• Journal of Welding and Joining
• /
• v.20 no.1
• /
• pp.69-75
• /
• 2002

This study investigated the effect of the system parameters on penetration depth measurement using infrared temperature sensing system. The distance from focusing lens to detector was varied to diminish the error in measuring weld bead width. The effect of bead surface shape on measured surface temperature profile was evaluated using specimen heated by electric resistance. The measuring distance from laser beam was changed to optimize the measuring point. The results indicated that the monitoring device of surface temperature using infrared detector array was applicable to real time penetration depth control.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.1937-1941
• /
• 2007

During a process of a nanoimprint for manufacturing LCD, a small temperature variation on the LCD glass can cause thermal stress and generate unexpected displacement. To avoid this trouble, a precision temperature control unit using thermoelectric modules is appropriate for nanoimprint processes. The unit consists of an air control system, a cooling water control system, and a power control system. The air control system includes a thermoelectric module, thermocouples measuring temperatures of air and a duct-stale fin, and two air fans. The heat generated by the thermoelectric module is absorbed by the cooling water control system. The power control system catches the temperature of the thermoelectric module, and a PID controller with SCR controls the input power of the thermoelectric module. Temperature control performance is evaluated by experiment and simulation. The temperature control unit is able to control the exit temperature about ${\pm}2^{\circ}C$ from the incoming fluid temperature, and the error range is ${\pm}0.1^{\circ}C$. However, the control time is approximately 30minute, which needs further study of active control

• 한국태양에너지학회:학술대회논문집
• /
• 2012.03a
• /
• pp.165-170
• /
• 2012

This study aims to analyze the characteristics of temperature variation of Spandrels. According to the change of SHGC of Window system, air space, insulation performance and absorption factor of inner surface at the Spandrels, It was firstly estimated by using simulation. Secondly, measured to minimize the temperature-rise of inner surface temperature and the intermediate air temperature by using Full-scale Mock-up based on the result of simulation analysis. As a result, it turns out that low SHGC window system such as BIPV system had an advantage of reducing the window surface temperature, and the surface temperature of clear window system was all higher than BIPV system on simulation results. In the experiment results, it had some advantages of increasing the Spandrels volume, decreasing insulation performance and lower absorption factor.

• Nuclear Engineering and Technology
• /
• v.54 no.6
• /
• pp.2048-2054
• /
• 2022

The coolant temperature feedback coefficient is an important parameter of reactor core power control system. To study the coolant temperature feedback coefficient influence on the core power control system of small PWR, the core power control system is built with the nonlinear model and fuzzy control theory. Then, the uncertainty quantification method of reactor core parameters is established based on the Latin hypercube sampling method and the Bootstrap method. Finally, under the conditions of reactivity step perturbation and coolant inlet temperature step perturbation, uncertainty analysis for two cases is carried out. The result shows that with fuzzy controller and fuzzy PID controller, the uncertainty of the coolant temperature feedback coefficient affects the core power control system, and the maximum uncertainties of core relative power, coolant temperature deviation, fuel temperature deviation and total reactivity are acceptable.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.2
• /
• pp.147-154
• /
• 2015

In this paper, we propose human detection and fuzzy temperature control system for energy reduction of cooling device in elevator. In order to improve problems of existing cooling device using the refrigerant, energy reduction and efficient management are continuously achieved because of operation of thermoelectric cooling device using the human detection and fuzzy temperature control system. The proposed system confirms the number of passengers in elevator and temperature is then controlled by those numbers and an average temperature for the season in fuzzy system. The human detection method scans the number of passengers using a head part as a feature based on bird's-eye view camera in elevator. The fuzzy system determines elevator internal temperature considering atmospheric temperature and the scanned passenger numbers as a look-up table. The proposed system reduces energy of the cooling device through the human detection and temperature control. In experiment, energy reduction is confirmed and the performance of the proposed system is verified.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.10a
• /
• pp.371-374
• /
• 2009

This paper presents a cooling system using thermoelectron for improving the output of BIPV module. The temperature characteristic in regard to improving the output of BIPV system has rarely been studied up to now but some researchers only presented the method using a ventilator. The cooling system efficiency of BIPV module applied to a ventilator mainly depends on the weather such as wind, insolation etc. Because the cooling system of BIPV module using a ventilator is so sensitive, that is being set off by wind speed at all time but is unable to operate in the NOCT(Nominal Operating Cell Temperature) which is able to make the maximum output The paper presents the cooling system using thermoelectron so as to solve such problems. The temperature control of thermoelectron can be controlled independently in the outside environment because that is performed by micro-controller. The temperature control of thermoelectron, also, can be operated around NOCT through algorism of the temperature control. Therefore, outputs of the whole system increase and the efficiency rises. The paper demonstrates the validity of proposed method by comparing the data obtained through a experiment of the cooling method of BIPV using a ventilator and proposed thermoelectron.

• Journal of Fisheries and Marine Sciences Education
• /
• v.22 no.4
• /
• pp.604-610
• /
• 2010

Busan subway transportation system has been established a key role in the society last 20 years. However many people are suffering from hot and humid environment at subway station and platform due to deteriorated ventilation system as well as insufficient air conditioning system in existing stations and platforms. As a result, these systems require revitalization. There is about 5400tons of low temperature underground water is generated from subway stations every day. By using this method and air washer we are trying to lower the temperature. Air washer is commonly used for removing humidity but in this experiment it will be used as air precooling. This research offers result of experiment using air washer system to lower the temperature in large spaces like subway station. The experiment result has shown when L/G was the same, at condition which water spray temperature at $18^{\circ}C$ resulting inlet and outlet temperature difference larger. Also, in the same water spray temperature conditions, larger L/G condition showed a greater temperature difference. LCC evaluation of both system were shown that air washer system of using underground water will save 53% of the initial cost than refrigeration system, and save 75% of operating cost.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.27 no.10
• /
• pp.497-505
• /
• 2015

The evaporating temperature range required for the low temperature freezing system is from $-50^{\circ}C$ to $-30^{\circ}C$. Since it is difficult to keep the required capacity in a cabinet, it is advantageous to design the system using a cascade refrigeration system. Use of carbon dioxide and ammonia would be advantageous since ammonia is an environment-friendly working fluid and has a high capacity for performance improvement. To investigate the performance characteristics of the R744-R717 cascade refrigeration system, a theoretical model was developed and performance was analyzed according to cascade heat exchanger operating temperature. The optimal cascade R744 condensing temperature was $-5^{\circ}C$, and maximum COP was 1.13 when the temperature difference of the cascade heat exchanger was $5^{\circ}C$. In addition, the total system COP increased by 1.17 when the cascade temperature gap was $3^{\circ}C$ at the middle temperature of $-7.5^{\circ}C$.

• KIEAE Journal
• /
• v.13 no.3
• /
• pp.61-69
• /
• 2013

The experiment on thermal characteristics of on-dol systems were carried out to apply to New Han-ok's heating system. Change of surface temperature varied with heating times, distribution of surface temperature, radiation property were surveid on four on-dol system in laboratory conditions. Followings are results. 1) "Hwang-to unit" was most favorable condition of the distribution of floor surface temperature. And the results from reaching time to thermal comfort temperature of on-dol system showed that "Hwang-to unit" was the most favorable to continuance of floor temperature. 2) There were a little difference in surface floor radiations of $30^{\circ}C$ for three wet on dol-systems. 3) It was suggested that "Hwang-to unit" is the most appropriate to floor heating system of new han-ok considering eco-friendship and continuance of floor temperature in intermittent heating condition.

• Journal of Mechanical Science and Technology
• /
• v.19 no.12
• /
• pp.2303-2311
• /
• 2005

Super low temperature has many applications nowadays, from the chemical processing, automotives manufacturing, plastic recycling, etc. Considering of its wide application in the present and the future, study of the super-low temperature refrigeration system should be actively carried out. Super low state temperature can be achieved by using multi-stage refrigeration system. This paper present the development and testing of cascade refrigerator system for achieving super-low temperature. On this experiment, two different types of HCFCs refrigerants are utilized, R-22 and R-23 were applied for the high stage and the low-pressure stage respectively. The lowest temperature in the low-pressure evaporator that can be achieved by this cascade refrigeration system is down to $-85^{\circ}C$. This experiment is aimed to study the effect of inlet pressure of the low-pressure stage evaporator and low-pressure stage compressors inlet pressure characteristics to the overall temperature characteristics of cascade refrigeration system.