• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.1125-1130
• /
• 2006

An air source heat pump system producing the ice and water storage energy for cooling and heating of building has been proposed. Cycle design and simulation considering energy balance between heating and cooling capacity has been carried out. The roles of the capacity controlled compressor, refrigerant heating device and air preheating are investigated in detail. System control logic for meeting the predetermined heating capacity when the system is operated at cold climate condition is suggested. Some anticipated problems of the proposed system are also described.

• Design & Manufacturing
• /
• v.17 no.3
• /
• pp.41-47
• /
• 2023

This paper presents the development of a controller that can control the temperature of an heating system based on a thermoelectric module. Temperature controller using Peltier has various external factors such as external temperature, characteristics of an aluminum plate, installation location of temperature sensors, and combination method between the aluminum plate and heating element. Therefore, it is difficult to apply the simulation and simulation results of heating system using Peltier at control algorithm. In general, almost temperature controller is using PID algorithm that finds control gain value heuristically. In this paper, it is proposed mathematical model that explain correlate between the temperature of the heating system and input voltage. And then, optimal parameter of estimated thermal model of the aluminum plate are searched by using genetic algorithm. In addition, based on this estimated model, the optimal PID control gain are inferred using a genetic algorithm. All of the sequence are simulated and verified with proposed real system.

• KIEAE Journal
• /
• v.14 no.2
• /
• pp.11-19
• /
• 2014

Building energy consumption takes up almost 25% of the total energy consumption. Therefore, diversified ways, such as improving wall and window insulation, have been considered to reduce building energy consumption. Recently, green roof system has been explored as an effective alternative for dealing with reducing heating and cooling energy, thermal island effect and improving water quality. However, recent studies regarding a green roof system have only focused on building energy reduction without considering the applied usage, location, and story of the green roof system. Therefore, this study pays attention to the heating and cooling energy in relation to the applied usage, location, and story of a green roof system for investigating its impact on energy reduction. The result of simulations show that the reduction in heating energy consumption is higher when applied to Cherwon-gun province which has a continental climate condition, compared to the city of Busan that is distinguished by its warm climate. Cooling energy saving turns out to be higher when the green roof system is applied to Busan in comparison with Cherwon. As for the applied usage or function of the building, residential space acquires the highest heating and cooling energy saving effect rather than commerce, educational or office space because of HVAC's running time based on usage. When it comes to the story of the green roof, both heating and cooling energy saving become the highest when the green roof is applied to single-storied buildings. The reason is that single story building is affected by the ground largely. Generally, the variations of heating energy consumption are larger than the cooling energy consumption. The outcome of the simulations, when a green roof system is applied, indicates that the energy consumption reduction rate is dynamically responding to the applied usage, location, and story. Therefore, these factors should be counted closely for maximizing the reduction of energy consumption through green roof systems.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.1341-1346
• /
• 2008

This paper presents the heating performance of a water-to-refrigerant type ground source heat pump system (GSHP) installed in a school building. The evaluation of the heating performance has been conducted under the actual operating conditions of GSHP system in the winter. Ten units with the capacity of 10 HP each were installed in the building. Also, a closed vertical typed-ground heat exchanger with 24 boreholes of 175 m in depth was constructed for the GSHP system. For analyzing the heating performance of the GSHP system, we monitored various operating conditions, including the outdoor temperature, the ground temperature, and the water temperature of inlet and outlet of the ground heat exchanger. Simultaneously, the heating capacity and the input power were evaluated for determining the heating performance of the GSHP system. The average heating coefficient of performance (COP) of the heat pump was found to be 5.1 at partial load of 46.9%, while the overall system COP was found to be 4.2.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.788-793
• /
• 2008

This paper presents the heating performance of a water-to-refrigerant type ground source heat pump system (GSHP) installed in a school building. The evaluation of the heating performance has been conducted under the actual operating conditions of GSHP system in the winter. Ten units with the capacity of 10 HP each were installed in the building. Also, a closed vertical typed-ground heat exchanger with 24 boreholes of 175 m in depth was constructed for the GSHP system. For analyzing the heating performance of the GSHP system, we monitored various operating conditions, including the outdoor temperature, the ground temperature, and the water temperature of inlet and outlet of the ground heat exchanger. Simultaneously, the heating capacity and the input power were evaluated for determining the heating performance of the GSHP system. The average heating coefficient of performance (COP) of the heat pump was found to be 5.1 at partial load of 46.9%, while the overall system COP was found to be 4.2.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.11a
• /
• pp.65.2-65.2
• /
• 2010

The aim of this study was to analysis the Heating/cooling performance of Solar Window built in apartments. The solar window is the idea to integrate daylight as a third form of solar energy into a PV/Solar Collector system and allows more control due to the possibility to close the reflectors. However, there can be a conflict between the desire for on one hand daylight and view and on the other hand optimal energy conversion for the PV/Solar Collector system. The process of this study is as follows: 1) The Solar Window system is designed through the investigation of previous paper and work. 2)The simulation program(ESP-r, Therm5.0, Window6.0) was used in Heating/cooling performance analysis. The reference model of simulation was made up to analysis Heating/cooling performance on Solar Window. 3)Selected reference model(Floors:15, Area of Unit:$148.5m^2$) for heating energy analysis, Energy performance simulation with various variants, such as U-value of Solar Window system according to its position and angle. Consequently, When Solar Window system is equipped with balcony window of Apartment, Annual heating and cooling energy of reference model was cut down about 5%~11%.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.403-407
• /
• 2005

Objective of the research is to demonstrate solar thermal space and ground heating system which is integrated to a greenhouse culture facility for reducing heating cost, increasing the value of product by environment control, and developing advanced culture technology by deploying solar thermal system. Field test for the demonstration was carried out in horticulture complex in Jeju Island. Medium scale solar hot water system was installed in a ground heating culture facility. Reliability and economic aspect of the system which was operated complementary with thermal storage and solar hot water generation were analyzed by investigating collector efficiency, operation performance, and control features. Short term day test on element performance and Long term test of the whole system were carried out. Optimum operating condition and its characteristics were closely investigated by changing the control condition based on the temperature difference which is the most important operating parameter. For establishing more reliable and optimal design data regarding system scale and operation condition, continuous operation and monitoring on the system need to be further carried out. However, it is expected that, in high-insolation areas where large-scale ground storage is adaptable, solar system demonstrated in the research could be economically competitive and promisingly disseminate over various application areas.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2002.10a
• /
• pp.318-322
• /
• 2002

In this paper the automatic plate forming system developed by the present research group is introduced, which would be helpful for other researchers. The present system consists of three parts : heating line information generation software, automatic heating apparatus and numerical control system. The numerical control system developed by the present authors is detailed. Performance test for the developed system has been carried out and good results has been obtained. As an extension of the present study, the present automatic plate fanning system will be applied to surfaces found in ship and offshore structure.

• Journal of Power System Engineering
• /
• v.8 no.1
• /
• pp.30-35
• /
• 2004

This paper represents the numerical analysis on effect of the environmental velocity for circular heating source with heat generation. In general heating system, the oil and sheath heater is widely used, but these systems have many problems. So, the heating source with carbon ingredient has been researched in many country about manufacture, thermal and electrical properties. In this research, a circular heating source was studied through numerical analysis on several conditions of unsteady state, beat generation and environmental velocity. The temperature distributions at steady state is appeared as a non-linear pattern with variations of environmental velocity. So, the correlation equation between temperature at steady state and environmental velocity was obtained.

• Journal of Welding and Joining
• /
• v.32 no.1
• /
• pp.47-52
• /
• 2014

Due to of high intensity, lower noise and easy controllability of the heat, induction heating system became well known. Induction heating method has been suggested as substitute for the gas heat source and adopted in the automation of curved hull forming system. In this study, an investigation was accomplished to find the effects on the change of material properties when the induction heating was applied on the mild steel plate. Plates were heated using weaving method to get sufficiently heat affected zone and then cooled with water or in the air. The mechanical properties of the heated plate were evaluated. As results, the tensile test, impact test and microstructures satisfied the class rule.