• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.1
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• pp.117-124
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• 2003

Thermal design fur satellite propulsion system has been performed. Overall design requirements and the constitution for propulsion system is described. To meet the thermal design requirements, both a primary and a redundant heater circuit, each with two thermostats placed in series, will protect each hydrazine-wetted components, even if one heater circuit fails to operate. Heater power is turned off if any one of these thermostats is opened at its higher setpoint. Thus, even if one thermostat is failed closed, the second thermostat will turn off the heater. All such components shall be insulated with MLI. Propulsion heater sizing based on the constant worst cold case condition is conducted through thermal analysis. All heaters selected fur propulsion components operate to prevent propellant freezing satisfying the thermal requirements for the propulsion subsystem over the worst case average voltage, i.e. 25 volts.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.77-82
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• 2001

Thermal design for KOMPSAT-2 propulsion system has been performed. Overall design requirements and the constitution for propulsion system is described. To meet the thermal design requirements, both a primary and a redundant heater circuit, each with two thermostats placed in series, will protect each hydrazine-wetted components, even if one heater circuit fails to operate. Heater power is turned off if any one of these thermostats is opened at its higher setpoint. Thus, even if one thermostat is failed closed, the second thermostat will turn off the heater. All such components shall be insulated with MLI. Propulsion heater sizing based on the constant worst cold case condition is conducted through thermal analysis. All heaters selected for propulsion components operate to prevent propellant freezing satisfying the thermal requirements for the propulsion subsystem over the worst case average voltage, i.e. 25 volts.

• Journal of Korean Institute of Fire Investigation
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• v.11 no.1
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• pp.63-73
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• 2007

In this paper, we discussed the hazard of ignition on the bimetal type thermostat molded by phenol resin with case study and accelerated aging test. We experimented three type thermostats molded by phenol resin which are used on hot/cold water dispenser. On the case study, the thermostat was origin of 6re and dry tracking occurred around it's moveable contactor. On the accelerated aging test, the more thermostat was switched, the more damaged it become. One of the A-type thermostats that is similar type on the case study fired around moveable contactor. We therefore confirmed that the tracking around the moveable contactor of bimetal type thermostat molded by phenol resin could be origin of fire and it is available to reduce of fire that using noncombustible material for molding of bimetal type thermostat.

• Journal of the Korea Safety Management & Science
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• v.26 no.1
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• pp.31-38
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• 2024

In this paper, as there are many cases of fires occurring due to the failure or inoperability of the thermostat of electronic products, the purpose is to test and analyze the risks and probabilities through fire cases and reproduction experiments, and suggest countermeasures. Among electronic products, water purifiers are composed of a refrigerant system with a compressor to make cold water, a heating device to make hot water, and an electric device used as an energy source. Due to the nature of the water purifier manufacturing, these devices are subject to a lot of moisture and dust. etc. exist in large quantities and use electrical energy, so there is a possibility of fire due to short circuit in the wire, electrical abnormal overheating (tracking phenomenon) in the thermostat, electronic board, starting relay, etc., and overheating of the heating device (Band Heater). there is. Therefore, in order to prevent fires from these devices, a system to remove foreign substances inside the water purifier is necessary, the use of heat-resistant (fire-resistant) wires for electrical devices is essential, and the use of non-combustible materials (semi-combustible materials) for each part is necessary to prevent fire. The risk must be eliminated through prevention and combustion expansion prevention devices.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.221-226
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• 2020

Smart homes have become the state of the art in the reduction and monitoring of energy usage within a residential setting. Emerging threats such as climate change, global warming and volatility in energy prices have fuelled the interest in smart systems. Given that environmental sustainability has become a more significant factor for consumers, this research examines whether consumers' attitudes toward smart home services for efficient energy management differ according to their regulatory focus. Specifically, it is predicted that consumers will have more favorable attitudes toward smart home services for efficient energy management when they are promotion-focused (vs. prevention-focused). The results indicate that respondents with a promotion (vs. prevention) focus reported significantly more favorable attitudes toward smart home services for energy management (e.g., smart cooling/heating system, smart ventilation & air conditioning system, smart thermostats, smart plugs, and smart switches). We suggest that regulatory focus may be an effective marketing and segmentation tool in promoting smart home services for energy management and facilitating their receptiveness to the services.

• Journal of Sensor Science and Technology
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• v.3 no.3
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• pp.3-8
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• 1994

Flow sensor was fabricated with PTC thermistor usually operating as thermostats. The PTC thermistor was manufactured with $(Ba_{0.7}Sr_{0.3})TiO_{3}$ powder and its resistivity as a function of flow velocity was investigated. The resistivity changed from 4.45 $k{\Omega}{\cdot}cm$ to 3.95 $k{\Omega}{\cdot}cm$ as flow velocity varied 0 cm/s to 5 cm/s The sensitivities of the PTC thermistor were -204 (${\Omega}{\cdot}cm$)/(cm/s) and -24 (${\Omega}{\cdot}cm$)/(cm/s) at the flow velocity of 1 cm/s and 5 cm/s, respectively.

• Solar Energy
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• v.11 no.2
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• pp.29-33
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• 1991

The present paper deals with two types of heating methods widely used for the Radiant Floor heating systems in Korea. Of these, one method circulates hot water according to the predefined schedule ("intermittent heating") while the other runs the system with the aid of thermostats ("continuous heating"). The standard version of SERI-RES has been modified for the numerical simulation of the problem. Preliminary results show relatively large temperature swings in the case of intermittent heating with solar availability. On the other hand, the case of continuous heating would avoid such undesirable temperature fluctuations. These results are also verified by experimental evaluations.

• 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 $7.8^{\circ}C$.

• Journal of KIISE
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• v.44 no.4
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• pp.417-422
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• 2017

Anomaly detection is the identification of data that do not conform to a normal pattern or behavior model in a dataset. It can be utilized for detecting errors among data generated by devices or user behavior change in a social network data set. In this study, we proposed a new approach using rank correlation coefficient to efficiently detect abnormal data in devices of a building. With the increased push for energy conservation, many energy efficiency solutions have been proposed over the years. HVAC (Heating, Ventilating and Air Conditioning) system monitors and manages thousands of sensors such as thermostats, air conditioners, and lighting in large buildings. Currently, operators use the building's HVAC system for controlling efficient energy consumption. By using the proposed approach, it is possible to observe changes of ranking relationship between the devices in HVAC system and identify abnormal behavior in social network.