• Title/Summary/Keyword: Ventilation system control

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The Study of Jet Fan Control Logic for Longitudinal Ventilation in Road Tunnel (젯트팬 종류식 터널의 퍼지응용 제어로직에 관한 연구)

  • 유지오;남창호;신현준
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.8
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    • pp.763-770
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    • 2000
  • In tunnel ventilation, the Purpose of ventilation control is to keep the required pollution level with minimum consumption of energy But tunnel ventilation has large disturbances caused by discharge of pollutants, traffic forces especially strong for longitudinal ventilation. Hence in this paper, the tunnel ventilation control logic applying fuzzy control theories is proposed and the simulation program of tunnel ventilation control is developed. The characteristics of longitudinal ventilation with jet fans are estimated and the effect of the proposed tunnel ventilation control is verified by the simulation program.

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Evaluation of Ventilation Rate and External Air Mixing Ratio in Semi-closed Loop Ventilation System of Pig House Considering Pressure Loss (압력손실을 고려한 양돈시설의 반폐회로 환기시스템의 환기량 및 혼합비율 평가)

  • Park You-me;Kim Rack-woo;Kim Jun-gyu
    • Journal of The Korean Society of Agricultural Engineers
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    • v.65 no.1
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    • pp.61-72
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    • 2023
  • The increase in the rearing intensity of pigs has caused deterioration in the pig house's internal environment such as temperature, humidity, ammonia gas, and so on. Traditionally, the widely used method to control the internal environment was through the manipulation of the ventilation system. However, the conventional ventilation system had a limitation to control the internal environment, prevent livestock disease, save energy, and reduce odor emission. To overcome this problem, the air-recirculated ventilation system was suggested. This system has a semi-closed loop ventilation type. For designing this system, it was essential to evaluate the ventilation rates considering the pressure loss of ducts. Therefore, in this study, pressure loss calculation and experiment were conducted for the quantitative ventilation design of a semi-closed loop system. The results of the experiment showed that the inlet through which external air flows should always be opened. In addition, it was also found that for the optimum design of the semi-closed loop ventilation system, it was appropriate to install a damper or a backflow prevention device rather than a ventilation fan.

Development of an Environmental Control System for Agricultural Storage Facility (상온저장 시설의 환경 제어 시스템 개발)

  • 임종환;현명택
    • Food Science and Preservation
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    • v.4 no.2
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    • pp.101-113
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    • 1997
  • Temperature, relative humidity and ventilation are closely related one another, and they are the main factors to be controlled for the environmental control system of a storage facility. Conventional environmental control systems do not consider the interrelationship between temperature, relative humidity and ventilation, which results in low performance and high energy consumption. To overcome the inefficiency of the conventional ones, it was developed an on-off control system based on the interrelationship between the factors. The usefulness of the system was illustrated with the results produced by a set of experiments in a real world.

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A Study on the Operational Strategy for Hybrid Ventilation System in Apartment unit focused on Indoor Air Quality (실내공기질을 고려한 공동주택의 하이브리드 환기 시스템의 운영에 관한 연구)

  • Lee, Yong-Jun;Leigh, Seung-Bok;Lee, Kyung-Hoi
    • KIEAE Journal
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    • v.4 no.3
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    • pp.203-210
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    • 2004
  • This dissertation identifies and investigates the possible control modes of hybrid ventilation system in applying to general apartments. It evaluates range of hybrid ventilation control modes in terms of indoor air quality, thermal comfort, and energy consumption in a living room and a kitchen of the $1000m^2$ apartment. The TRNSYS simulation program was used for evaluating the following four ventilation types : A ventilation mode relying on only infiltration for supplying air, A natural ventilation mode considering with weather condition, A hybrid ventilation (natural + mechanical ventilation) mode allowing minimum ventilation with no heat exchange, and a hybrid ventilation mode with heat exchange. This study shows the following results. As temperature being controlled by heating cooling equipments, there is without significant difference in thermal performance among ventilation types. Regarding Indoor Air quality, Indoor air contamination level of the hybrid ventilation case consistently keep the lower levels. The hybrid ventilation modes consume more energy by a 49% as compared to the A ventilation mode relying on only infiltration for supplying air. It is caused by the continuous ventilation for keeping good indoor air quality; the increase of energy consumption can be attributable to the increase of the heating energy. Therefore, the heat exchange between indoor and outdoor air is required during heating season in severe weather conditions. During the cooling seasons, Introducing natural ventilation can achieve energy saving by 40 ~ 45%. Thus, it can be an effective strategies for energy saving. Based on these results, a hybrid ventilation system can be suggested as an effective ventilation strategy for archiving high level of indoor air quality, thermal comfort, and energy consumption.

A Study on Smoke Movement by Using Large Eddy Simulation I. Smoke Control Systems and Extraction Flowrate (대와류모사를 이용한 연기이동의 연구 I. 제연방식과 배기풍량)

  • 박외철
    • Journal of the Korean Society of Safety
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    • v.18 no.2
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    • pp.40-45
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    • 2003
  • To evaluate the smoke control systems, the large eddy simulation turbulence model based Fire Dynamics Simulate was applied to a 2m $\times$ 2m $\times$ 2.4m room with an opening. The smoke removal rate was investigated for three different smoke control systems: ventilation, extraction and pressurization. When the opening was closed, the smoke removal rates of the smoke control systems were almost the same as expected. The pressurization system showed a lower smoke removal rate compared with the other two smoke control systems for the room with the opening, and hence the pressurization system might not be efficient for a place with large openings. It was shown that the lower extraction flowrate is, the longer time the ventilation system requires to remove smoke. From these results, the ventilation system is recommended for subway stations where several large openings exist.

A study on Development and Application of Sequential Control Algorithm of Ventilation and Air Cleaning System for Improving Indoor Air Quality in School Classroom (학교교실의 실내공기질 개선을 위한 환기장치 및 공기청정기의 연동제어 알고리즘 개발 및 적용 연구)

  • Park, Hwan-Chul;Lee, Dong-Hyeon;Yee, Jurng-Jae
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.36 no.5
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    • pp.187-194
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    • 2020
  • This study presents the energy-saving sequential control algorithm to handle indoor CO2 and PM2.5 for the improvement of the air quality of school classrooms. To solve indoor air quality (IAQ) problems, air cleaning and ventilation systems are mainly used for school classrooms. Although air cleaning is able to collect PM2.5, it is difficult to remove harmful gas substances. The ventilation system is suitable to tackle CO and CO2, the volume ventilation, however, is relatively small. In this paper, to remove CO2 and PM2.5, the pollutant balance equation for improving indoor air quality is reviewed. The sequential control algorithm of the ventilation and air cleaning system with four levels of criteria is introduced for the effective removal of pollutants. The proposed sequential control algorithm confirms that indoor CO2 and PM2.5 can be properly controlled below the standard value. In addition, the sequential operation of air cleaning and ventilation systems has shown significant improvement in IAQ compared to the independent ventilation system operation. Particularly, such systems are efficient when outdoor PM2.5 is high.

Energy and Air Quality Benefits of DCV with Wireless Sensor Network in Underground Parking Lots

  • Cho, Hong-Jae;Jeong, Jae-Weon
    • International Journal of High-Rise Buildings
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    • v.3 no.2
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    • pp.155-165
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    • 2014
  • This study measured and compared the variation of ventilation rate and fan energy consumption according to various control strategies after installing wireless sensor-based pilot ventilation system in order to verify the applicability of demand-controlled ventilation (DCV) strategy that was efficient ventilation control strategy for underground parking lot. The underground parking lot pilot ventilation system controlled the ventilation rate by directly or indirectly tracking the traffic load in real-time after sensing data, using vehicle detection sensors and carbon monoxide (CO) and carbon dioxide ($CO_2$) sensor. The ventilation system has operated for 9 hours per a day. It responded real-time data every 10 minutes, providing ventilation rate in conformance with the input traffic load or contaminant level at that time. A ventilation rate of pilot ventilation system can be controlled at 8 levels. The reason is that a ventilation unit consists of 8 high-speed nozzle jet fans. This study proposed vehicle detection sensor based demand-controlled ventilation (VDS-DCV) strategy that would accurately trace direct traffic load and CO sensor based demand-controlled ventilation (CO-DCV) strategy that would indirectly estimate traffic load through the concentration of contaminants. In order to apply DCV strategy based on real-time traffic load, the minimum required ventilation rate per a single vehicle was applied. It was derived through the design ventilation rate and total parking capacity in the underground parking lot. This is because current ventilation standard established per unit floor area or unit volume of the space made it difficult to apply DCV strategy according to the real-time variation of traffic load. According to the results in this study, two DCV strategies in the underground parking lot are considered to be a good alternative approach that satisfies both energy saving and healthy indoor environment in comparison with the conventional control strategies.

A Research on the $CO_2$ Peak Point Control According to Ventilation Rate During Sleeping (취침 시 환기횟수에 따른 $CO_2$ 피크치 제어에 관한 연구)

  • Kim, Se-Hwan;Kim, Dong-Gyu;Park, Jong-Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.1
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    • pp.49-54
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    • 2009
  • Ventilation requirement of apartment was mandated according to building equipment standards in 2006. When ventilation unit was considering for indoor air quality maintenance, we needed energy saving and efficiency ventilation control methods. This study carried out experiment of ventilation rate 0.7 adequacy. When we lived in apartment, we assumed that sleeping time was long stayed time in unconsciousness. Experiments carried out ventilation rate 0, 0.1, 0.4 and 0.7 in environment chamber from 22 o'clock to 06 o'clock, the concentration of $CO_2$, temperature and humidity rate measured. Analyzing the results, conclusions are as follows. 1) When we sleep in bedroom, ventilation rate 0.4 meet the requirements of domestic legal standards. Conform fan of similarity law, ventilation rate 0.4 reduced power cost about 80% than 0.7. 2) In generally sleeping time 8 hours, peak point control reduced running time of ventilation unit about 43% than normal control.

Performance Evaluation of Multidrop Chamber Ventilation System in Apartment (공동주택내 다분기챔버형 환기시스템 적용을 통한 풍량분배 개선효과에 관한 연구)

  • Kim, Sung-Soo;Son, Jang-Yeul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.10
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    • pp.545-552
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    • 2009
  • It is common to design the duct branches where to supply the required air flow for individual room in residential apartment house. And TAB process is applied to control the designed air volume with adjusting volume dampers and/or supply diffusers after fully installing the ventilation system. This process has been resulted increasing the initial cost for the residential ventilation system because of man-hour and accessories such as volume control damper or diffuser. However it is difficult to adjust the air volume adequately in small air duct branches in residential ventilation system. The purpose of this study is to figure out the performance of Multidrop chamber coupling system for the residential ventilation system.

A NUMERICAL STUDY OF THE VENTILATION AND FIRE SIMULATION IN A ROAD TUNNEL (도로터널 환기/제연 시스템 시뮬레이션)

  • Park Jong-Tack;Won Chan-Shik;Hur Nahmkeon;Cha Cheol-Hyun
    • 한국전산유체공학회:학술대회논문집
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    • 2005.10a
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    • pp.207-212
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    • 2005
  • In designing a ventilation system of a road tunnel, a possibility of using the system as a smoke control system in case of a tunnel fire has to be considered. In the present study, a numerical simulation on ventilation system is performed considering jet fan operations and moving traffic. A fire-mode operation by reversing some fan operations in case of a tunnel fire is also simulated. The results show that ventilation operation can control the pollutants effectively, and fire-mode operation can control smoke and temperature effectively to prevent a disaster.

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