• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집A
• /
• pp.914-919
• /
• 2000

In most case high temperature components in fossil power plant are damaged by fatigue, creep and degradation. Design of power plant components is based on ideal loading such as temperature, pressure and so on. But in many cases unexpected loadings are applied at components. A key ingredient in plant life extension is the preventive diagnosis technology and remaining-life-assessment technology. This paper describes diagnosis technology and life-assessment technology for power plant boiler. It helps in setting up proper inspection schedules, maintenance procedures, and operating procedure.

• 플랜트 저널
• /
• 제14권1호
• /
• pp.42-46
• /
• 2018

The flow and heat transfer characteristics inside a solar chimney power plant system are analyzed in this article. 3-D model with the $k-{\varepsilon}$ turbulence closure was developed. In this model, to solve the radiative transfer equation the discrete ordinates radiation model was implemented, using a two-band radiation model. To simulate radiation effects from the sun's rays, the solar ray tracing algorithm was coupled to the calculation via a source term in the energy equation. Simulations were carried out for a system with the geometry parameters of the Manzanares power plant. Based on the numerical results, the velocity and temperature distributions were illustrated and the results were validated by comparing with experimental data of the Manzanares prototype power plant. Moreover, temperature profile of the ground surface of the system was illustrated.

• 한국태양에너지학회 논문집
• /
• 제36권2호
• /
• pp.1-7
• /
• 2016

This study was experimentally performed to analyze the growth characteristics of a plant(wax tree or privet) using the surface temperature measured from thermal images captured using a thermal camera with water and cider. To do that, this study measured every each 12 hours the surface temperature and the stem temperature of leaves attached to the plant sample until the plants wilt on summer season in the laboratory room. From the experimental results, this study revealed that the temperature of front and back of the leaves is a little different due to the pore. The mean surface temperature of a leaf in cider is $0.52^{\circ}C$ higher than that of a leaf in water. The phenomena that the leaves of plants fall could be also demonstrated using the surface temperature. Before a leaf is falling from the tree, the temperature of the stem is lowered about $2^{\circ}C$ than those of other parts in a leaf. This result can be validated from previous result performed in University of Wisconsin.

• Journal of Ecology and Environment
• /
• 제46권3호
• /
• pp.161-171
• /
• 2022

Background: Epilobium hirsutum L. is designated as an endangered plant in South Korea located in Asia, due to the destruction of its habitats through the development of wetlands. Therefore, in this study, in order to find a light condition suitable for the growth and ecophysiological responses of Epilobium hirsutum L., those of this plant under treatment with various light qualities in a smart farm were measured. Results: In order to examine the changes in the physiological and growth responses of Epilobium hirsutum L. according to the light qualities, the treatment with light qualities of the smart farm was carried out using the red light: blue light irradiation time ratios of 1:1, 1:1/2, and 1:1/5 and a red light: blue light: white light irradiation time ratio of 1:1:1. As a result, the ecophysiological responses (difference between leaf temperature and atmospheric temperature, transpiration rate, net photosynthetic rate, intercellular CO₂ partial pressure, photosynthetic quantum efficiency) to light qualities appeared differently according to the treatments with light qualities. The increase in the blue light ratio increased the difference between the leaf temperature and the atmospheric temperature and the photosynthetic quantum efficiency and decreased the transpiration rate and the intercellular CO₂ partial pressure. On the other hand, the white light treatment increased the transpiration rate and intercellular CO₂ partial pressure and decreased the temperature difference between the leaf temperature and the ambient temperature and photosynthetic quantum efficiency. Conclusions: The light condition suitable for the propagation by the stolons, which are the propagules of Epilobium hirsutum L., in the smart farm, is red, blue and white mixed light with high net photosynthetic rates and low difference between leaf temperature and atmospheric temperature.

• 환경위생공학
• /
• 제22권1호
• /
• pp.1-16
• /
• 2007

The incineration process has commonly used for wastes amount reduction and thermal treatments of pollutants as the technologies accumulated. However, the process is getting negative public images owing to matter of hazardous pollutants emission. Specially dioxins became a main issue and is mostly emitted from municipal solid wastes incineration. In this reason, pyrolysis/gasfication/melting process is presented as a alternative of incineration process. The pyrolysis/gasfication/melting process, a novel technology, is middle of verification of commercial plant and development of technologies in Korea. But the survey about the pollutant emission from the process, and background data in these facilities is necessary. So in this survey, it Is investigated that the behavior of dioxins in three pyrolysis/gasfication/melting plant (S, T, P) of pilot scale. In case of S plant, concentration of dioxins shows high at latter part of cogenerated boiler and stack which are operate on low temperature conditions than a latter parts of pyrolysis and melting furnace which are operate on high temperature condition. Concentration of gas phage dioxins had increased after combusted gas passed cogenerated boiler and this is attributed to react of precursor materials such as chlorobenzene and chlorophenol. Concentration of dioxins in T plant showed lower levels at latter part of cooling equipment which are operate with water spray type on low temperature conditions than a latter parts of gasfied melting furnace which are operate on high temperature condition. Removal efficiency of dioxins at gas treatment equipment was 78.8 %. Concentration of dioxins in P plant was low at latter part of SDA/BF which is operate at low temperature conditions than a latter parts of pyrolysis gasfied chamber which are operate at high temperature condition. Removal efficiency of dioxins of SDA/BF was 85.9 % and therefore, it showed high efficiency at those of stoker type incineration facility. However, concentration of dioxins which emitted at high temperature condition were low in three facilities and satisfied present standard emission level of dioxins. To consider the distribution ratio of dioxins, Particulate phase dioxins at S and P plants showed similar ratio with which shows in current stoker type for middle scale domestic waste incineration facility. It is necessary to continuos monitoring the ratio of distribution of dioxins in T plant in because ratio of gas phage dioxins showed high.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.129-133
• /
• 2005

In this paper, first the thermodynamic model is presented to one of the super heaters and sprays of the Nekka power plant and then its unknown parameters are identified according to the registered data of the power plant. SCO control method is introduced to control the external steam temperature of super heater. Finally the conventional method in power plant for controlling external steam temperature of super heater is compared with new method and their performances are presented..

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 하계학술대회 논문집 B
• /
• pp.673-675
• /
• 1995

A nonlinear process-model based control for main steam temperature control of a 100MW oil-fired drum-type fossil power plant is delveloped and its performances are compared to those of the conventional PID control. The process model for simulation is derived based "first priciple approach" and is validated in steady and transient conditions. The model is in good agreements with the field test data. Performances of the nonlinear PMBC for main steam temperature control are far superior to those of PID in all aspects for the disturbances of ramp increase in load and step change in fuel Btu value.

• Nuclear Engineering and Technology
• /
• 제48권6호
• /
• pp.1404-1411
• /
• 2016

Pipe wall thinning in the secondary piping system of a nuclear power plant is currently a major problem that typically affects the safety and reliability of the nuclear power plant directly. Regular in-service inspections are carried out to manage the piping system only during the overhaul. Online thickness monitoring is necessary to avoid abrupt breakage due to wall thinning. To this end, a transducer that can withstand a high-temperature environment and should be installed under the insulation layer. We propose a thin plate type of embedded ultrasonic transducer based on magnetostriction. The transducer was designed and fabricated to measure the thickness of a pipe under a high-temperature condition. A number of experimental results confirmed the validity of the present transducer.

• 한국정밀공학회지
• /
• 제22권6호
• /
• pp.83-89
• /
• 2005

Most domestic fossil power plants have exceeded 100,000 hours of operation with the severe operating condition. Among the critical components of fossil power plant, high temperature steam pipe systems have had a many problems and damage from unstable displacement behavior because of frequent start up and shut down. In order to prevent the serious damage and failure of the critical pipe system in fossil power plants, 3-dimensional displacement measurement system was developed for the on-line monitoring. Displacement measurement system was developed with a use of a LVDT type sensor and two rotary encoder type sensors. This system was installed and operated on the real power plant successfully.

• The Plant Pathology Journal
• /
• 제34권4호
• /
• pp.316-326
• /
• 2018

The effect of simulated climate changes by applying different temperatures and $CO_2$ levels was investigated in the Blumeria graminis f. sp. tritici/wheat pathosystem. Healthy and inoculated plants were exposed in single phytotrons to six $CO_2$+temperature combinations: (1) 450 ppm $CO_2/18-22^{\circ}C$ (ambient $CO_2$ and low temperature), (2) 850 ppm $CO_2/18-22^{\circ}C$ (elevated $CO_2$ and low temperature), (3) 450 ppm $CO_2/22-26^{\circ}C$ (ambient $CO_2$ and medium temperature), (4) 850 ppm $CO_2/22-26^{\circ}C$ (elevated $CO_2$ and medium temperature), (5) 450 ppm $CO_2/26-30^{\circ}C$ (ambient $CO_2$ and high temperature), and (6) 850 ppm $CO_2/26-30^{\circ}C$ (elevated $CO_2$ and high temperature). Powdery mildew disease index, fungal DNA quantity, plant death incidence, plant expression of pathogenesis-related (PR) genes, plant growth parameters, carbohydrate and chlorophyll content were evaluated. Both $CO_2$ and temperature, and their interaction significantly influenced powdery mildew development. The most advantageous conditions for the progress of powdery mildew on wheat were low temperature and ambient $CO_2$. High temperatures inhibited pathogen growth independent of $CO_2$ conditions, and no typical powdery mildew symptoms were observed. Elevated $CO_2$ did not stimulate powdery mildew development, but was detrimental for plant vitality. Similar abundance of three PR transcripts was found, and the level of their expression was different between six phytotron conditions. Real time PCR quantification of Bgt was in line with the disease index results, but this technique succeeded to detect the pathogen also in asymptomatic plants. Overall, future global warming scenarios may limit the development of powdery mildew on wheat in Mediterranean area, unless the pathogen will adapt to higher temperatures.