• Title/Summary/Keyword: Heat pump system

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Research on the heating performance of SCW heat pump system for residential house (주거용 건물의 지하수 이용 지열 히트펌프 시스템의 난방성능 특성에 관한 연구)

  • Kim, Ju-Hwa;Kim, Ju-Young;Hong, Won-Hwa;Ahn, Chang-Hwan
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2008.04a
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    • pp.431-435
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    • 2008
  • Geothermal heat pump system using standing column wells as their ground heat exchanger can be used as a highly efficient source of heating and cooling in massive buildings. But there is no case of a small scale residential house. So this study estimated heating coefficient of performance(COP) of geothermal heat pump system using standing column well type which is excellent in heat recovery in the residential house. As a result of analysis, The COP of heat pump is over average 6 and is excellent. And in consequence of making a comparative study according to the bleeding, the cop is higher in the case of bleeding. Therefore, bleeding affects the performance of the system. This study has shown performance result that stands on actual data. Therefore, this study provides ground data that needs when a low capacity of system designs for a residence with confidence elevation.

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A Study on Improving the Efficiency of Ground Heat Exchanger (지중열교환기 성능 향상에 관한 연구)

  • Kim, Ook-Joong;Lee, Kong-Hoon;Kim, Min-Su
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.3142-3147
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    • 2008
  • A simple transient simulation of ground source heat pump system was carried out to investigate the effects of ground thermal conductivity on its performance. The TRNSYS code with a simple water to water heat pump model was used to compare the COP variation of the system. A new ground heat exchanger called by semi-closed loop was proposed and constructed in the real site. The effective thermal conductivity was measured using the test equipment developed by according to the line source model. The simulation results showed that highly efficient thermal conductivity of the grout material could increase the performance of the heat pump system very well. And the new ground heat exchanger showed the increased effective thermal conductivity as the penetration water flow rate(PWFR) was increased. Therefore, the performance improvement of the heat pump system using the proposed ground heat exchanger can be expected.

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Study on the Fuzzy Control of CO2 Heat Pump System (이산화탄소 열펌프 시스템의 퍼지 제어에 관한 연구)

  • Lee, Jae-Seung;Han, Yung-Hee;Kim, Min-Soo
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.513-518
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    • 2008
  • In the air-conditioning and refrigeration industry, the efforts to protect the environment have been made. One of them is to use carbon dioxide as an alternative refrigerant, however, several researches have shown that the transcritical heat pump system using $CO_2$ has relatively lower efficiency resulting in a degraded steady-state system performance. Capacity control with fuzzy controller was carried out for $CO_2$ heat pump system. Evaporator secondary fluid outlet temperature was suggested for the control variable of compressor speed modulation.

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Simulation of the Second Kind LiBr - H2O Absorption Heat Pump (2종 LiBr - H2O 흡수식 열펌프의 시뮬레이션)

  • Huh, J.Y.;Choi, Y.D.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.1 no.2
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    • pp.146-161
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    • 1989
  • The second 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 is affected considerably by the operating conditions of heat pump system, on the other hand, COP is little affected by them.

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Performance Characteristics of R134a Supercritical Heat Pump (R134a 냉매용 초임계 히트펌프의 성능 특성)

  • Choi, In-Soo
    • Journal of Power System Engineering
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    • v.18 no.4
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    • pp.60-65
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    • 2014
  • In this paper, cycle performance analysis for heating capacity, compression work and COP of R134a supercritical heat pump is presented to offer the basic design data for the operating parameters of the system. The operating parameters considered in this study include superheating degree, pressure and outlet temperature of gas cooler, compressor efficiency and evaporating temperature in the R134a supercritical heat pump system. The main results were summarized as follows : Superheating degree, pressure and outlet temperature of gas cooler, compressor efficiency and evaporating temperature of R134a heat pump system have an effect on the heating capacity, compression work and COP of this system. With a thorough grasp of these effect, it is necessary to design the supercritical heat pump using R134a. The prediction for COP of R134a supercritical heat pump have been proposed through multiple regression analysis.

An Experimental Study on Performance of Heat Pump System Using Hydrocarbon Refrigerants by Changing Indoor Load (실내 부하 변동에 따른 탄화수소계 냉매를 이용한 히트펌프 성능에 관한 실험적 연구)

  • Kim, Jae-Dol;Seong, Gwang-Hoon;Jeong, Seok-Kwon;Yoon, Jung-In;Lee, Ho-Saeng
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.2
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    • pp.204-210
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    • 2006
  • This study presents heat pump system characteristics using hydrocarbon refrigerants as alternative refrigerant for R-22 with respect to the variation of indoor load. Pure R-22 and R-290. R-600a, R-1270 were considered as working fluids The experimental apparatus was constructed to investigate the performance of heat pump using the air as a heat source. The performance were calculated based on compression shaft work. refrigeration capacity. pressure ratio, discharge temperature and COP. The experimental results show that the COP and refrigeration capacity of hydrocarbon refrigerants were higher than that of R-22. Through the above. hydrocarbon refrigerants are good alternatives in the heat pump system for R-22.

Study on the characteristic of heat exchange for vertical geothermal system using the numerical simulation (수치 시뮬레이션을 이용한 수직밀폐형 지열시스템의 채열특성에 관한 연구)

  • Nam, Yu-Jin;Oh, Jin-Hwan
    • Journal of the Korean Solar Energy Society
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    • v.34 no.2
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    • pp.66-72
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    • 2014
  • Ground source heat pump system can achieve high efficiency of performance by utilizing annually constant underground temperature to provide heat source for space heating and cooling. Generally, the depth of constant-temperature zone under the ground depends on surface heat flux and soil properties. The deeper the ground heat exchanger is installed, the higher the heat exchange rate can be acquired. However, in order to optimally design the system, it is necessary to consider both the installation cost and the system performance. In this study, performance analysis of ground source heat pump system according to the depth has been conducted through the case study.

Performance Analysis of a Heat Pump Using Refrigerant Mixtures (II) (혼합냉매를 사용한 열펌프의 성능해석 (II))

  • Kim, M.S.;Kim, T.S.;Won, S.P.;Ro, S.T.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.2 no.3
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    • pp.218-225
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    • 1990
  • Studies on the performance of a heat pump using non-azeotropic refrigerant mixtures are done. In order to estimate the thermodynamic properties for the selected non-azeotropic refrigerant mixtures including R22/R152a, R22/R142b, R22/R114 and R13B1/R152a, Peng-Robinson equation of state is adopted. The pressure-enthalpy diagram and the temperature-entropy diagram are plotted for each refrigerant mixture. Considerations on the capacity modulation for the heat pump system using refrigerant mixtures are taken into. Results show that when the heating load varies, the possibility for the capacity modulation is found in the heat pump system using a compressor with constant volume flow rate. Under a constant heating capacity condition in the heat pump system, the coefficient of performance increases when the refrigerant mixtures are used. The volume flow rate decreases as the mass fraction of lower boiler increases in this case.

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Performance Analysis and Prior-Treatment of Heat Pump System with Low-Temperature Water Heat Source (저온수열원이용 열펌프시스템의 전처리 및 성능분석)

  • Park, Seong-Ryong;Chang, Ki-Chang;Lee, Sang-Nam;Ra, Ho-Sang;Park, Jun-Tack
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.258-263
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    • 2000
  • River water is higher in temperature than the surrounding environment during the winter. It is highly suitable a heat source for heat pump system. Despite its suitability, however, it is not widely used, due to its fouling and corrosive nature in heat exchanger tubes of evaporator. It is designed prior-treatment system which come into direct contact with the river water, such as auto-seamer, ozone generator for bactericidal test and auto-cleaning system. And it is analyzed treatment effects for its operation. It is designed two-stage compression heat pump system using R-134a with heating load 35.16kW, ad analyzed its performance. As a result it is obtained 3.08 COP when mid-point pressure is 1,200kPa, and bypass ratio of flowing refreigerant to high-stage compressor is 25.1%

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Temperature monitoring and seasonal borehole heat exchange rate characteristics of a geothermal heat pump system (지열 히트펌프 시스템의 계절별 지중 열교환 특성 및 지반내 온도 변화)

  • Shim, Byoung-Ohan
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.452-455
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    • 2007
  • The geothermal heat pump system is designed for cooling and heating for three stories building (2,435 $m^2$) includes total 79 heat pumps. Therefore, the monitoring system is installed for each floor and the data is automatically transmitted to the monitoring system. Heat exchange rate and temperature of a geothermal heat pump system have been monitored for a long period. The seasonal operation of geothermal heat pump shows the different shape of heat exchange rate for cooling and heating. Ground water flow can influence on heat exchange rate and thermal storage of the system. In order to define the hydraulic characteristics and groundwater temperature variation, the relationships among air temperatures, groundwater temperatures, water table, and precipitation are analysed.

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