• Title/Summary/Keyword: Heat pump

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Cooling Performance Measurement of a 3 Room Type Inverter Heat Pump System (3실형 인버터 열펌프 시스템의 냉방성능 측정)

  • 정광진;최영돈;장효환;송재복;박윤철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.6
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    • pp.431-439
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    • 2001
  • Recently, multi-room type heat pump system has aroused much attention, because it can achieve much reduction of installation cost and space as well as energy saving in companion with the single room type heat pump system. In the present study, performance characteristics of a 3 room type inverter driven heat pump system, which is widely spread in Japanese market, are measured.. In the single room operation, performances of a heat pump system such s the difference of compressor outlet and inlet pressures and the mass flowrate may increase with the increase of cooling capacity so that COP of the system decrease with the increase of cooling capacity. However, in the 2 room operation, mass flowrate and COP of the total system increase markedly as compared with the single room operation.

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A Study on Performance Analysis of the Bubble Pump in Solar Water Heater System (태양열 온수기 시스템에 적용된 기포펌프의 성능평가에 대한 연구)

  • Lee, Kwang-Sung;Li, Xuesong;Jin, Zhenhua;Jeong, Hyo-Min;Chung, Han-Shik
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2310-2315
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    • 2008
  • In this paper, study on performance analysis of bubble pump on the domestic solar water heater system is presented. Device of this experiment is consisted of bubble pump, solar collector and heat exchanger. At the mean time, this system have attached temperature sensors and pressure sensors at bubble pump. In addition, the flow meter was installed at outlet of heat exchanger. And then result of experimental study, average value of the heat exchange amount in heat exchanger was about 7.9kcal/hr, the maximum value of the heat amount in water tank($0.4m^3$) was 489.7kcal/hr and the maximum value of the mass flow rate in bubble pump was about $0.5{\ell}/min$.

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Analysis on Economic Feasibility of Electric Night Storage Heat Pump as a Substitution of a Heater (심야전기보일러 대체 Heat Pump의 경제성 분석)

  • JUNG, H.;JO, J.Y.;Lee, C.H.
    • Journal of the Korean Society of Mechanical Technology
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    • v.13 no.3
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    • pp.119-124
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    • 2011
  • Electric night storage heater was introduced and disseminated for power grid balancing and efficient management of power generation facility. But fuel cost for heating has been increased rapidly while the cost of electricity increased slightly. This abnormal rate system caused peak load in winter at last. To solve this problem, application of an air source heat pump was suggested. In the study, the effect of replacing night heater by heat pump and the economics were analysed. In addition the expectation of prospect of heat pump penetration was simulated based on surveyed and investigated data. As a result, fund supporting as well as institutional backing was needed for effective propagation and return of investment.

Performance Evaluation of a $CO_2$ Heat Pump System for Fuel Cell Vehicles (연료전지 자동차용 이산화탄소 열펌프 시스템의 성능평가)

  • Kim, Sung-Chul;Park, Jong-Chul;Kim, Min-Soo;Won, Jong-Phil
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.1
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    • pp.37-44
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    • 2008
  • The global warming potential (GWP) of $CO_2$ refrigerant is 1/1300 times lower than that of R134a. Furthermore, the size and weight of the automotive heat pump system can decrease because $CO_2$ operates at high pressure with significantly higher discharge temperature and larger temperature change. The presented $CO_2$ heat pump system was designed for both cooling and heating in fuel cell vehicles. In this study, the performance characteristics of the heat pump system were analyzed for heating, and results for performance were provided for operating conditions when using recovered heat from the stack coolant. The performance of the heat pump system with heater core was compared with that of the conventional heating system with heater core and that of the heat pump system without heater core, and thus the heat pump system with heater core showed the best performance among the selected heating systems. On the other hand, the heating performance of two different types of coolant/air heat pump systems with heater core was compared each other at various coolant inlet temperatures. Furthermore, to use exhausted thermal energy through the radiator, experiments were carried out by changing the arrangement of a radiator and an outdoor evaporator, and quantified the heating effectiveness.

Dynamic Modeling and Simulation of a Hybrid Heat Pump (하이브리드 열펌프 동적 모델링 및 시뮬레이션)

  • Shin, Younggy;Kim, Jae Hyun;Yoo, Byeong Jun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.7
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    • pp.406-412
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    • 2013
  • A hybrid heat pump is under development with the goal of utilizing 120% of primary energy resources. A plate heat exchanger is added between the compressor and air-cooled condenser of an ordinary heat pump to heat water. For successful operation of the heat pump, it is necessary to develop a control algorithm under various operating conditions. As a virtual test bed for that purpose, a dynamic model has been developed, to simulate its dynamic behavior. It was modeled in transient one-dimensions, with varying phase lengths considered. The model was implemented in Matlab and Simulink. Simulation results were effectively applied to design a control algorithm. They also provided physical insight into how to design and operate the system.

A Third-order Simulation Model of a Vuilleumier Cycle Heat Pump

  • Kang, Young-Goo;Jeong, Eun-Soo
    • International Journal of Air-Conditioning and Refrigeration
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    • v.6
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    • pp.80-92
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    • 1998
  • A third-order simulation model of a Vuilleumier{VM) heat pump has been developed. This model takes into account the major losses such as the heat conduction losses through regenerators and displacers, the pumping losses and the wall-to-gas heat transfer losses in active volumes, in addition to the heat exchanger and regenerator losses. The working volume was divided into 12 control volumes and the conservation equations of mass and energy were applied to each control volume. Pressure drops were considered in regenerators only. Thermodynamic behavior of the working gas in a VM heat pump was investigated and effects of the major losses and operating conditions on the performance of a VM heat pump were shown.

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Design and performance analysis of water-to-air heat pump system using double-tube heat exchanger (이중관 열교환기를 사용한 물 대 공기 열펌프 시스템의 설계와 성능해석)

  • Han, D.Y.;Park, K.J.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.4
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    • pp.462-471
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    • 1997
  • The water-to-air heat pump system requires relatively lower energy consumption and less installation space. The heat exchangers used for this system are the finned-tube type for the indoor unit and the double-tube type for the outdoor unit. Mathematical models for this system are developed and programmed in computer. Experimental data from various conditions are obtained and compared with calculated values from the computer simulation program. Differences of cooling capacity and COP are 1.25% and 0.47%, and those of heating capacity and COP are 0.51% and 0.13%, respectively. Simulation results are in good agreement with test results. Therefore, the developed program is effectively used for the design and the performance prediction of water-to-air heat pump system.

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A Study on Heating Characteristics of Ground Source Heat Pump with Variation of Heat Exchange Methods (열교환방식에 따른 지열히트펌프의 난방특성에 관한 연구)

  • Cha, Dong-An;Kwon, Oh-Kyung;Park, Cha-Sik
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.8 no.2
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    • pp.9-15
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    • 2012
  • The objective of this study is to investigate the influence on the heating performance for a water-to-water 10RT ground source heat pump by using the water switching and refrigerant switching method. The test of water-to-water ground source heat pump was measured by varying the compressor speed, load side inlet temperature, and ground heat source side temperature. The heating capacity and COP of the heat pump increased with increasing ground heat source temperature. As a result, compared to a refrigerant switching method, the water switching method with counter flow improves the heating capacity and COP by approximately 5% in average, respectively.

Verification experiment of a ground source multi-heat pump at cooling mode (지열원 시스템 히트펌프의 냉방 성능 특성에 관한 실증 연구)

  • Lim, Hyo-Jae;Kang, Shin-Hyung;Choi, Jae-Ho;Choi, Jong-Min;Moon, Je-Myung;Kwon, Young-Seok;Kwon, Hyung-Jin;Kim, Rock-Hee
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.21-26
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    • 2008
  • Recently, small and medium-sized buildings have employed a multi-heat pump. The major benefits of the multi-heat pump over a conventional system are that it is easier system to maintain along with a diversification of facility use, and high comfortability. The performance of multi-heat pump systems can be enhanced by using geothermal energy instead of air source energy. This paper describes the multi-heat pumps applied in an ground source heat pump system for an actual building. The performance of a ground source multi-heat pump installed in the field was investigated in cooling mode. The maximum COP of the systems with single U-tube and double tube ground loop heat exchangers were 6.6 and 6.0, respectively. It is suggested that the new algorithms to control the flow rate of secondary fluid for ground loop heat exchanger have to be developed in order to enhance the performance of the system.

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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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