• Title/Summary/Keyword: 히트펌프 건조기

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Numerical Analysis of Flows for Agricultural Dryer with Heat Pump (히트펌프를 이용한 농산물 건조기 유동 수치해석)

  • Park, Sang-Jun;Lee, Young-Lim
    • Proceedings of the KAIS Fall Conference
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    • 2011.05b
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    • pp.676-678
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    • 2011
  • 히트펌프 사이클을 이용한 건조 공정은 최종 제품의 생산을 위하여 많은 산업 분야에 요구되는 필수 공정으로 본 논문에서는 대형 히트펌프 건조기의 상부 분리대의 가이드 베인의 형상 및 수량을 최적화 하였다. 이를 위해 팬은 성능곡선 모델을 사용하였고, 증발기와 응축기는 다공성 매질로 가정하였다. 이는 팬을 통과하여 가이드 베인을 따라 건조기 입구로 들어가는 바람의 균일도를 예측할 수 있어 설계 정확도 향상에 기여할 수 있다.

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A Study on Cycle and Flow Analysis for Improvement of Energy Efficiency of a Heat Pump Dryer with Hot Bypass Gas and Air Dampers During Warm-up Stage (고온 우회가스 및 에어댐퍼 사용을 통한 히트펌프 건조기 승온단계 에너지 효율 향상을 위한 사이클 및 유동해석 연구)

  • Park, Sang-Jun;Hwang, Il-Sun;Lee, Young-Lim
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.9
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    • pp.3827-3834
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    • 2012
  • Recently, instead of hot air type dryers that require a lot of heat, energy-efficient heat pump dryers have been used in various fields such as paper, textile, wood, food, etc. In this paper, the characteristics of heat pump cycle were theoretically evaluated with hot-gas bypass system to further improve the energy efficiency by minimizing the use of electric heaters in early warm-up stage of the dryers for frozen agricultural products. In addition, damper system that leads outside air to flow into the dryer were optimized to obtain extra heat for higher energy efficiency.

Study on Design Technology of Heat Pump Cycle for High Temperature Performance (고온 생산용 열펌프 사이클 설계)

  • Kim, Jong-Ryul;Kim, Seok-Young;Kim, Yong-Min;Lee, Kong-Hoon;Kim, Ook-Joong;Yi, Sung-Chul;Jung, Chi-Young;Kim, Jong-Ryeol
    • Journal of Energy Engineering
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    • v.19 no.4
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    • pp.228-233
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    • 2010
  • About 55% of total energy is consumed in the industrial division. The industrial heat pump application will show magnificent energy saving effect as well as higher cost efficiency because of larger energy consuming volume of each facility and longer operation hour and higher stability against seasonal temperature change. Over 90% of dryer for industrial usage has hot wind heat source and hot wind dryer is the representative type covering 68.7% while its 30 ~ 50% lower heat efficiency causes lots of energy loss by exhaust air. Re-usage of exhaust air can improve energy efficiency of dryer because 68% heat energy or 78% of hot air lose in exhaust air. Therefore, high temperature heat pump dryer can be the best alternative. Comparing to the existing dryer with 30% ~ 50% energy efficiency, newly developing high temperature heat pump dryer will enhance energy efficiency up to 60% ~ 80% efficiency. In this paper, heat pump system for high temperature was designed, constructed and tested. The results have shown that system COPh is estimated as 3.3.

Optimal Flow Design of High-Efficiency, Cold-Flow, and Large-size Heat Pump Dryer (히트펌프를 이용한 고효율 냉풍 대형 건조기 유동 최적설계)

  • Park, Sang-Jun;Lee, Young-Lim
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.5
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    • pp.547-552
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    • 2011
  • Drying process, corresponding to a final process in the area of food engineering, requires a lot of heat energy. Thus, the energy efficiency is very important for dryers. Since the energy efficiency of heat pump dryers is much higher compared to that of electric dryers or other types of dryers, most of large-capacity dryers are adopting heat pump. In this study, shapes, positions and number of air-circulating fans, guide vanes, air inlet, outlet and top separator were varied for optimization of the flow of a large-capacity heat pump dryer. In addition, fans were modelled with performance curves and porous media were assumed for foods and heat exchangers. The simulation results were applied to the 12-ton dryer and the velocity distributions were experimentally examined. Finally, uniform drying in time was successfully accomplished through frozen pepper experiment.

A Study on Performance Improvement of a Heat Pump Dryer with an Extra Evaporator Outside (보조 외부 증발기를 이용한 히트펌프 건조기 성능 향상에 관한 연구)

  • Lee, Young-Lim;Park, Sang-Jun;Hwang, Il-Sun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.10
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    • pp.711-717
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    • 2012
  • A heat pump dryer for the frozen food needs to preheat the air to a certain temperature where condensation can efficiently occur. In this study, an analysis of a heat pump dryer performance with operating conditions, an analysis of supplying heat with internal and external evaporators and a warm-up experiment with the evaporators have been performed. The results showed that the external evaporator can significantly accelerate the warm-up time of the dryer, so that it can reduce power consumption greatly. The use of the external evaporator is more efficient for higher ambient temperature. In addition, it was found that COP decreases and the range of evaporating pressure for the evaporator becomes narrower as the condensing temperature of the condenser increases.

Experimental Study on the Heat Transfer Capacity and Dehumidification Performance of a Parallel Flow Evaporator for a Heat Pump Dryer (히트펌프 건조기용 PF 증발기의 능력과 제습량 실험 연구)

  • Kwon, Young Chul;Kim, Ki Young;Lee, Seok Hyun;Kwon, Jeong Tae
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.9
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    • pp.516-521
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    • 2013
  • In the present study, the performances of a fin-tube evaporator and three PF evaporators for a heat pump dryer were experimentally investigated. Among the tested evaporators, the PF3 type evaporator showed the highest values of heat transfer capacity and dehumidification performance, while the fin-tube evaporator had the lowest values. PF3 showed better performance compared to PF1 and PF2, due to the large pin pitch, which leads to more draining for dehumidified water. Also, the $45^{\circ}$ inclined PF evaporator presented better performance than that of the $90^{\circ}$ inclined PF evaporator, owing to its easier draining characteristics. The effect of air velocity was revealed to be quite large. When the air velocity increased by 20%, the heat transfer capacity and dehumidification performance increased 43%/11%, 48%/13% and 54%/23% for PF1, PF2 and PF3, respectively.

Energy Performance Analysis of Electric Heater and Heat Pump Food Dryers (전기히터식 및 히트펌프식 식품 건조기의 에너지 성능 비교)

  • Yu, Young Woo;Kim, Young Il;Park, Seungtae
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.11 no.4
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    • pp.1-6
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    • 2015
  • In this study, energy performance of two types of food dryers which are electric heater and heat pump is studied experimentally. With drying chamber temperatures controlled at 45, 50 and $55^{\circ}C$, sliced radish is dried from an initial mass of 90 to final 7 kg. Moisture content, drying time, total power consumption, MER (moisture extraction rate, kg/h) and SMER (specific moisture extraction rate, kg/kWh) are measured and analyzed. As the drying chamber temperature is increased, drying time is shortened but energy efficiency is reduced for both types. For an electric heater dryer, the effect of chamber temperature on drying time is significant but less significant on energy efficiency. For a heat pump dryer, the dependence of chamber temperature on drying time is weak but strong on energy efficiency. Temperature levels have little effect on electric heater dryer performance but strong effect on heat pump dryer which operates on a vapor compression refrigeration cycle. The energy performance of the heat pump dryer is superior with an average SMER of 2.175 kg/kWh which is 2.22 times greater than that of the electric heater dryer with SMER of 1.224 kg/kWh.

Experimental Study on the Performance of Heat Recovery Heat Pump System using R245fa Refrigerant (R245fa 냉매를 이용한 배열회수 히트펌프 시스템 성능에 관한 실험적 연구)

  • Kim, Hyuntaek;Kim, Yongchan;Cha, Dongan;Kwon, Ohkyung
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.10
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    • pp.408-413
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    • 2016
  • The objective of this study is to investigate the performance of a heat recovery heat pump dryer using a R245fa refrigerant experimentally. In this study, the main components of the heat pump dryer were an evaporator, a compressor, a condenser, and an expansion valve. As a result, when the amount of refrigerant varied from 15 kg to 16 kg, the hot air outlet temperature in the condenser and the heat transfer rate were almost kept constant. Therefore, the amount of refrigerant at 16 kg was considered to be a suitable amount in the heat pump. As the air inlet velocity varied from 0.5 m/s to 1.5 m/s, the highest temperature in the condenser could be obtained when the air inlet velocity was 0.5 m/s. The heat transfer rate, system (COP), and hot air outlet temperature were 5.6 kW, 3.4, and $102.5^{\circ}C$, respectively, when the bypass ratio and water temperature were 0% and $60^{\circ}C$.

Analyses of Power Consumption of the Heat Pump Dryer in the Automobile Drying Process by using the Principal Component Analysis and Multiple Regression (주성분 분석과 다중회귀모형을 사용한 자동차 건조 공정의 히트펌프 건조기 소모 전력 분석)

  • Lee, Chang-Yong;Song, Gensoo;Kim, Jinho
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.38 no.1
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    • pp.143-151
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    • 2015
  • In this paper, we investigate how the power consumption of a heat pump dryer depends on various factors in the drying process by analyzing variables that affect the power consumption. Since there are in general many variables that affect the power consumption, for a feasible analysis, we utilize the principal component analysis to reduce the number of variables (or dimensionality) to two or three. We find that the first component is correlated positively to the entrance temperature of various devices such as compressor, expander, evaporator, and the second, negatively to condenser. We then model the power consumption as a multiple regression with two and/or three transformed variables of the selected principal components. We find that fitted value from the multiple regression explains 80~90% of the observed value of the power consumption. This results can be applied to a more elaborate control of the power consumption in the heat pump dryer.