• Title/Summary/Keyword: 공기조화기

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The Study of Air Sampling Smoke Detector (공기흡입형 연기감지장치에 관한 연구)

  • 이복영;이병곤
    • Fire Science and Engineering
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    • v.17 no.4
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    • pp.86-91
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    • 2003
  • Since the air stream in the room controlled by HVAC system affects on he expected response of conventional detectors which are designed in accordance with normal characteristics of air stream in the fire incident, unexpected operation time delay may occur in fire. In order to solve this problem and to improve sensitivity so that to initiate fire in its early stages for minimizing damage and protecting people, we studied and developed Air Sampling Smoke Detector. The Air Sampling Smoke Detector is a kind of active-type fire detection system. it draws air continuously from the protected area through an air sampling pipe network to the smoke density analyzer. This study presents smoke density analysing technique and air intake balancing technique through an air sampling pipe network. As a result of evaluating, Air Sampling Smoke Detector was much more sensitive than conventional smoke detectors that passively wait for smoke to reach them and was not affected by ambient airflow in the room by means of balanced air intake through the sampling holes.

Sound Calculation and Noise Control in a Building (건물의 실내소음레벨 영향 평가)

  • 김두훈
    • Journal of the KSME
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    • v.35 no.10
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    • pp.886-895
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    • 1995
  • 근래들어 도시의 집중화와 고밀도화, 교통량의 증대 등 사회구조의 급격한 변화로 각종 소음원 들이 증가하고 있으며 소음에 대한 일반인의 관심도 점차 높아지고 있다. 건물의 경우 한정된 공간에서 거주자의 생활을 보다 쾌적하고 편리하게 하기 위해서 각종 설비들이 증가되고, 이들 설비들은 대용량화하는 추세에 있다. 건물내 공간의 기능을 능률적으로 유지하기 위해 설치된 각종 장비(공기조화기, 펌프, cooling tower, 보일러, 냉동기 \ulcorner 발전기 등)에서 발생하는 소음이 직접 실내로 투과되거나 이들이 발생하는 진동이 건물 구조체로 전달되어 실내소음을 야기시키는 경우가 많다. 따라서, 건물을 설계할 때는 실별 용도에 따라 허용소음도를 결정한후 이러한 실내 소음환경을 달성하기 위해 각종 조처를 강구하게 되는데, 이 글에서는 이러한 건물의 실내 소 음도 영향 평가의 하나로 특정 건물의 예를 들어 소음도 계산과 소음의 원인 및 대책에 관해 기술하고자 한다.

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Control Methods of the VAV Air Handling Unit for the Required Outdoor Air Demand (변풍량 공조시스템의 요구외기량 확보를 위한 제어방식)

  • Han, Do-Young;Joo, Young-Duk;Kim, Jin;Lee, Jun-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.3
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    • pp.203-209
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    • 2003
  • Control algorithms of an air handling unit by using the mixing box plenum pressures were developed and verified by experiments. Control algorithms developed for this study were the setpoint algorithms for the outdoor damper position, the outdoor/fixed plenum pressure, and the return/exhaust plenum pressure. The outdoor/fixed plenum pressure setpoint was used to control the bypass damper position, and the return/exhaust plenum pressure setpoint was used to control the return fan speed. Experimental results showed the good control of the required outdoor air demand. Therefore, setpoint algorithms developed for this study may effectively be applied for the control of the VAV air handling unit.

An Experimental Study on the Measurement Error in the Performance Testing of Air Conditioners Using a Psychrometric Calorimeter (건습구식 칼로리미터를 이용한 공기조화기 성능측정상의 계측오차에 대한 실험적 연구)

  • 김봉훈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.5
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    • pp.415-423
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    • 2002
  • An experimental study using a psychrometric calorimeter was conducted to investigate the temperature and pressure mea surement errors permitted for determining cooling capacity of an air conditioner. First, the instrument calibration was made in accordance with the related test methods and guidelines in order to accurately evaluate basic performance (cooling capacity and airs flow rate). Secondly, a parametric study was performed to examine the effect of measurement error involved if temperature and pressure measuring instruments on the cooling capacity calculation. From the results, it was found that the degree of accuracy for both temperature and pressure measurements played an important role on the error occurring in the determination of cooling capacity and needed to be maintained within a certain value to guarantee required accuracy of cooling capacity.

Evaluation of Energy Consumption of HVAC System for Air Filter Pressure Difference Change in Commercial Buildings (공조설비의 필터차압 변화에 따른 에너지 소비성능 평가)

  • Won Keun-Ho;Kwak Ro-Yeul;Huh Jung-ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.12
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    • pp.1227-1233
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    • 2004
  • Air handling unit (AHU)'s air filter pressure difference is important for energy consumption and indoor air quality. Both energy Performance data and air filter differential pressure of AHU in real office buildings were monitored and analyzed to investigate quantitatively energy impact as dust buildup level on air filter grows. We also modeled and simulated CAV system using HVACSIM+ program to examine the energy effect of dust buildup on filters. Through analysis of time series pressure drop data, the filter pressure difference rate has been increased due to cumulative supply air flow rate increase. As filter pressure drop increased to 1 inch water column, it is found that the supply air flow rate was decreased by 10%, the chilled water flow rate was increased by 5.9% and the pump energy consumption was increased to 5.9%.

Prediction of Characteristics for the Air-side Particulate Fouling in Finned-Tube Heat Exchangers of Air Conditioners used in the Field (실공간 사용 공기조화기용 열교환기의 공기측 파울링 특성 예측)

  • Ahn, Young-Chull;Jung, Sung-Hak;Hwang, Yu-Jin;Lee, Chang-Gun;Kim, Doo-Hyun;Jung, Seong-Ir;Lee, Jae-Keun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.8
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    • pp.563-568
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    • 2007
  • The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performances of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. An empirical modeling equation has been derived from the experimental results using accelerated tests and it showed good predictions of the fouling characteristics of the slitted finned tube heat exchangers. However the modeling equation predicts only the fouling characteristics of new heat exchangers and it can not predicts fouling characteristics obtained from actual field data which contains the effect of hydrophilicity deterioration. Therefore an modified modeling equation is proposed and it shows good predictions of the actual fouling characteristics of finned-tube heat exchangers.

Thermal Design of a Cooling Coil for Building Air Conditioning (건물 공조용 냉수 코일의 열 설계)

  • Kim, Nae-Hyun;Byun, Ho-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6445-6452
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    • 2015
  • The surface of the cooling coil becomes dry, wet or partially wet depending on the operating condition. Thus, a proper design of the cooling coil should include a heat transfer analysis on dry, wet or partially wet surfaces. In this study, an elementary model, which analyzes the cooling on an elementaty basis, is proposed. Comparison of the predictions of the model with experimental data of the cooling coil revealed that heat transfer rates were predicted within 10.1%, airside pressure drop within 11.1% and sensible heat ratio within 5.7%. The model was used to investigate the effect of water circuitory on cooling coil performance.

Development of Simulation Program of Automotive Engine Cooling System (자동차 엔진냉각계의 해석 프로그램의 개발)

  • 배석정;이정희;최영기
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.11
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    • pp.943-956
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    • 2003
  • A numerical program has been developed for the simulation of automotive engine cooling system. The program determines the mass flow rate of engine coolant circulating the engine cooling system and radiator cooling air when the engine speed is adopted by appropriate empirical correlation. The program used the method of thermal balance at individual element through the model for radiator component in radiator analysis. This study has developed the program that predicts the coolant mass flow rate, inlet and outlet temperatures of each component in the engine cooling system (engine, transmission, radiator and oil cooler) in its state of thermal equilibrium. This study also combined the individual programs and united into the total performance analysis program of the engine cooling system operating at a constant vehicle speed. An air conditioner system is also included in this engine cooling system so that the condenser of the air conditioner faces the radiator. The effect of air conditioner to the cooling performance, e.g., radiator inlet temperature, of the radiator and engine system was examined. This study could make standards of design of radiator capacity using heat rejection with respect to the mass flow rate of cooling air. This study is intended to predict the performance of each component at design step or to simulate the system when specification of the component is modified, and to analyze the performance of the total vehicle engine cooling system.

공동주택 세대간 생활소음 저감을 위한 소음기 개발

  • Lee, K.H.;Kwon, B.H.;Lee, J.H.;Oh, J.H.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1450-1454
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    • 2007
  • 주상복합형 주거공간에 각 실간 Cross Talking에 의한 소음을 저감시키고 실내기의 공기조화로 발생하는 팬의 소음을 저감 시키기 위하여 소음 환기 장치를 개발 하였다. 공명형과 팽창형의 특성을 적용한 복합적 소음기로 저감주파수 대역에 따른 설계가 가능하며 이 소음기 성능시험 결과 특정 주파수 대역에서 20dB이상의 삽입손실치가 발생하고, 삽입에 의한 압력손실 2mmAq 이하가 됨을 확인하였다. 본 개발품의 특성은 구조가 간단하고 분해조립이 가능하여 설치 및 유지보수가 용이한 제품이다.

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A Study on the Heat Transfer Characteristics of Liquid Droplet Radiator for Air Conditioning (공기조화용 액적방열기의 열전달특성에 관한 연구)

  • 김금무;김춘식;김용모;김종헌
    • Journal of Advanced Marine Engineering and Technology
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    • v.19 no.4
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    • pp.17-26
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    • 1995
  • In general existing air conditioning devices, which are carried out by convection heat transfer, are very popular compared with the radiation type air conditioning devices. But perconal convection tpe air conditioning units are unuseful air conditioning type because it handles amount of surrounded air to meet the temperature and humidity. In this view, this study is intended to develope personal dir conditioning units using a radiation type radiator. Liquid Droplet Radiator(L.P.R.) radiates the energy by means of thermal radiation. Radiative energy from L.P.R. is the infrared rays which heat the objects without lose of energy. It is a desirable heating method for the local area within the large room. In this study, the analysis uses the Monte Carlo methd to predict the temperature distribution in the droplet sheet and the net heat flux from the L.D.R.. And for this study and experiment was carried out to analyse the radiative and convective heat transfer characteristics in the L.D.R.. And the experiment was investigated the effects of inlet temperature, feed rate, optical thickness and droplet diameter on heat transfer characteristics of L.D.R.. The obtained results from the numerical and experimental studies of L.D.R. were as follows ; (1) The heat flux of L.D.R. was effected by extinction coefficient of droplet sheet, optical thickness and droplet temperature, surface area and emissivity of the droplet. And it was increased with the temperature, feed rate and optical thickness, on the other hand decreased with increasing of droplet diameter. (2) The experimental results for heat flux was ecalucted below 20% than that of the numerical solution by Monte Carlo method, but the tendency of the variation shows relatively good agreement.

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