load, and so on. In this study, we found that the tube space and inlet water temperature were more important elements than the tube diameter and water flow rate for the performance of radiant chilled ceiling panel. The cooling capacity of the radiant chilled ceiling panel had the maximum value of $65W/m^{2}$ because the highest cooling capacity was limited by the condensation on the panel surface. The results of comparison between numerical analysis and experiment showed a resonable agreement qualitatively, especially for low cooling capacity.

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Basic Design and Performance Analysis of an Solar Absorption Chiller (태양열 구동 흡수식 냉동기의 기본설계 및 성능분석)

  • Baek, N.C.;Yoon, E.S.;Joo, M.C.;Jeong, S.
    • Solar Energy
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    • v.18 no.3
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    • pp.107-112
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    • 1998
  • Basic design of a solar driven absorption cooling machine(SDACM) with a cooling capacity of 5 USRT was carried out. The SDACM is a single effect cycle driven by low temperature hot water from solar collectors. The SDACM design data were calculated by the steady state simulation program which was developed in this study The variation of COP and cooling capacity of the SDACM were investigated at different off-design conditions. Both the cooling capacity and the system COP were improved with decreasing cooling water temperature. If hot water temperature was increased, the cooling capacity was improved but the system COP was found to be decreased. The decrease of the system COP were basically caused by increased thermal loads in the system components.

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An Effect on the Solution Crystallization Temperature Difference and Cooling Capacity of the Absorption Chiller by a Solution Cooler in the Absorber (흡수기내 용액 냉각기가 흡수식 냉동기의 용액 결정화 온도차와 냉각 용량에 미치는 효과)

  • Chin, Sung-Min;Lee, Jae-Heon;Jurng, Jong-Soo
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1518-1523
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    • 2003
  • The objective of the present work is to investigate an effect on the solution crystallization temperature difference and the cooling capacity of the absorption chiller by a solution cooler in the absorber. The cooling capacity of the absorption chiller can be higher, with the enhanced performance of the solution heat exchangers. But, because the solution crystallization temperature difference becomes smaller at the absorber inlet, the heat capacity of the solution heat exchangers might be limited by the danger of crystallization, which can cause the serious damages. In this paper, the heat capacity ratio of the solution cooler is defined as the ratio of the heat capacity of the solution cooler to that of the absorber. If it becomes larger in the additional type solution cooler, the solution crystallization temperature difference is augmented and the cooling capacity is also increased.

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Effects of performance analysis of a desiccant cooling system with a direct evaporative cooler in the regeneration process (재생 입구 직접증발냉각기 적용이 제습냉방시스템 성능에 미치는 영향)

  • Dash, Ulziiutas;Oh, Myung-Do
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.633-638
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    • 2009
  • In this study the performance analysis and cooling capacity of desiccant cooling system incorporating regenerative cooler and direct evaporative cooler in the regeneration air inlet were investigated on the condition of low regeneration temperature and time rotation 180s and area ratio of regeneration to dehumidification section 0.7. The cooling capacity and COP are evaluated at various effectiveness values of the direct evaporative cooler or the regenerative evaporative cooler. As either of effectiveness of the regenerative and direct evaporative coolers of desiccant cooling system increases, both the cooling capacity and COP increase, but effectiveness value of regenerative cooler gives the opposite effect on the system performance. It is found that effectiveness of regenerative cooler less than 0.7 shows the optimum cooling capacity.

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Performance and Heat Transfer Characteristics of Heat Pump System Using Refrigerant Mixtures (혼합냉매를 사용한 열펌프 시스템의 성능과 열전달 특성)

  • Kim, T.S.;Shin, J.Y.;Ro, S.T.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.4 no.4
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    • pp.360-369
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    • 1992
  • A heat pump system is constructed to evaluate its performance and heat transfer characteristics with mixtures of R22/R142b as working fluids. The heat transfer in the evaporator and the overall performance are measured and analyzed in terms of the compositions and relevant variables. Possibility of capacity modulation by changing composition is observed without degradation of heat transfer coefficients and coefficient of performance. The cooling capacity is varied continuously within 200 percent based on minimum capacity at constant compressor speed. For similar cooling capacity, COP is improved by mixing two refrigerants and shows maximum value at 60% mass fraction of R22. Average heat transfer coefficients of mixtures decrease in comparison with pure refrigerants at similar cooling capacity and mass flow rate. However, the overall heat transfer coefficients decrease moderately. A cycle simulation is performed in order to manifest the advantages of using refrigerant mixtures, considering experimentally observed heat transfer characteristics.

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An Experimental Study of Adsorption Chiller using Silica gel-Water (실리카겔-물계 흡착식 냉동기에 관한 실험적 연구)

  • Kwon, Oh-Kyung;Yun, Jae-Ho;Kim, Joung-Ha
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.1119-1124
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    • 2006
  • The objectives of this paper are to investigate the performance of silica gel-water adsorption refrigeration system with heat recovery process from the system experiment. This system can be driven by waste heat at near ambient temperature from $60^{\circ}C$ to $90^{\circ}C$. The cooling capacity and coefficient of performance(COP) were measured from various experimental conditions. An experimental results revealed the influence of operating temperatures(hot, cooling and chilled water), water flow rates, and adsorption-desorption cycle times on cooling capacity and COP. Under the standard conditions of $80^{\circ}C$ hot water, $25^{\circ}C$ cooling water, $14^{\circ}C$ chilled water inlet temperatures and 420sec cycle time, a cooling capacity of 1.14kW and a COP for cooling of 0.55 can be achieved.

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