• Title/Summary/Keyword: Heat pump

Search Result 1,218, Processing Time 0.089 seconds

Development of Heat Pump System for High Efficiency Engine Vehicle (고효율엔진 차량 히트펌프 시스템 개발)

  • Park, Byung-Duck;Won, Jong-Phil;Lee, Won-Suk
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.10 no.1
    • /
    • pp.21-26
    • /
    • 2007
  • As DDI or GDI engine discharges very low heat due to its high thermal efficiency, the heat source is not enough for heating the passenger compartment in cold climate condition. To remedy the heating problem, the conventional HFC-134a automotive air-conditioning system has been attempted to run as a heat pump mode. Futhermore, an auxiliary electric heater of new type was equipped to the heat pump air-conditioning loop as a new approach. Hence, a proto-type heat pump air conditioner has been made and tested to investigate the feasibility of the HFC-134a automobile air-conditioning system that could be worked as a heat pump. The experiment results showed that the sufficient heating capacity could be obtained by adding a heat pump with an new electric type auxiliary heater into the conventional heat core in low temperature condition.

  • PDF

Influence of Low Stage Refrigerant Charge Amount on the Performance of Cascade Heat Pump (캐스케이드 열펌프의 저단 사이클 충전량 변화에 따른 성능 특성)

  • Park, Seung Byung;Choi, Jong Min
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
    • /
    • v.11 no.1
    • /
    • pp.15-20
    • /
    • 2015
  • In this study, the optimization and performance characteristics of a cascade heat pump system was analyzed with the variation of low stage refrigerant charge amount. The cascade heat pump was designed and constructed with R134a and R410A as the refrigerant for high stage and low stage cycle, respectively. Experiments were conducted by varying the low stage charge amount and the performance characteristics of the cascade heat pump were studied. The refrigerant charge amount of the low stage cycle was varied between the ranges of -15% and +10% of the optimum charge amount. The performance variation experienced in the cascade heat pump due to the variation of refrigerant charge amount shows greater effect in the undercharge regions than the overcharge regions. COP reduction in the undercharge region is larger than the decrease in the overcharge region. Some cycle variation such as power consumption and cycle pressure according to low stage refrigerant charge amount showed different trends comparing with those according to high stage refrrgerant charge amount. Therefore, the optimum charge amount of the cascade heat pump should be determined based on the experimental data obtained by the variation of high and low stage refrigerant charge amount.

The Performance Test and the Feasibility Study for a Dual-Source Heat Pump System Using the Air and Ground Heat Source (공기 및 지열 이용 Dual-Source 히트펌프 시스템의 성능실험 및 경제성 분석)

  • Nam, Yujin;Chae, Ho-Byung
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.26 no.5
    • /
    • pp.212-217
    • /
    • 2014
  • Recently, the use of renewable energy has been increased due to growing concern on the energy-saving at buildings and the reduction of $CO_2$ emission. In the field of architecture, to reduce the energy consumption of heating, cooling and hot water supply, heat pump systems with renewable energy has been developed and used in various applications. However, there have been many of researches on the large-scale commercial heat pump systems, but the research and the field application of a compact heat pump system is rare. Therefore, in order to develop the compact heat pump for the small-scale residential building, this study conducted the performance test and feasibility study for a hybrid heat pump using the heat source of air, solar and ground. In the results of experiments through a trial product, the average COP of cooling mode with ground heat source was 4.75, and it of heating mode was 4.03. Furthermore, the average COP of cooling mode with air heat source was 2.60, and it of heating mode was 2.92. Finally, payback period of the system was calculated as 9.2 years.

Economic Analysis of Heat Pump System in Educational Building -Focused on the High School of Twenty Four Classes- (교육용 건축물의 히트펌프 냉난방시스템에 대한 경제성 분석 -24학급 규모의 고등학교를 중심으로-)

  • Park, Ryul;Park, Min-Yong;Kim, Jong-Min
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.15 no.10
    • /
    • pp.879-887
    • /
    • 2003
  • Buildings with heating and cooling systems have been increased, since the requirement of thermal comfort for residents is grown. Heating and cooling systems, have been changed from two separate systems to one multi-function system which includes both heating and cooling. Especially, heat pump heating and cooling system has been adopted for general classrooms in schools since education environment improvement project has been launched. This research suggests the best option for the heat pump heating and cooling system in educational buildings through economic assessments for four alternative systems based on electric heat pump (EHP) and gas engine driven heat pump (GHP), which are most widely used for elementary, middle and high schools. The model buildings are in the Y high school which has 24 classes of new construction building, which will be built soon. Annual energy consumption for alternative systems uses BECS 3.10, which can be used for system simulation.

Heating Performance Evaluation of the VRF Heat Pump System with Refrigerant Heating Cycle for the Extreme Cold Region (냉매 가열식 대용량 VRF 히트펌프 사이클 설계를 통한 극한랭지 난방 성능 평가)

  • Lee, Sang-Hun;Choi, Song;Kim, Byeng-Soon;Lee, Jae-Keun;Lee, Kang-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.23 no.8
    • /
    • pp.571-579
    • /
    • 2011
  • Heat pump systems for commercial building with variable refrigerant flow(VRF) are expanding a market due to high energy efficiency, lower maintenance cost and easy installation comparing with the conventional heat pump with the constant refrigerant flow. In general, heat pump systems degrade the energy efficiency in the extremely low temperature regions. In this study, VRF heat pump system with refrigerant heating is experimentally investigated to overcome the low heating performance in the extremely low temperature regions. VRF heat pump system with refrigerant heating is found out the sufficient heating performance in the -25 degree temperature condition comparing with the conventional heat pump system and is obtained more than 2,500 kPa high pressure in the evaporator at low temperature.

Experimental Study on the Heating Performance Improvement of R134a Heat Pump System for Zero Emission Vehicles (무공해자동차용 R134a 히트펌프 시스템의 난방성능 향상에 관한 실험적 연구)

  • Lee, Dae-Woong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.26 no.6
    • /
    • pp.257-262
    • /
    • 2014
  • This paper describes an experimental study for heating performance that can be used in R-134a automobile heat pump systems. The heat pump system is widely studied for heating system in zero-emission vehicles to attain both the small power consumption and the effective heating of the cabin. This paper presents the experimental results of the influence on heating capacity and coefficient of performance of heat pump system. Tests were performed with different sizes of internal and external heat exchangers, and refrigerant flow rate was also considered in two-way flow devices. In addition, the heat, air, and water sources with the heat pump system were examined. The experimental results with the heat pump system were used to analyze the impact on performances. The best combination of performance was A-inside heat exchanger, B-outside heat exchanger, and B-flow device, respectively. In addition, a water heat-source was found to give roughly 40% of better performance than an air heat-source heat pump system.

Analysis on the Drying Performance with the Flow Rate of Circulation Air in a Heat Pump Dryer (순환 공기 유량의 변화를 고려한 열펌프 건조기의 성능 해석)

  • Lee, Kong-Hoon;Kim, Oak-Joong;Lee, Sang-Ryoul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.21 no.1
    • /
    • pp.1-8
    • /
    • 2009
  • The simulation of a heat pump dryer has been carried out to figure out the effect of air flow rate on the drying performance represented by MER, SMER, and so on. The simulation includes the analyses of one-stage heat pump cycle and simple drying process using the drying efficiency. The heat pump cycle with Refrigerant 134a has been considered. In the dryer, some of drying air from the drying chamber flows through the heat pump system, the rest of air bypasses the heat pump system. The two air flows joins before the drying chamber inlet. The performance parameters considered in the present study are MER, SMER, the temperature and humidity of drying air. Those parameters are compared for different total air flow rate or bypass air flow rate.

In-situ Performance Evaluation of a Ground Source Heat Pump for an Air Conditioning System (공조시스템용 지열히트펌프의 실증평가에 관한 연구)

  • Park, Youn-Cheol;Park, Seong-Koo
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.32 no.1
    • /
    • pp.66-72
    • /
    • 2008
  • In this study, the ground source heat pump was installed at a research center in Jeju Island to verify the performance of the system and to give an information for a economic feasibility. The performance test was conducted until the heat storage tank temperature reached at $5^{\circ}C$ from $50^{\circ}C$ in the cooling operation, and until the storage temperature goes up to $50^{\circ}C$ from $10^{\circ}C$ in the heating mode. As results, the system performance shows that $2.2{\sim}3.5$ for the cooling operation and $2.5{\sim}3.5$ for heating operation. It is found that the underground is good heat source for the heat pump with $3{\sim}10^{\circ}C$ variation range. The ground source heat pump could be connected one of air conditioning system without any problem in system performance. Based on the economic analysis, the initial cost for the ground source heat pump will be compensated after 4 years operation. If the system runs 20 years, approximately 300 million Won will be saved when the air conditioning system adapt the ground source heat pump based on Life Cycle Cost analysis.

Influence of the Operation Modes on the Optimum Refrigerant Charge Amount of a Heat Pump (다양한 운전모드에서 물대물 열펌프의 성능 및 최적충전량 변화에 관한 연구)

  • Boahen, Samuel;Lee, Kwang Ho;Choi, Jong Min
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
    • /
    • v.14 no.2
    • /
    • pp.15-22
    • /
    • 2018
  • As heat pump application has been extending to residential, commercial, and industrial fields, the heat pump should have many operation modes. It is required to optimize refrigerant charge amount at all operation modes in order to enhance the annual performance of heat pumps. In this study, the performance analysis of the heat pump which has cooling, heating, cooling-hot water, heating-hot water, and hot water modes was executed with the variation of refrigerant charge amount. As the refrigerant charge amount changed, the maximum COPs of the heat pump at different operation modes were changed within ${\pm}10%$. Therefore, it is highly recommended to select optimum charge amount for the heat pump based on the analysis of annual load for each operation modes.

Effect of heat pump performance improvement by use of thermal tank with temperature seperation plate (격판분리 축열조의 히트펌프 성능개선 효과)

  • Moon, Jongpil;Lee, Sunghyoun;Kwon, Jinkyung;Kang, YounKoo;Lee, Sujang
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2011.05a
    • /
    • pp.80.1-80.1
    • /
    • 2011
  • This study was carried out in order to estimate the effect of heat pump performance by use of thermal tank with 3 seperation plates which were able to divide thermal tank into 3 chambers that have different temperatures levels. For testing the effect of developed thermal tank which was installed for supplying the heat to the paprika greenhouse in Jinju city. The volume of thermal storage tank was designed for $110m^3$ which was able to cover 30% of heating capacity. The temperature difference was 3 degree Celcius between high temperature and low temperature when only heating circulation was made from heat pump to thermal tank. but 5.5 degree Celcius difference was made when heating circulation of heat pump to thermal thank and hot water supplying circulation of thermal tank to greenhouse was done simultaneously. As a result of this study showed that COP of heat pump was increased by 15% or more than that of using normal thermal tank because heat pump was able to take 3 ~ 5 degree Celcius lower thermal thank water constantly.

  • PDF