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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Journal of Air-Conditioning and Refrigeration Engineering
Journal Basic Information
Journal DOI :
The Society of Air-Conditioning and Refrigerating Engineers of Korea
Editor in Chief :
Volume & Issues
Volume 25, Issue 12 - Dec 2013
Volume 25, Issue 11 - Nov 2013
Volume 25, Issue 10 - Oct 2013
Volume 25, Issue 9 - Sep 2013
Volume 25, Issue 8 - Aug 2013
Volume 25, Issue 7 - Jul 2013
Volume 25, Issue 6 - Jun 2013
Volume 25, Issue 5 - May 2013
Volume 25, Issue 4 - Apr 2013
Volume 25, Issue 3 - Mar 2013
Volume 25, Issue 2 - Feb 2013
Volume 25, Issue 1 - Jan 2013
Selecting the target year
Development of an HVAC&R Systems Energy Evaluation Methodology and Simulation Program for Office Buildings
Cho, Jinkyun ; Shin, Seungho ; Kim, Jonghurn ; Hwang, Dongkon ; Hong, Hiki ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 25, issue 7, 2013, Pages 363~370
DOI : 10.6110/KJACR.2013.25.7.363
HVAC&R systems are the most energy consuming building services, representing approximately half of the final energy use in the building sector. Despite their significant energy use, there is a lack of a consistent and homogeneous framework to efficiently guide research. This research is about the energy consumptions of HVAC&R systems, with the aim of establishing a common idea for the analysis of building energy efficiency. Our approach deals with the concept of an HVAC&R set that is composed of subsystems. A matrix combination evaluation is examined, and a total of 960 sets can be implemented in a large scale office building. A method as a tool for energy evaluations of HVAC&R systems, and HEET as a energy simulation program, were developed.
Energy Consumption Analysis based on Filter Differential Pressure when Adopting an Air-side Economizer System for a Data Center
Park, Seonghyun ; Seo, Janghoo ; Jung, Yong-Ho ; Chang, Hyun-Jae ; Hwang, Seok-Ho ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 25, issue 7, 2013, Pages 371~376
DOI : 10.6110/KJACR.2013.25.7.371
Recently, many studies related to reducing the energy consumption in data centers have been conducted. These studies have mainly focused on the air intake and exhaust system of a computer room air handling unit (CRAH) in the server room, diffuser type, suppression and discharge of the heat generated from the server, and the air-side economizer system. In this study, the energy consumption of the conventional central chilled water cooling system is compared with the energy consumption of the air-side economizer system. We also examined how changes of differential pressure by each filter have influenced energy consumption, using the power usage effectiveness (PUE). Results show that the PUE was improved, and energy consumption decreased, by applying the air-side economizer system.
Investigation of Local Flow Parameters Caused by Flow Acceleration Corrosion Downstream of an Orifice in a Piping System
Kim, Kyung-Hoon ; Cho, Yun-Su ; Kim, Hyung-Joon ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 25, issue 7, 2013, Pages 377~385
DOI : 10.6110/KJACR.2013.25.7.377
In this study, the performance of an impeller according to blade length and pitch angle was studied experimentally by building a variable pitch impeller while changing blade length to review the effect of blade length and pitch angle on a fan`s performance. The pitch angle was changed in six steps from
at intervals of
while the blade lengths were changed to 90 mm, 100 mm, 110 mm and 120 mm with an identical airfoil shape while carrying out the experiment. The results are summarized as follows : The air flow per static pressure of axial fans increased linearly with increase of pitch angle, but the high static pressure showed a decrease at a pitch angle of
. The shaft power increased proportionally to the pitch angle at all blade lengths; the larger the pitch angle, the larger the measured increase of shaft power. This is because the drag at the fan`s front increases with the pitch angle. In the axial fans considered in this research, the flow and incre.
Cooling and Heating Operation Characteristics of Raw-water Source Heat Pump and Air Source Heat Pump in Water Treatment Facility
Oh, Sun-Hee ; Yun, Rin ; Cho, Yong ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 25, issue 7, 2013, Pages 386~391
DOI : 10.6110/KJACR.2013.25.7.386
The dynamic characteristics of both raw-water source and air source heat pump utilized in water treatment facilities were investigated by using TRNSYS simulator. The modeling of the raw water source heat pump was verified by the measured data at the Cheongju water treatment facility, and the modeling at the air source heat pump was verified by the data from the Siheung water treatment facility. The average heating and cooling COPs from the raw-water source heat pump were higher than those of the air source heat pump by 19% and 18%, respectively. The power consumptions of the air source heat pump for the cooling and the heating were higher than those of the raw water source heat pump by 28% and 26%, respectively.
EA Study on the Operation Performance of Central Plant Equipment According to Part Load Characteristics
Lee, Wang-Je ; Kang, Eun-Chul ; Lee, Euy-Joon ; Oh, Byung-Chil ; Shin, U-Cheul ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 25, issue 7, 2013, Pages 392~397
DOI : 10.6110/KJACR.2013.25.7.392
To fulfill the demands concerning energy efficiency for zero energy buildings, various technologies of architects and engineers are required. This study aims to estimate the thermal performance of heat source equipment in which part load characteristics are considered in an office building. Overestimation of heat source equipment was reviewed through literature survey, and heating and cooling loads depending on the capacity and division of the equipment were analyzed through a simulation program (DOE-2.1E). The conclusions gained from this study are as follows; 1) The more the division of equipment, the less the heating and cooling energy consumption. 2) When a large item of equipment is divided into two small items of equipment, the optimum application rate showed as 5:5 for chiller, and 7:3 for boiler, respectively.
Numerical Simulation of a System Heat Pump Adopting an Integral Optimum Regulating Controller
Kim, Yongchan ; Choi, Jong Min ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 25, issue 7, 2013, Pages 398~405
DOI : 10.6110/KJACR.2013.25.7.398
Small and medium-size buildings employ a multi-distributed individual air-conditioning system that utilizes package air conditioners instead of centralized cooling systems, which can allow easier building management and maintenance, along with a diversification of facility use. Inverter driven system heat pumps have been developed to achieve not only an easy distribution control, allowing free combination of indoor units with different models and different capacities, but also wide applications to intelligent air conditioning. However, the control algorithms of the system heat pump are limited in the open literature, due to complicated operating conditions. In this paper, an inverter-driven system heat pump having two indoor units with electronic expansion valves (EEV) was simulated in the cooling mode. An integral optimum regulating controller employing the state space control method was also simulated, and applied to the system-heat pump system, to obtain efficient control of the MIMO (multi input multi output) system. The simulation model for the controller yielded satisfactory prediction results. The new control model can be successfully utilized as a basic tool in controller design.
Dynamic Modeling and Simulation of a Hybrid Heat Pump
Shin, Younggy ; Kim, Jae Hyun ; Yoo, Byeong Jun ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 25, issue 7, 2013, Pages 406~412
DOI : 10.6110/KJACR.2013.25.7.406
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.
Performance Analysis of an ORC System for Two Different Working Fluids
Chang, Hong-Soon ; Song, Yeong-Kil ; Han, Young-Sub ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 25, issue 7, 2013, Pages 413~417
DOI : 10.6110/KJACR.2013.25.7.413
The organic Rankine Cycle (ORC) uses a kind of refrigerant as a working fluid that evaporates at relatively low temperature, as the Rankine Cycle uses superheated steam as the working fluid. A small scale ORC test bench was installed, and two different working fluids (R245fa and R134a) were injected into the test bench. The test bench was in operation with the two different working fluids under the same conditions. The effects against the system performance from the different working fluids were analysed, and root causes were identified. Other factors reflecting the power generation efficiency were also found. A conclusion was drawn, that R245fa makes the system perform better, than R134a.
Subway Station`s Seating Capacity of Temporary Evacuees from Disastrous Situation through Analyzing the Number of Toilets
Sohn, Byonghu ; Hwang, Eun-Kyoung ;
Korean Journal of Air-Conditioning and Refrigeration Engineering, volume 25, issue 7, 2013, Pages 418~426
DOI : 10.6110/KJACR.2013.25.7.418
With advantages of open spaces and existing HVAC facilities, subway station, if unexpected disastrous situation happens on the ground, can be used as a temporary safe place for evacuees. The main objective of this study is to establish a guideline on estimating evacuation capacity of the subway station and evaluating levels of service of evacuation for officials to control the situation. This guideline includes available spaces of the station, capacity of sanitary fixtures, and total number of passengers, etc. In this paper, we first analyzed the number of passengers of SMRT (Line 5~Line 8) during AM peak hour and then evaluated the number of passengers using toilets at that time. In addition, we calculated the seating capacity of subway stations on SMRT using the difference between the actual number of toilets and the estimated number of ones from the occupancy time of each toilet.