• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.161-166
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• 2007

Various thermostatic valves have been used widely in Korea for conservation of heating energy and enhancement of thermal comfort in residential buildings. But heating control performances of thermostatic valves extensively vary with the design and operational conditions of the heating system, climate condition and others. An experimental method was carried out in this study to analyze heating control characteristics by temperature sensing methods of thermostatic valves for various parameters, such as supply temperatures and flow rate of hot water, the position of room thermostats and outdoor air temperatures. As a result, the heat flow rate per day of S-Valve($34^{\circ}C$-Type) of water temperature sensing method was liked that of C-Valve of indoor air temperature sensing method with stage 3.3 of room thermostat in case supply temperature of hot water was $45^{\circ}C$, flow rate was 1.3 L/min and outdoor air temperature was $7.8^{\circ}C$.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.11
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• pp.544-547
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• 2006

In this paper, we present a temperature-controlled system for MEMS electrical resistance heaters without a temperature sensor. To rapidly control the heater temperature, the microheater system developed consists of a power supply, power amplifier, digital ${\underline{P}}roportional-{\underline{I}}ntegral-{\underline{D}}ifferential$ (PID) controller, and a quarter bridge circuit with the microheater and three resistors are nominally balanced. The microheaters are calibrated inside a convection oven to obtain the temperature coefficient with a linear or quadratic fit. A voltage amplifier applies the supply voltage proportional to the control signal from the PID controller. Small changes in heater resistance generate a finite voltage across the quarter bridge circuit, which is fed back to the PID controller to compare with the set-point and to generate the control signal. Two MEMS microheaters are used for evaluating the developed control system - a NiCr serpentine microheater for a preconcentrator and a Nickel microheater for ${\underline{P}}olymerase\;{\underline{C}}hain\;{\underline{R}}eaction$ (PCR) chip.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.264-269
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• 2011

A precision of temperature control in the manufacturing process would be an important factor and become the main key to control production quality. Mostly manufacture machinery used oil as a coolant in their system so an accurate oil temperature control system become an absolute need in industrial field. This paper presents a experiment research to control the oil temperature constant at target point, in this experiment is $35^{\circ}C$ by using an inverter attached in compressor to varying the compressor speed. This control has been completed and tested through an experiment with different heat load of 4kW, 6kW, 7kW, 8kW and 10kW given under temperature constant room conditioned as $25^{\circ}C$. The results had shown the temperature deviation in the refrigerator has around $0.2^{\circ}C$ and the COP is 2.5 gained at 8kW and 10kW.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.124-124
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• 2022

Wheat (Triticum aestivum L.) is the major staple foods and is in increasing demand in the world. The elevated temperature due to changes in climate and environmental conditions is a major factor affecting wheat development and grain quality. The optimal temperature range for winter wheat is between 15~25℃, it is necessary to study the physiological characteristic of wheat according to the elevated temperature. This study presents the effect of elevated temperature on the yield and quality of two Korean bread wheat (Baekkang and Jokyoung) in a temperature gradient tunnel (TGT). Two bread wheat cultivars were grown in TGT at four different temperature conditions, i.e. TO control (near ambient temperature), T1 control+1℃, T2 control+2℃, T3 control+3℃. The period from sowing to heading stage has accelerated, while the growth properties including culm length, spike length and number of spike, have not changed by elevated temperature. On the contrary, the number of grains per spike and grain yield was reduced under T3 condition compared with that of control condition. In addition, the. The grain filling rate and grain maturity also accelerated by elevated temperature (T3). The elevating temperature has led to increasing protein and gluten contents, whereas causing reduction of total starch contents. These results are consistent with reduced expression of starch synthesis genes and increased gliadin synthesis or gluten metabolism genes during late grain filling period. Taken together, our results suggest that the elevated temperature (T3) leads to reduction in grain yield regulating number of grains/spike, whereas increasing the gluten content by regulating the expression of starch and gliadin-related genes or gluten metabolism process genes expression. Our results should be provide a useful physiological information for the heat stress response of wheat.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.448-453
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• 2005

Temperature Control Valve (TCV) is one of the useful temperature control devices, which is used to control constant temperature of working fluid in power and chemical plants and domestic water supply systems. TCV is composed of body, cylinder and piston, and the body shape has a symmetrical H-type. In general, it has several inlet and outlet holes, and its shape is like as tubular sleeve. The piston has three rings two rings of the end of piston have the function of controlling inlet flow rate with hot and cold working fluids, the center ring has the function of preventing hot and cold water from intermixing. Consequently, the shapes of piston and cylinder are the main design parameters in the performance of TCV. In this study, numerical analyses were carried out with two different piston and cylinder shapes to investigate the functions as a temperature control valve and the flow characteristics according to piston opening grade in TCV. Using a commercial code, FLUENT, velocity and pressure fields in TCV are obtained under steady, standard $k -{\epsilon}$ turbulence model and no-slip condition.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1359-1361
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• 2003

This paper describes a remote monitoring system of temperature control for cold-storage of farm produce. In cold-storage, it is important that farm produces are stored as fresh. Unfortunately, when an operator goes out from the cold-storage, the temperature could be changed due to the various reasons, for an example, a valve of cooler is broken. The temperature change results in a serious problem of the quality of farm produce. To prevent the problem, the operator has to look to the current state of the temperature of the cold-storage, even he is in long away. Thus, the monitoring system to show the temperature is required to the operator who can move away. Therefore, this paper describes the remote monitoring system of the temperature. The proposed system is expected to help the operator's facilities, and the management of farm produce.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.55 no.3
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• pp.123-127
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• 2006

In a heating control system, the indoor temperature controller transfers temperature signals inputted from the temperature sensor and the user to the valve controller. The valve controller receives these signals then the valve controller controls the valve driving motor on two position control and controls the indoor temperature. When setting up a new valve driving motor from a long distance it is necessary to set up a new valve controller. But occasionary, due to construction, It is impossible to wire between the existing valve controller and the new valve controller. In this situation, the new and existing valve controllers can communicate via power line communication. In this paper it is proposed heating control system controls on two position control via power line communication.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.1150-1155
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• 2006

In a heating control system, the indoor temperature controller transfers temperature signals inputed from the temperature sensor and the user to the valve controller. The valve controller recieves these signals then the valve controller controls the valve driving motor on two position control and controls the indoor temperature. When setting up a new valve driving motor from a long distance it is necessary to set up a new valve controller. But occasionary, due to construction, it is impossible to wire between the existing valve controller and the new valve controller. In this situation, the new and existing valve controllers can communicate via power line communication. In this paper it is proposed heating control system controls on two position control via power line communication.

• Journal of Hydrogen and New Energy
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• v.28 no.4
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• pp.369-376
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• 2017

Temperature and humidity regulations of an open-cathode PEM fuel cell with balance of plant (BOP) are developed in this study. The axial fan, a bubble humidifier, set of solenoid valves and a controller are used to perform temperature and humidity control simultaneously. A fuzzy controller is designed, and it shows its superiority in real-time controlling for strong non-linear dynamical fuel cell system. The axial fan speed is used for temperature control and solenoid valve on/off signal of the bubble humidifier is used for humidity control. The axial fan speed is controlled to keep the fuel cell temperature within the desired point. Meanwhile, the bubble humidifier is utilized to moisture hydrogen to manage the water content of membrane. The results show that the proposed fuzzy controller effectively increases the output power of 10% for a PEM fuel cell.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.7
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• pp.1129-1136
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• 2008

The gaiter is one of the personal protective equipments worn in various industrial sites. This study was performed on humans to investigate the physiological strain of wearing gaiters and to compare control gaiters that are currently on the market and new gaiters that are developed for alleviating heat stress. Experiments were conducted in a climatic chamber of WBGT $30.0\pm0.7^{\circ}C$ under five differed experimental conditions: None, Control A, Control B, New A, New B. The results were as follows. The temperature inside gaiters was significantly lower in both New A and New B than in both Control A and Control B and the difference between news and controls was 1$^{\circ}C$ (p<.01). The humidity inside gaiters in both New A and New B were higher than that in Control A, and lower than that in Control B (p<.01). The outermost surface temperature of the gaiter was the lowest in None and it increased in the following order: New B < New A < Control A < Control B. Mean skin temperature was higher by 0.14$^{\circ}C$ in wearing gaiters than in no gaiters. Skin temperatures in lower body were lower in Control than in New and skin temperature in upper body were higher in Control than in New (p<.01). Local sweat rate, total weight loss and subjective sensations did not show a significant difference according to the gaiters. It was concluded that wearing gaiters affected distribution of skin temperature and local sweat rate.