• 한국염색가공학회지
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• 제18권6호
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• pp.69-79
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• 2006

The washing characteristics of steam jet heating process have been compared with other washing processes, such as low temperature process(standard process, below $40^{\circ}C$) and high temperature process(boiling process, up to $95^{\circ}C$) with the standard soil fabric, EPMA 105. Steam jet heating process showed almost the same washing efficiency as high maximum temperature process for pig's blood and wine. This result can be explained with the higher surface temperature of washing materials in steam jet process compared with direct boiling process. In terms of the energy and water consumption, the steam jet washing process showed significant savings compared with direct boiling type washing process.

• Journal of the Korean Wood Science and Technology
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• 제35권5호
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• pp.1-6
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• 2007

Boiling-in-oil process was performed to investigate the high-temperature drying characteristics of 25, 50, and 70 mm-thick flat-sawn Douglas-fir lumber. Drying rates, moisture profiles and temperature profiles were monitored. Fully refined paraffin wax was used as drying agent and heated to $130^{\circ}C$. Average drying rates of 25, 50, and 70 mm-thick specimen were 11.6, 6.7, 5.0%/h, respectively. The moisture content differences between cores and ends were 1~2% in 25 mm-thick and 200 mm-long sample and over 10% in 50 mm-thick and 600 mm-long sample.

• Journal of Advanced Marine Engineering and Technology
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• 제17권2호
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• pp.36-43
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• 1993

Real quality and axial void fraction distribution of subcooled refrigerant flow is very important to predict the heat transfer rate and pressure drop in the design of refrigerating system. In the subcooled boiling region, the liquid bulk temperature is still below the corresponding saturation temperature. But beyond the net vapor generation point, bubble detachment is occured actively from the vapor layer formed on the wall. A reliable method to predict the vapor fraction from the liquid bulk temperature is suggested in this paper. And also the actual quality of the subcooled R-113 flow is calculated in the range of 261-1239kg/$m^2$s mass velocity and 10-30K subcooling.

• 한국식품조리과학회지
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• 제15권5호
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• pp.490-499
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• 1999

한우암소의 양지머리(brisket)와 사골(shank)을 전처리 방법, 가열 온도 및 시간에 따른 곰국의 맛성분 변화를 연구하기 위하여 유리아미노산과 핵산관련물질을 분석하고 색도 측정과 관능평가를 병행한 결과를 다음과 같이 요약할 수 있었다. 1. Soaking, blanching 전처리 양지머리 곰국의 유리아미노산 용출량은 대체로 가열시간에 따라 증가하는 경향이었으며 용출량은 고온가결 보다 저온가열시에 많았으나 roasting 전처리 곰국은 고온 가열시의 용출량이 높았다. Glutamic acid 용출량은 대체로 soaking＞blanching> roasting의 순으로 많았으며 저온에서 6시간 가열시료 (BSL)의 용출량이 8.73 mg%로 가장 많았고 1시간 가열시의 17배 정도였다. 2. 사골(shank) 곰국 중의 유리아미노산 용출량은 전처리법에 따른 일정한 경향이 없었으며 용출량도 매우 적었다. Glutamic acid 용출량은 저온가열시에는 일정한 경향은 볼 수 없었으나 soaking, blanching 전처리하여 고온가열 3시간 시료에서, roasting처리하여 고온 가열 6시간 시료가 2.49 mg%로 최고치를 보였다. 3. 양지머리 곰국 중 핵산관련 물질의 용출량은 대체로 가열에 따라 증가하는 경향이었다. Soaking, blanching 전처리하여 저온가열 한 시료의 5'-IMP 용출량은 6시간 가열한 시료(BSL)가 37.06%, 5 시간 가열한 시료(BBL)이 38.37 mg%로 최고치를 보였으며 roasting 전처리하여 고온가열 6시간 시료(BRH)가 10.85 mg%로 최고치를 보였다. 4. 사골곰국의 5'-IMP 용출량은 soaking＞blanching>roasting 전처리 순으로 많이 용출 되었으며 대체로 고온 가열시 높은 용출량을 보였으며 soaking, blanching 전처리시료는 가열 온도와 관계 없이 3시간 가열 이후 부터는 감소하는 경향이었다. Roasting 처리하여 고온가열 6시간 시료의 5'-IMP 용출량은 1.55 mg%로 최고치를 보였다. 5. Roasting 전처리 고온가열 양지머리 곰국(BRH)의 색차계에 의한 L값은 가장 낮았으며 b값은 가장 높은 값을 보였으나 사골곰국의 L, a, b 값은 전처리 방법이나 가열 온도에 따른 차이는 크지 않았다. 6. 양지머리 곰국의 색ㆍ향에 대한 관능평가는 roasting 전처리 고온가열시료(BRH)의 선호도가 가장 높았으며 맛 전반적 기호에 대한 선호도는 soaking 전처리 고온가열시료(BSH)가 가장 높았으며, 사골곰국의 경우에는 soaking 전처리 고온가열시료(SSH)의 모든 관능적 특성의 선호도가 가장 높았다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.671-676
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• 2001

This study are development results of solar hot water system for anchovy proceeding. The heat amounts of boiling vessel are calculated 292.66W at forward and backward direction, and surface direction are calculated 373.14W. The polyenoic rate of anchovy are measured lower as high temperature, but monoenoic and polyacid are higher. Then the others. The maximum radiation of anchovy fishing grounds are shown $350kcal/m^2h$ at pm. 13:00, Chungdo in CHINA. Distributions of Velocity and temperature in boiling vessel are calculation. Solar collector and boiling vessel for anchovy proceeding ship are developed to automatic control system.

• 한국분무공학회지
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• 제27권1호
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• pp.42-49
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• 2022

Flash boiling occurs in a couple of modern engineering systems and understanding its mechanism is important. In this experimental study, discharge coefficient of flash boiling spray from simple orifice nozzle was measured, and backlight imaging was acquired at injection pressure to 6.0 bar and temperature to 163℃ for the purpose. Pressurized water by pump was used for working fluid and was heated by electric heater and ejected through simple orifice nozzle diameter of 0.5 mm. High speed camera with long distance microscope was used for backlight imaging in two FoV having magnification of 3.3 and 0.64. The decrease of discharge coefficient according to degree of superheating and evolution of flash boiling spray imaged at various pressure and temperature were explained by the pressure field inside the injector.

• 한국분무공학회지
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• 제28권2호
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• pp.89-96
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• 2023

This study presents a numerical simulation investigating hydrodynamic characteristics of high-temperature hydrocarbon aviation fuel injected through a plain orifice injector. The analysis encompassed the temperature range up to the critical point, and the obtained results were compared with prior experimental observations. The analysis unveiled that the injector's exit pressure remains equivalent to the ambient pressure when the fuel injection temperature is below the boiling point. However, when the fuel temperature surpasses the boiling point, the exit pressure of the injector transitions to the saturated vapor pressure corresponding to the fuel injection temperature. Consequently, the exit pressure of the injector increases in tandem with the rapid increase of the saturation vapor pressure due to escalating fuel temperatures. This rise in the exit pressure necessitates a proportional increase in fuel injection pressure to ensure a fixed fuel mass flow rate. Furthermore, the investigation revealed that the discharge coefficient obtained by applying the exit pressure instead of the ambient pressure did exhibit no decrease, but rather was maintained at a nearly constant value, comparable to its level below the boiling point.

• 에너지공학
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• 제15권1호
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• pp.35-44
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• 2006

본 연구에서는 비등열전달 과정동안, 초음파 진동이 열전달 과정에 미치는 영향에 관하여 실험적으로 조사해 보았다. 실험은 등온가열조건하에서, 40kHz의 초음파 진동을 가진한 경우와 가진하지 않은 경우로 나누어 비등과정동안의 온도분포를 측정하였고, 대류상태와 과냉상태 그리고 포화상태에서의 열전달계수를 측정하여 열전달 향상율을 비교하여 보았다. 또한, 하이드로폰을 이용하여 초음파 가진시 매질내에 발생하는 음압분포를 측정하고 열전달 향상율과 비교하여 보았다. 실험결과, 비등열전달 과정에 초음파 진동을 가진한 경우, 가진하지 않은 경우와 비교하였을 때 열전달계수가 높게 나타나는 것을 확인하였으며, 특히 대류상태에서 열전달계수가 급격하게 증가하였다. 또한, 초음파 진동의 가진으로 인해 형성되는 음압은 진동자가 부착된 지점에서 주위보다 상대적으로 높게 형성되는 것을 실험적으로 확인하였으며, 초음파 진동으로 인해 형성된 높은 음압이 열전달 향상율에 영향을 미치는 원인의 하나로 작용하고 있음을 알 수 있었다. 결국, 초음파 진동에 의해 매질내에 발생하는 음압은 열전달 향상과 밀접한 관련이 있다고 사료된다.

• Journal of Advanced Marine Engineering and Technology
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• 제22권6호
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• pp.880-887
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• 1998

In order to study heat transfer characteristics of spray cooling for the purpose of uniform and soft cooling of high temperature surface a series of experiments for a hot horizontal copper flat plate was performed by downflow spray water using flat spray nozzle. Cooling curves were mea-sured under the various experimental conditions of flow rates and temperatures of cooling water Surface temperature surface heat fluxes and heat transfer coefficients of horizontal upward-facing flat surface were calculated with cooling curves measured at each radial positions near the cooling surface by TDMA method. Generally heat transfer characteristics for spray cooling is simi-lar to boiling phenomenon of pool boiling. The minimum heat flux(MHF) appear at the surface temperature of about ${\Delta}Tsat=250^{\circ}C$ and the critical heat flux(CHF) appear at about ${\Delta}Tsat=250^{\circ}C$.

• 한국분무공학회지
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• 제20권4호
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• pp.236-240
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• 2015

This study aims to experimentally investigate the evaporation characteristics of nanofluid droplet on heated surface at boiling temperature of DI-water. In particular, textured surface was used to examine the effect of wettability on evaporation. At the initial stage of evaporation process, dynamic contact angle (DCA) of nanofluid droplet with 0.01 vol.% concentration on textured surface rapidly increased over its equilibrium contact angle by generated large bubble inside the droplet due to lower wettability. However, contact angle of nanofluid droplet with higher concentration on textured surface decreased with surface tension. In addition, total evaporation time of droplet on textured surface was considerably delayed due to reduction of contact area between droplet and solid surface. Thus, evaporation characteristics were highly affected by the nanofluid concentration and surface wettability.