• Title/Summary/Keyword: Heat pump system

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Analytical Study on the Performance of Ground Source Compound Hybrid Heat Pump System for Large Community Building (대형 Community 건물의 지열원 복합 하이브리드 히트펌프 시스템 성능에 관한 해석적 연구)

  • Byun, Jae-Ki;Jeong, Dong-Hwa;Lee, Jong-Gil;Hong, Seong-Ho;Choi, Young-Don;Cho, Sung-Hwan
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.05a
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    • pp.634-637
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    • 2008
  • Ground source heat pumps are clean, energy-efficient and environment-friendly systems cooling and heating. Although the initial cost of ground source heat pump system is higher than that of air source heat pump, it is now widely accepted as an economical system since the installation cost can be returned within an short period of time due to its high efficiency. In the present study, performances of ground source compound hybrid heat pump system applied to a large community building are simulated. The system design and operation process appropriate for the surrounding circumstance guarantee the high benefit of the heat pump system applied to a large community building. If among several renewable energy sources, ground, river, sea, waste water source are chosen as available alternative energies are combined, COP of the system can be increased largely and hybrid heat pump system can reduced the fuel cost.

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A Study on the Greenhouse Heating Performance of Heat Pump System (온실난방을 위한 히트펌프의 성능에 관한 연구)

  • 윤용철;서원명;이석건
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.40 no.3
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    • pp.94-102
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    • 1998
  • This experiment was carried out to study on the effect of greenhouse heating by water-to-water heat pump system employing heating water tank(ground water) as the heat source. Followings are the results obtained from this study ; 1. The heat amount absorbed from evaporator and the heat amount rejected from condenser were approximately 9, 000~ 12, 000kcal/h and 13, 000~ 17, OOOkcal/h, respectively. 2. The heat efficiencies of evaporator and condenser used in this experiment were approximately 79% and 83%, respectively. 3. The maximum heating load estimated for the experimental greenhouse was about 18, 000 ~ 25, OOOkcal/h, which was found to be about 28 ~ 32% higher than the heating capacity of the heat pump system adopted for this experiment. 4. The coefficients of performance(COP) for the heat pump and the total heat pump system were approximately 2.9~3.5 and 1.5~2.4, respectively. 5. The coefficient of performance(COP) calculated from the Mollier Diagram was about 3.2 ~ 3.4, which was reasonably close to the COP estimated on the basis of measured values. 6. The temperature of experimental greenhouse heated by the heat pump system could be maintained about 12~15 。C higher than that of a control greenhouse.

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A Characteristics Simulation of Heat Pump System for Sewage Water as a Heat Source (하수열원 열펌프 시스템의 성능 시뮬레이션)

  • Park, Il-Hwan;Chang, Ki-Chang;Lee, Young-Soo;Yoon, Hyung-Kee;Baek, Young-Jeen
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.4
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    • pp.280-286
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    • 2008
  • In this study, characteristics simulation of heat pump system is investigated for heating and cooling using sewage water as a heat source. A simulation program for preestimate operation characteristics of heat pump system is developed. The performance of this system is resolved by several variables and the characteristics which is based on actual air and sewage temperature data. The simulation results agree well with the experimental values of COP. In the analysis of system characteristics, the COP is changed between $3\sim5$ in winter season for heating load, $4\sim6$ in summer season for cooling load. As the results of Life Cycle Cost analysis over a 15 year life cycle, the energy cost could be reduced by 250 million won if a heat pump system was used instead of a conventional boiler and an absorbtion refrigerator on the office building.

A Study on the Performance Improvement of a Simultaneous Heating and Cooling Water Source Heat Pump System by Controlling of the Refrigerant Flow Rate in an Outdoor Unit (수열원 냉난방 동시형 히트펌프 시스템의 실외 열교환기 유량제어를 통한 성능개선에 관한 연구)

  • Bae, Heung Hee;Lee, Dong Hyuk;Lee, Sanghun;Kim, Byengsoon;Ahn, Young Chull
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.3
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    • pp.131-136
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    • 2013
  • The present study has conducted cycle design and control technology of a water source VRF heat pump system. Previously, study of a simultaneous heating and cooling in an air source VRF heat pump system has been conducted. However, performance data and design methods for simultaneous heating and cooling in a water source VRF heat pump system are limited in the literature, due to various system parameters and operating conditions. In this study, the operating characteristics and performances of a simultaneous heating and cooling heat pump system are carried out, in simultaneous operation modes. Control logics of an EEV are developed for flow rate control to the outdoor unit, and are verified. When the control logics are applied, the simultaneous cooling and heating performances are sufficiently achieved, and system COPs are increased by up to 23.4%.

Simulation of the First Kind LiBr-H2O Absorption Heat Pump (제1종 LiBr-H2O 흡수식 열펌프의 시뮬레이션)

  • Huh, J.Y.;Choi, Y.D.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.2 no.1
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    • pp.11-26
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    • 1990
  • The first kind LiBr -$H_2O$ absorption heat pump system was simulated and the performances of it were predicted. The elements of heat pump system, evaporator, absorber and generator were analysed by solving the energy balance equations and concentration equations which describe the reactions between working fluids. The results show that the temperature gain of absorber and condenser and the COP of the system are affected considerably by the operating conditions of heat pump system.

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Fuzzy Defrost Control of the Multi-Type Heat Pump System (퍼지룰을 이용한 멀티형 히트펌프 시스템의 제상 제어)

  • 한도영;김경훈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.8
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    • pp.711-716
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    • 2000
  • A fuzzy defrost control algorithm for the multi-type heat pump system was developed. In the fuzzy defrost control algorithm, the air temperature difference at the outdoor unit and the refrigerant pressure difference at the compressor were used as input variables, and the defrost starting time and the defrost time interval were used as output variables. This fuzzy algorithm was applied to the multi-type heat pump system and tested in the five dynamic environmental chambers. Test results show that the newly developed control algorithm is more effective than the conventional control algorithm in the removal of frost formed at the outdoor unit of the heat pump.

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Study on the Optimum Design of a Heat Pump System Using Solar and Ground Heat (태양열 및 지중열원을 이용한 히트펌프 시스템의 최적이용법에 관한 연구)

  • Nam, Yu-Jin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.6
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    • pp.509-514
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    • 2012
  • In this research, a heat pump system with a heat source network is suggested which utilizes solar heat and ground heat as heat source for cooling and heating. This paper describes the summary of the suggested system and the results of the annual energy simulation. The heating and cooling loads, the electric consumption and the COP were calculated by TRNSYS 16 and evaluated in the cases of different local conditions and different system compositions. In the results, the superiority of the suggested system has been quantitatively evaluated comparing with the conventional heat pump system using one heat source. Furthermore, it was more significant in cold climate, in which the heating COP was 146% increased compared the air source heat pump system, than it in subtropical climate, 119% increased.

LCC Analysis of a Heat Pump System Using River Water (하천수 열원 이용 열펌프 시스템의 LCC 분석)

  • Han, Sang-Soo;Park, Cha-Sik;Kim, Yong-Chan
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.1424-1428
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    • 2009
  • The performance of a heat pump using river water as a heat source was compared with that of a conventional air-conditioner for cooling and a boiler system for heating. The heat pump system using river water considered the 1-stage cycle for cooling and the 2-stage cycle for heating. The COPs of the river water source heat pump were $0.5{\sim}1.1$ higher than those of the conventional system in the cooling season. The LCC of the river water source heat pump system was lower 13.5% and 32.4% than that of the conventional system I and II. In addition, when the initial cost ratios of the river water source heat pump system to the conventional system I and II were less than 1.2 and 1.4, respectively, an acceptable payback was found to be less than 5 years.

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Simulation Program Verification and Performance Prediction of the Multi-type Heat Pump System

  • Han, Do-Young;Park, Kwan-Jun;Lee, Han-Hong
    • International Journal of Air-Conditioning and Refrigeration
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    • v.9 no.4
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    • pp.47-54
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    • 2001
  • The simulation program which can predict major performances of the multi-type heat pump system was developed. In order to verify the simulation program, several experimental tests were performed under various recommended conditions. The experimental results show in good agreement with simulation results. The verified simulation program was used to analyze the system performance. The capacities and the COP's under the various indoor and outdoor conditions were predicted. Therefore, it may be concluded that the system simulation program developed in this study may be effectively used for the system design and the performance prediction of the multi-type heat pump system.

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The Performance Characteristics of Heat Pump Using the Refrigerant Subcooling (냉매 과냉각을 이용한 열펌프 시스템의 성능 특성)

  • Roh, Geon-Sang;Son, Chan-Ghyo
    • Transactions of the Korean hydrogen and new energy society
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    • v.18 no.4
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    • pp.413-421
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    • 2007
  • In this paper, the performance characteristics of heat pump system using a new refrigerant subcooling system designed for the study, are introduced. The new heat pump system have the ice storage tank at the outlet of condenser. The experimental apparatus is a well-instrumented water/water heat pump which consisted of working fluid loop, coolant loop, and ice storage tank. The experiment parameters of subcooling ranged as the evaporating temperature from $-5^{\circ}C$ to $8^{\circ}C$, the condensing temperature from $30^{\circ}C$ to $35^{\circ}C$. The test of the ice storage was carried out at evaporating temperature of $-10^{\circ}C$ and the ice storage mode is Ice-On-Coil type. The working fluid was R-22 and the storage materials were city-water. The test results obtained were as follows; The refrigerant mass flow rate and compressor shaft power were unchanged by the degrees of subcooling, that is, they were independent of degrees of subcooling. The cooling capacity of the new heat pump system increase as the evaporating temperature and subcooling degrees increase and is higher by $25{\sim}30%$, compared to the normal heat pump system. The COP of the new heat pump system increases as the degrees of subcooling and evaporating temperature increase and is higher by 28% than that of the normal heat pump system.