• 제목/요약/키워드: Heat pump using of CO2

검색결과 93건 처리시간 0.032초

하수열을 이용한 냉난방시스템에 관한 연구 (Heating and Cooling System using the Sewage Source Absorption Refrigeration and Heat Pump Cycle)

  • 이용화;신현준;윤희철;박현건
    • 한국태양에너지학회 논문집
    • /
    • 제27권4호
    • /
    • pp.19-26
    • /
    • 2007
  • This paper concerns the study of absorption refrigeration and heat pump cycle to use sewage. Simulation analysis on the double-effect absorption refrigeration cycle with parallel and two-stage heat pump cycle has been performed. The working fluid is Lithium Bromide and water solution. The absorption refrigeration cycle use sewage as a cooling water for the absorber and condenser, and absorption refrigeration cycle does that as a chilled water for the evaporator of the first stage cycle. And the two-stage cycle consists of coupling double-effect with parallel and single effect cycle so that the first stage absorber and condenser produces heating water to evaporate refrigerant in the evaporator of the second stage. The effects of operating variables such as a absorber temperature on the coefficient of performance have been studied for absorption refrigeration and heat pump cycle.

연료전지 자동차 열방출 시스템의 설계 (Design of a Heat Release System for Fuel Cell Vehicles)

  • 김성철;박민수;정승훈;윤석호;김민수
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 한국신재생에너지학회 2005년도 제17회 워크샵 및 추계학술대회
    • /
    • pp.545-548
    • /
    • 2005
  • There is a close relation between the heat generation in the fuel cell stack and the fuel cell performance. In PEM fuel Gell vehicles, the stack coolant temperature is about $65^{\circ}C$, which is far lower than that for general automobile engine. Therefore, it is hard to release heat generated in the stack by using a radiator of limited size because of the reduced temperature difference between the coolant and the ambient air. In this study, indirect stack cooling system using $CO_2$ heat pump was designed and its stack cooling performance in releasing heat to the ambient was investigated. This work focuses on a series of processes that grasp the relation among the fuel cell power, the radiator capacity and the stack temperature. The purpose of this work is to find out a way to properly release sufficient amount of heat through the finite sized radiator, so that the stack power general ion can not be deteriorated due to the stack temperature increase. The optimization between the compressor power consumption and the fuel cel1 output power can be carried out to maximize the performance of fuel cell system.

  • PDF

연료전지 자동차 열방출 시스템의 설계 (Design of a Heat Release System for Fuel Cell Vehicles)

  • 김민수;김성철;박민수;정승훈;윤석호
    • 신재생에너지
    • /
    • 제1권4호
    • /
    • pp.49-54
    • /
    • 2005
  • There is close relation between the heat generation in the fuel cell stack and the fuel performance. In PEM fuel cell vehicles, the stack coolant temperature is about $65^{\circ}C$, which is far lower than that for general automobile engine. Therefore, it is hard to release heat generated in the stack by using a radiator of limited size because of the reduced temperature difference between the coolant and the ambient air. In this study, indirect stack cooling system using $CO_2$ heat pump was designed and its stack cooling performance in releasing heat to the ambient was investigated. This work focuses on a series of processes that grasp the relation among the fuel cell power, the radiator capacity and the stack temperature. The purpose of this work is to find out a way to properly release sufficient amount of heat through the finite sized radiator, so that the slack power generation can not be deteriorated due to the stack temperature increase. The optimization between the compressor power consumption and the fuel cell output power can be carried out to maximize the performance of fuel cell system.

  • PDF

1-D 시뮬레이션을 이용한 히트펌프 기술과 결합된 연료전지 스택용 냉각 시스템 개발 (Developing a Cooling System for Fuel Cell Stacks Combined with Heat Pump Technology Using 1-D Simulation)

  • 정상민;박동규;김민수;나성욱;이승준;권오성;이철희
    • 드라이브 ㆍ 컨트롤
    • /
    • 제21권2호
    • /
    • pp.1-7
    • /
    • 2024
  • This paper proposes a novel cooling system for hydrogen fuel cell cooling systems by integrating heat pump technology to enhance operational efficiency. The study analyzed the cooling efficiency of the fuel cell cooling system. With the increasing focus on eco-friendly vehicle technologies to address environmental concerns and global warming, the transportation sector, a major contributor to greenhouse gas emissions, needs technological enhancements for better efficiency. The proposed cooling system was modeled through 1-D simulations. The analysis results of parameters such as thermal balance, temperature, and pressure of each component confirmed the stable operation of the system. By examining variations in the cooling system's flow rate, compressor RPM, and the Coefficient of Performance (COP) based on different refrigerants, initial research was conducted to derive optimal operating conditions and parameter values.

2중열원 히트펌프시스템의 냉방성능예측에 관한 연구 (Cooling Performance Evaluation study of Dual-Source Heat Pump System)

  • 노관종;김지영;강은철;박희문;이의준
    • 한국지열·수열에너지학회논문집
    • /
    • 제3권1호
    • /
    • pp.1-9
    • /
    • 2007
  • A steady-state simulation model for Dual-Source Heat Pump(DSHP) of 8RT was presented. A Dual-Source Heat Pump(DSHP) has been designed to make up for the conventional air source heat pumps. The performance evaluation has been conducted under internal standard test conditions such as ISO-13256-1 and KS C 9306. However, as test conditions such as entering water, indoor and outdoor air conditions could not be controlled to satisfy the standard test conditions in outdoor tests, a series of experiments have been conducted with the actual test conditions. Then, computer models for DSHP could be used for the standard condition have developed using EES program. The model was developed from basic thermodynamic principles and heat transfer relations. Most of the parameters were obtained with EES from the actual catalog data. The simulation results were in good agreement with the experiments.

  • PDF

트윈로터리 압축기 적용 냉방 및 급탕 겸용 이산화탄소 시스템의 성능특성에 관한 연구 (Performance Characteristics of a CO2 Cooling and Water Heating System with a Twin-rotary Compressor)

  • 조홍현;이호성;백창현;김용찬;조성욱
    • 설비공학논문집
    • /
    • 제20권4호
    • /
    • pp.230-237
    • /
    • 2008
  • The objective of this paper is to investigate the performance characteristics of a $CO_2$ cooling and water heating system using a twin-rotary compressor with the compression volume ratio of 0.6. The cooling performances of the $CO_2$ heat pump were measured and analyzed with the variations of charge amount, EEV opening, and compressor frequency. In addition, the performance of the combined system including cooling and water heating was also measured and analyzed by varying inlet temperature of the EEV. As a result, the optimal normalized charge and cooling COP in the cooling mode were 0.307 and 2.06, respectively. The application of the water heating into the $CO_2$ heat pump improved the cooling performance over 78% and decreased the EEV inlet temperature by $8^{\circ}C$, which can increase system reliability.

냉매 열교환기 구성방법에 따른 제 2종 흡수식 히트펌프의 성능 특성 변화에 관한 연구 (Performance Characteristics of Type II LiBr-H2O Absorption Heat Pump in Accordance with the Refrigerant Heat Exchanger Configuration)

  • 이창현;윤준성;김인관;권오경;차동안;배경진;김민수;박찬우
    • 설비공학논문집
    • /
    • 제29권7호
    • /
    • pp.373-384
    • /
    • 2017
  • The objective of this study was to determine the effect of refrigerant heat exchanger on the performance of type II absorption heat pump performance using numerical analysis. Two heat exchange installation methods were used: solution to refrigerant and waste hot water to refrigerant. These methods were compared to the standard model of hot water flow without using refrigerant heat exchanger. When waste hot waters were bypassed to refrigerant heat exchanger, COP was not affected. However, steam mass generation rates were increased compared to those of the standard model. When solutions were bypassed to the refrigerant heat exchanger, results were different depending on the place where the solution rejoined. COP and steam mass generation rates were lower compared to those when waste heat water was passed to refrigerant heat exchanger. Thus, it is possible to obtain higher steam mass generation rates by using waste water and installing refrigerant heat exchanger.

설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
    • /
    • 제26권12호
    • /
    • pp.605-619
    • /
    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

건물구조체를 이용한 수평형 지열시스템의 시공법에 관한 연구 (Study on construction method of horizontal ground heat pump system using the building structure)

  • 채호병;남유진
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2013년도 추계 학술논문 발표대회
    • /
    • pp.139-140
    • /
    • 2013
  • Ground source heat pump systems can achieve the energy saving of building and reduce CO2 emission by utilizing stable ground temperature. However, they have many barriers such as high cost of installation, incompletion of design tool, lack of recognition as heating and cooling systems. In order to solve the problems, the building integrated geothermal system (BIGS) developed by several researches which use building foundation as a heat exchanger. In order to establish the optimum design tool of BIGS with the horizontal heat exchanger, the prediction method of ground heat exchange rate developed with numerical simulation model. In this study, the economic analysis for BIGS was conducted based on simulation results and the optimal design method was suggested. As a result, it was found that the case of 32 A, piping space 0.3 m, piping deep 0.5 m and flow rate 9.52 L/min was the best case as 50.1 W/m2 of heat exchange rate. In this case the initial cost was reduced to 115 million won.

  • PDF