• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.4 no.2
• /
• pp.1-7
• /
• 2008

GSHP(Ground Source Heat Pump) has been extensively disseminated due to the recent increasing demand over new and renewable energy. However, the system reliability has been key issues and barriers to insure a better system performance as designed originally in ISO (international standard organization) standard. This paper introduces a systematic method to verify its intended design target so called as ISO performance data based commissioning technology for a water to air GSHP system. The commissioning technology starts from are to the international standard ISO performance data of a GSHP model and to compare its installed operation data and to calibrate and tune to the target optimum operation parameters. Results indicated that cooling capacity could be raised up to 76.6% from 46.6% from this proposed commissioning technology.

• Journal of Power System Engineering
• /
• v.19 no.1
• /
• pp.24-30
• /
• 2015

Geothermal energy is used in various types, such as power generation, direct use, and geothermal heat pumps. Geothermal energy with high temperature have been used for power generation for more than a century. The purpose of the study is to investigate flow and electricity power characteristics of hydraulic turbine for power generation of geothermal heat pump type with closed-system. The differences between the four types of hydraulic turbine, are different from the blade shape, volume, angle and etc. In case of prototype(1), pressure at blade was reduced to 2.1 bar, the kinetic energy of blade increased by increasing flow velocity(4.1 m/s). The increase of flow velocity at the blade edge markedly appeared, to increase the kinetic energy of the rotating shaft. In case that gateway in hydraulic turbine was installed, operating torque and RPM(1,080) of the rotating shaft increased respectively. Although rotational speed of prototype(2) compared to prototype(1) was reduced, the power generation capacity was greater about 3.4 times to 97 W. The most power of 255W was generated from prototype (4).

• 한국태양에너지학회:학술대회논문집
• /
• 2011.11a
• /
• pp.328-332
• /
• 2011

The conclusion is derived from the arranged results and using a simulation by determining the shape of an optimum heat pump which is appropriate for small scale houses. It is concluded as 3 meters long for the laying depth of underground piping of the horizontal type geothermal heat pump system in regard to the 5 RT capacity standard that is suitable for a small scale house. The shape of the horizontal type geothermal heat pump system for a small scale house is theThree pipe shape whose trench length is short and pipe length laid in a trench is short. It is 9 for the number of laying pipes that is most appropriate to system.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.9 no.2
• /
• pp.8-15
• /
• 2013

Recently, an interest in the use of renewable energy has been growing up due to the rise of raw material price, international oil price and depletion of fossil energy. Ground source heat pump system has a high efficiency by using the constant temperature of underground and various types of the systems have been installed and utilized in the building. there are few studies on the system performance factors in the SCW system. Furthermore, even though the performance of the system depends on the temperature of heat source, the research on their relationship is rare. In this research, in order to analyze the performance factor for the open-loop system the monitoring of the real building with the standing column well systems and the simulation with building model were conducted.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.6 no.1
• /
• pp.1-7
• /
• 2010

In this paper, an experimental study on the cooling operation characteristics for different entering water temperatures in geothermal heat pump system are carried out by using Lab VIEW system program Set-point temperature controls for cooling water and supply air temperatures is applied to analyze the energy consumption and control performances. As a result, the system responses show that different entering water temperatures(EWT) effect greatly on the energy consumption and system COP.

• Journal of the Korean Solar Energy Society
• /
• v.33 no.1
• /
• pp.79-88
• /
• 2013

This study set out to evaluate the economy, environmentality, and complexity (economy+environmentality) of fire station buildings of public service facilities and propose ways to apply the optimization of renewable energy system to fire station buildings. As for economy according to life cycle costs, economy increased when the application percentage of the geothermal and solar heat system increased over the three renewable energy system types (geothermal, solar heat, and solar photovoltaic). On the other hand, economy decreased when the application percentage of the solar photovoltaic system increased. As for environmentality according to tons of carbon dioxide, environmentality decreased when the application percentage of the geothermal and solar heat system increased. Environmentality increased when the application percentage of the solar photovoltaic system increased. As for complexity (economy+environmentality) according to the weighted coefficient method, complexity increased when the application percentage of the geothermal system increased. It was highest at the combination of the solar heat system (20%) and geothermal system (80%). On the other hand, complexity decreased when the application percentage of the solar photovoltaic system increased. It was lowest at the combination of the solar photovoltaic system (80%) and geothermal system (20%).

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.3 no.2
• /
• pp.9-15
• /
• 2007

Thermal conductivity of rocks is one of the most important parameters in designing a geothermal heat pump system, because heat exchange rate depends primarily on thermal conductivity of rocks. In this paper, the measurement methods of thermal conductivity, thermal conductivity of rocks, and heat exchange rate are discussed.

• Journal of the Korean Solar Energy Society
• /
• v.35 no.1
• /
• pp.45-52
• /
• 2015

The government is fostering a renewable energy industry as an alternative to handle the energy crisis. Among the renewable energy systems available, geothermal energy is being highlighted as being highly efficient and safely operable without the effect of outdoor air. Accordingly, a study on the geothermal heat pump is in progress in various worldwide perspective. However, Geothermal energy is only in charge of part load of the building due to the high initial installation cost in korea. Moreover, its efficiency is reduced due to the use of independent existing heat sources. In this study, after selecting the building containing the actual installed geothermal heat pump, the use of excellent geothermal heat pump systems was maximized in terms of the energy efficiency. The objective of this study is to show the operation method of geothermal heat pump system to improve energy efficiency through the TRNSYS simulation. This paper proposed operation methods of geothermal heat pump control according to outdoor air temperature. The result of this study is that existing operation method had some problems and if offered improvement is applied to real condition, energy consumption would be decreased.

• Journal of the Korean Solar Energy Society
• /
• v.32 no.6
• /
• pp.60-67
• /
• 2012

Government Geothermal Cooling-Heating Projects has made efforts to reduce GHG(Greenhouse Gas) emissions and to manage cost of greenhouse farm households. This study evaluated the economic benefits of heating load rate of change by comparing Geothermal Cooling-Heating System with the existing system(greenhouse diesel heating) in the Government Geothermal Cooling-Heating Projects. Economic analysis results shows that, 1) When installing the Cooling-Heating system according to the ratio of 70% heating load in policy standards, the geothermal cooling-heating system has economic efficiency with greenhouse type or scale independent because the investment cost is recovered within 7 years. And It was more economic efficiency the ratio of 50% heating load than70% heating load. 2) When installing the Cooling-Heating system according to the glass greenhouse of the ratio of 90% heating load, pay period of investment cost is recovered within 5 years. Therefore it is necessary to apply flexible heating sharing according to greenhouse type or scale.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.10a
• /
• pp.365-368
• /
• 2008

This experiment is significant because we can provide information by measuring effect of energy saving for whom plan to install a geothermal heat & cooling system. The result shows geothemal system can save about 50% of energy(heating : 35%, cooling : 60%) and we verified that when using curtain can help saving $4{\sim}12%$ of energy additionally