Loading [MathJax]/jax/output/CommonHTML/jax.js
  • Title/Summary/Keyword: heating control system

Search Result 770, Processing Time 0.037 seconds

Research Study on Seoul Region School Nutritionists' Perception of Potentially Hazardous Foods and Execution Conditions of Managing CCP Control Standard of the HACCP System - Focusing on CCP 3~CCP 7 - (서울지역 학교 영양(교)사의 PHF에 대한 인식 및 CCP 관리기준 수행실태 조사 - HACCP 시스템 CCP 3~CCP 7을 중심으로 -)

  • Lee, Ae-Rang
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.26 no.6
    • /
    • pp.517-530
    • /
    • 2016
  • This research was conducted on Seoul region elementary, middle, and high school nutritionists to analyze execution conditions of HACCP control standards, focusing on PHF and CCP 3~CCP 7, in order to determine more efficient methods for school meals' sanitation system settlement. All surveys were distributed and collected via email. A total of 305 survey papers were collected, and 300 school results were analyzed. The following percentage of nutritionists perceived the following foods as potentially hazardous foods(PHF): raw or cooked animal foods (94.7%), blossomed seed products (93.7%), packed pickled radish (36.7%), unopened mayonnaise (30.2%), and unopened snails & corn cans 54.8%. Exactly 51.2% of nutritionists believed that foods were properly supplied via CCP 3's food quality standard. Exactly 33.9% of nutritionists answered that they had never corrected the digital thermometer since there were no issues with the CCP 4's digital thermometer correction frequency level. As for CCP 5's chroline disinfection of green vegetables, 57.1% of nutritionists answered that vegetables were slightly softened while 36.2% said there were no changes at all. According to the nutritionists, the most difficult execution level of CCP levels (excluding CCP 3, CCP 4) was CCP 7 (37.1%), CCP 6 (16.4%), and CCP 2 (16.4%). For the above results, proper training/education must be enforced so that nutritionists can have a clear notion of the PHF. A solution must be developed enhancing the execution of CCP 4's digital thermometer correction frequency level. For CP 5's chroline disinfection of green vegetables, food characteristics must be considered to suggest an appropriate number and method of cleansing. Furthermore, cooking employees are needed that properly use and manage cooling & heating equipments to maintain heated foods above 57C under the CCP 7 standard.

The Power System for Home Appliance Air-Conditioner using Partial Switching Power Factor Correction Module (부분 스위칭 PFC 모듈을 이용한 가정용 에어컨 전원장치)

  • Suh, Ki-Young;Mun, Sang-Pil
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.18 no.6
    • /
    • pp.183-190
    • /
    • 2004
  • This paper proposes a methodology to solve problems upon the circuit design applied to inductor load by applying a circuit to improve power factor with is partial switching PFC module to the power supply system for cooling/heating inverter air conditioner and by designing an input power section in compliance with IEC555-2 on the basis of better input power factor and minimized harmonic components of current. On the other hand, this paper suggested how to control the increase of output voltage along with tぉw current waves and partial switching PFC circuit as well, which can provide the output as twice as input voltage This study applied a method to control the compressors of air conditioner by means of increased the voltage applicable to compressor motor by lowering switching number conclusively, it could solve questions about efficiency, economics, electronic noise and so forth. and so that the reasonable voltage for running moor could be set up along with lower power consumption of air conditioner than estimated It was demonstrated that total sum of energy efficiency to operate system was increased to the extent of valid level. And all this merits and appropriateness was proved by computer simulation and experience.

Development of a High Heat Load Test Facility KoHLT-1 for a Testing of Nuclear Fusion Reactor Components (핵융합로부품 시험을 위한 고열부하 시험시설 KoHLT-1 구축)

  • Bae, Young-Dug;Kim, Suk-Kwon;Lee, Dong-Won;Shin, Hee-Yun;Hong, Bong-Guen
    • Journal of the Korean Vacuum Society
    • /
    • v.18 no.4
    • /
    • pp.318-330
    • /
    • 2009
  • A high heat flux test facility using a graphite heating panel was constructed and is presently in operation at Korea Atomic Energy Research Institute, which is called KoHLT-1. Its major purpose is to carry out a thermal cycle test to verify the integrity of a HIP (hot isostatic pressing) bonded Be mockups which were fabricated for developing HIP joining technology to bond different metals, i.e., Be-to-CuCrZr and CuCrZr-to-SS316L, for the ITER (International Thermonuclear Experimental Reactor) first wall. The KoHLT-1 consists of a graphite heating panel, a box-type test chamber with water-cooling jackets, an electrical DC power supply, a water-cooling system, an evacuation system, an He gas system, and some diagnostics, which are equipped in an authorized laboratory with a special ventilation system for the Be treatment. The graphite heater is placed between two mockups, and the gap distance between the heater and the mockup is adjusted to 23mm. We designed and fabricated several graphite heating panels to have various heating areas depending on the tested mockups, and to have the electrical resistances of 0.20.5 ohms during high temperature operation. The heater is connected to an electrical DC power supply of 100 V/400 A. The heat flux is easily controlled by the pre-programmed control system which consists of a personal computer and a multi function module. The heat fluxes on the two mockups are deduced from the flow rate and the coolant inlet/out temperatures by a calorimetric method. We have carried out the thermal cycle tests of various Be mockups, and the reliability of the KoHLT-1 for long time operation at a high heat flux was verified, and its broad applicability is promising.

Field Survey on Smart Greenhouse (스마트 온실의 현장조사 분석)

  • Lee, Jong Goo;Jeong, Young Kyun;Yun, Sung Wook;Choi, Man Kwon;Kim, Hyeon Tae;Yoon, Yong Cheol
    • Journal of Bio-Environment Control
    • /
    • v.27 no.2
    • /
    • pp.166-172
    • /
    • 2018
  • This study set out to conduct a field survey with smart greenhouse-based farms in seven types to figure out the actual state of smart greenhouses distributed across the nation before selecting a system to implement an optimal greenhouse environment and doing a research on higher productivity based on data related to crop growth, development, and environment. The findings show that the farms were close to an intelligent or advanced smart farm, given the main purposes of leading cases across the smart farm types found in the field. As for the age of farmers, those who were in their forties and sixties accounted for the biggest percentage, but those who were in their fifties or younger ran 21 farms that accounted for approximately 70.0%. The biggest number of farmers had a cultivation career of ten years or less. As for the greenhouse type, the 1-2W type accounted for 50.0%, and the multispan type accounted for 80.0% at 24 farms. As for crops they cultivated, only three farms cultivated flowers with the remaining farms growing only fruit vegetables, of which the tomato and paprika accounted for approximately 63.6%. As for control systems, approximately 77.4% (24 farms) used a domestic control system. As for the control method of a control system, three farms regulated temperature and humidity only with a control panel with the remaining farms adopting a digital control method to combine a panel with a computer. There were total nine environmental factors to measure and control including temperature. While all the surveyed farms measured temperature, the number of farms installing a ventilation or air flow fan or measuring the concentration of carbon dioxide was relatively small. As for a heating system, 46.7% of the farms used an electric boiler. In addition, hot water boilers, heat pumps, and lamp oil boilers were used. As for investment into a control system, there was a difference in the investment scale among the farms from 10 million won to 100 million won. As for difficulties with greenhouse management, the farmers complained about difficulties with using a smart phone and digital control system due to their old age and the utter absence of education and materials about smart greenhouse management. Those difficulties were followed by high fees paid to a consultant and system malfunction in the order.

A Development of Automation System and a Way to use Solar Energy System Efficiently in Greenhouse(1) - Study on temperature variation of soil heating in greenhouse - (시설원예용 태양열 시스템의 효율적 이용과 자동화 장치개발(1) - 시설재배시 지중가온의 온도변화 연구 -)

  • 김진현;김철수;명병수;최중섭;구건효;김태욱
    • Journal of Bio-Environment Control
    • /
    • v.7 no.1
    • /
    • pp.15-24
    • /
    • 1998
  • The greenhouse temperature controls in general have been managed by the above-ground part environment, But the temperature of root zone was known very important factor for the 9rofth and the yield of vegetables in greenhouse. The purpose of this study is to develop a good method for cultivation using solar energy which can apply warming soil and to develop the greenhouse soil temperature automatic control system. Followings are summary of this study:1 When the greenhouse inner temperature changes were about 24C during a day in October, the temperature of non-warmed soil was differenced 6C in the depth 10cm and 3C in the depth 20cm. 2. When water supply temperature was kept at 40, 50 and 60C, the lowest soil temperature in the depth of 10cm is 20C and that of 20cm was 23C. and when the water supply temperature was over 40C, the space heating temperature did not affect the temperature variation of soil. 3. In comparison with conditions of the warmed and non-warmed soil, when the water supply temperature is 28C, soil temperatures had the high temperature of 40C~7C in the depth of 10cm to 20 cm. 4. The line of boundary area was appeared in the depth of 15~20cm, 13~19cm and 12~17cm. when the water supply temperature was 40C, 50C and 60C. 5. When th inner greenhouse air temperature is maintained over 11C and the water supply temperature is supported 28C, the lowest temperature is kept up over 20C.

  • PDF

A Study on the Integrated Fusion Technology Between a Carbon Dioxide Emission and a District Cooling Energy Using a Cold Energy (CO2 배출문제와 냉열이용 지역집단 냉방에너지에 관한 통합적 융합기술 연구)

  • Kim, Chung-Kyun
    • Journal of the Korean Institute of Gas
    • /
    • v.10 no.4 s.33
    • /
    • pp.34-40
    • /
    • 2006
  • This paper provides a fusion technology between a district cooling energy system and an environment conservation policy based on the energy savings and reusable cold energy resources. The district heating and cooling systems are very effective ways for an energy saving, a cost reduction and a safety control. It is necessary to equalize the energy savings and an environmental preservation policy for an improved human lift. A gasification process of a liquefied natural gas, cooling water from deep seawater and an ice water thermal storage system may produce a cold energy. A district cooling system is used to cool an apartment, office buildings and factory facilities with a cooling energy supply pipeline. LNG cooling energy will switch a conventional air-conditioning system, which is operated by on electrical energy and a Freon refrigerant. Coincident with significant clean energy and operating cost savings, LNG cold energy system owen radical reductions in an air-borne pollutant, CO2 and the release of environmentally harmful refrigerants compared with that of the conventional air-conditioning system. This study provides useful information on the fusion technology of a LNG cold energy usage and energy savings, and environmental conservation.

  • PDF

An Operation Status Analysis of Library Building using BEMS Data; Energy Performance Evaluation on Initial Stage of Completion (BEMS 데이터를 활용한 도서관 건물의 운전현황 분석 -준공 초기단계의 건물 에너지 성능 평가)

  • Park, Seong-cheol;Ha, Ju-wan;Kim, Hwan-yong;Song, Young-hak
    • Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
    • /
    • v.12 no.6
    • /
    • pp.669-679
    • /
    • 2018
  • Energy consumption savings in buildings should be reviewed in diverse areas such as air conditioning system and lighting responsible for cooling and heating, and energy management systems such as BAS (Building Automation System) and BEMS (Building Energy Management System) are introduced to improve energy consumption efficiency and to promote economic control of related facilities by integrated management of energy generated and consumption in buildings. The measured building of this study uses regenerative geothermal system. Measured values of heat pump and system COP were 4.7 and 4.2 respectively, and they were found to be higher 11.9% and 23.5% than rated values. As a result of analyzing the air conditioning and lighting energy from the first floor to the fourth floor performing the air conditioning, the second and third floors, which have a high frequency of use, are compared with the first and fourth floors 50% higher energy consumption ratio. On the other hand, the general heat storage system uses the nighttime power of the previous day to store heat and use it the next day. The total number of days of abnormal operation during the summer season is 61 days. The electricity cost corresponding to the abnormal operation is 1,840,641 KRW, and the normal operation using the nighttime power is 1,363,561 KRW, which is difference of 477,080 KRW, 35% increase in cost. We will utilize it as the main data of BEMS through analysis of winter operation characteristics as well as summer operation characteristics.

The Design of High efficiency multi-channel LED light Driver suitable for Streetlamp (가로등에 적합한 고효율 멀티채널 LED 조명 구동장치 설계)

  • Song, Je-Ho;Kim, Hwan-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.15 no.7
    • /
    • pp.4489-4493
    • /
    • 2014
  • LED light driving device has problems in efficiency and heating at higher than 150W. In addition, there is inconvenience in replacing the lighting device to another when W is not the same as the previous one. In this paper, a multi-channel LED light driver, driver embedded driver circuit in a multi-channel structure with a power system in the driver-interlocking structure was designed. With the auto control converter structure with a power efficiency above 93% and power factor above 0.98, the weight of the high efficiency LED lighting-actuating device in driver-interlocking structure, a driver in self-calibrating self-optimization structure. In this paper, at below 10% THD, the existing converter contrast weight was reduced by 40% or more.

Design of a Neuro Observer for Reduction of Estimate Error (추정오차 저감을 위한 뉴로 관측기 설계)

  • Yoon, Kwang-Ho;Kim, Sang-Hoon;Ban, Gi-Jong;Choi, Sung-Dae;Park, Jin-Su;Kim, Lark-Kyo;Nam, Moon-Hyon
    • Proceedings of the KIEE Conference
    • /
    • 2004.11c
    • /
    • pp.693-695
    • /
    • 2004
  • Among modem control method, the observer is being used widely because it has the advantage of the guarantee of reliability on financial problem, over heating, and physical shock. However, an existing state observer and a sliding observer have such problems that an experimenter needs to know dynamics and parameters of the system. And also, the high gain observer has such a problem that it has transient state at the beginning of the observation. In this paper, the neuro observer is proposed to improve these problems. The proposed observer complement a problem that occur from increase of gain of High-gain observer in proportion to the square number of observable state variables. And also, the proposed observer can tune the gain obtained by differentiating observational error at transient state automatically by using the backpropagation training method to stabilize the observational speed. To prove a performance of the proposed observer, it is simulated that the comparison between the state estimate performance of the proposed observer and that of sliding, high gain observer is made by using a sinusoidal input to the observer which consists of four layers in stable 2nd order system.

  • PDF

An Experimental Study of Petroleum Cokes Air Staged Burner (공기다단 적용 석유코크스 연료 전용 연소기에 대한 실험적 연구)

  • Kwon, Minjun;Lee, Changyeop;Kim, Sewon
    • Journal of the Korean Society of Combustion
    • /
    • v.20 no.2
    • /
    • pp.40-45
    • /
    • 2015
  • This study is aimed to study combustion characteristics of low NOX burner using petroleum cokes as fuel. The petroleum coke, which is produced through the oil refining process, is an attractive fuel in terms of its high heating value and relatively low price. But petroleum coke is a challenging fuel because of its low volatile content, high sulfur and nitrogen content, which give rise to undesirable emission characteristics and low ignitability. The petroleum cokes burner is operated at fuel rich condition, and overfire air are supplied to achieve fuel lean condition. The low NOX burner is designed to control fuel and air mixing to achieve air staged combustion, in addition secondary and tertiary air are supplied through swirler. Air distribution ratio of triple staged air are optimized experimentally. The result showed that NOX concentration is lowest when overfire air is used, and the burner function at a fuel rich condition.