INFLUENCE OF DEPOSITION AND FOULING ON WALL TEMPERATURE DISTRIBUTION IN CONVECTIVE PATH

2020 ◽  
pp. 1-21
Author(s):  
Deli Li ◽  
Enlu Wang ◽  
Jinda Mao ◽  
Wei Wu ◽  
Yiyang Wang

Abstract To develop a method of controlling the deposit tube surface temperature, the rules of deposition and fouling on the fireside, and the influence factors of the surface distribution were determined through experiments and theoretical calculations. The surface temperature distribution of a clean tube was compared with that of a deposit tube. Through theoretical calculations, the influence factors of the deposit tube surface temperature were evaluated. Based on the investigation, surface temperature control technology applicable to a super-heater was proposed and the feasibility of this heater was determined. A bimodal distribution was obtained when the temperature distribution of the deposit tube was plotted as a function of the angle, whereas a unimodal distribution was obtained for the clean tube. The results revealed that the heat exchange tube surface temperature is most effectively controlled by controlling the flue gas temperature. Prior to the development of higher performance materials (compared with conventional materials), surface temperature control technology can be used to ensure that the super-heater surface temperature lies below the allowable temperature of existing super-heater materials.

Author(s):  
Anna Lubkowska ◽  
Monika Chudecka

Thermography is widely used in the medical field, including in the detection of breast disorders. The aim of the research was to characterize the range of breast surface temperature values, taking into account the entire area of the mammary gland and, independently, the nipple, in healthy women. An additional aim was to assess the symmetry of the breast temperature distribution (using an IR camera) and the correlation of temperatures with the content of adipose tissue. Thermograms were made for the right and left breasts, each time delineating the area of the entire breast and a separate area of the nipple, chest, and abdomen. Analyzing the intergroup differences in temperature of selected body areas (Tmean), it was shown that, in all cases, they were significantly higher in younger women. Statistical analysis showed no significant differences between breast and nipple temperatures in relation to the body sides. The highest temperatures within the mammary gland were recorded for the nipple area. The use of the high-resolution digital infrared thermal imaging method in early and screening preventive diagnoses of changes in the mammary gland requires individual interpretation of the results, taking into account the assessment of the physiological pattern of temperature distribution in both breasts.


Author(s):  
Junnosuke Okajima ◽  
Atsuki Komiya ◽  
Shigenao Maruyama

The objective of this work is to experimentally and numerically evaluate small-scale cryosurgery using an ultrafine cryoprobe. The outer diameter (OD) of the cryoprobe was 550 μm. The cooling performance of the cryoprobe was tested with a freezing experiment using hydrogel at 37 °C. As a result of 1 min of cooling, the surface temperature of the cryoprobe reached −35 °C and the radius of the frozen region was 2 mm. To evaluate the temperature distribution, a numerical simulation was conducted. The temperature distribution in the frozen region and the heat transfer coefficient was discussed.


2010 ◽  
Vol 375 (2) ◽  
pp. 165-169 ◽  
Author(s):  
Ken-ichi Amano ◽  
Daisuke Miyazaki ◽  
Liew Fong Fong ◽  
Paul Hilscher ◽  
Taro Sonobe

Author(s):  
Tang Chian-ti

Taking account of the marine gas turbine operation features, the author has chosen the hot corrosion peak temperature of materials as the guide vane material limiting temperature while evaluating the overall temperature distribution factor. Along with the blade cooling effectiveness a safety margin factor has been introduced during its evaluation. The gas temperature distribution along blade height is assumed to satisfy the condition that approximately equal safety factor in respect of strength prevails along blade height. Once the gas radial temperature profile becomes known, the radial temperature distribution factor can be readily determined.


2005 ◽  
Vol 4 (1) ◽  
pp. 3-7 ◽  
Author(s):  
Peter D. Ditlevsen

The mean surface temperature on Earth and other planets with atmospheres is determined by the radiative balance between the non-reflected incoming solar radiation and the outgoing long-wave black-body radiation from the atmosphere. The surface temperature is higher than the black-body temperature due to the greenhouse warming. Balancing the ice-albedo cooling and the greenhouse warming gives rise to two stable climate states. A cold climate state with a completely ice-covered planet, called Snowball Earth, and a warm state similar to our present climate where greenhouse warming prevents the total glaciation. The warm state has dominated Earth in most of its geological history despite a 30% fainter young Sun. The warming could have been controlled by a greenhouse thermostat operating by the temperature control of the weathering process depleting CO2 from the atmosphere. This temperature control has permitted life to evolve as early as the end of the heavy bombardment 4 billion years ago.


2010 ◽  
Vol 67 (5) ◽  
pp. 497-502 ◽  
Author(s):  
Irenilza de Alencar Nääs ◽  
Carlos Eduardo Bites Romanini ◽  
Diego Pereira Neves ◽  
Guilherme Rodrigues do Nascimento ◽  
Rimena do Amaral Vercellino

Broiler chickens in Brazil are generally reared from 1 to 42 days when they are exposed to procedures such as fasting, harvesting, crating and transport to slaughter. Maintaining homeostasis is of great importance for broiler survival under harsh environment especially prior to slaughter. Heat loss varies in the distinct parts of the body during the growth period, and it is related to the air temperature of the environment and to the amount of feather covering. This research aimed to study the surface temperature distribution using infrared thermographic image processing to characterize 42 day old broiler chicken surface temperature prior to slaughter. Broilers were reared for 42 days and prior to harvest and transport to slaughter the infrared surface temperature was recorded along the day. Data from the thermograms taken in feather and featherless regions were compared during the 42nd day of growth. High correlation between featherless regions and air temperature was found showing that these areas respond fast to changes in the rearing environment. Two functions were developed for predicting both surface temperature for featherless and feather covered areas of the broiler body parts.


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