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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korea Society of Geothermal Energy Engineers
Journal Basic Information
Journal DOI :
Korea Society of Geothermal Energy Engineers
Editor in Chief :
Volume & Issues
Volume 8, Issue 4 - Dec 2012
Volume 8, Issue 3 - Sep 2012
Volume 8, Issue 2 - Jun 2012
Volume 8, Issue 1 - Mar 2012
Selecting the target year
An Experimental Comparison of the Fluidity of G-class cement with Portland cement
Jeon, Jong-Ug ; Won, Jong-Muk ; Choi, Hang-Seok ;
Transactions of the Korea Society of Geothermal Energy Engineers, volume 8, issue 2, 2012, Pages 1~8
The G-class cement is usually used for geothermal well grouting to protect a steel casing which is equipped in a geothermal well to transfer geothermal water from deep subsurface to ground surface. In geothermal grouting process, obtaining appropriate fluidity is extremely important in order to fill cement grout flawlessly. In this paper, a series of the V-funnel and Slump Flow test was performed on both of the Portland cement and the G-class cement in order to compare fluidity and filling ability of those kind of cements. In the result of V-funnel test, the fluidity of G-class cement was evaluated much better than the Portland cement at the water/cement ratio of 0.8. In the case of Slump Flow test, the fluidity of G- class cement was estimated slightly better than the Portland cement at both the water/cement ratio of 0.55 and 0.8. Even though the initial fluidity and filling ability of G-class cement were relatively higher than the Portland cement, the results could be considerably changed with time. The results show that the fluidity and filling ability for geothermal well cementation can be properly controlled with water content and additives for adverse geothermal well environment.
A Study on Heating Characteristics of Ground Source Heat Pump with Variation of Heat Exchange Methods
Cha, Dong-An ; Kwon, Oh-Kyung ; Park, Cha-Sik ;
Transactions of the Korea Society of Geothermal Energy Engineers, volume 8, issue 2, 2012, Pages 9~15
The objective of this study is to investigate the influence on the heating performance for a water-to-water 10RT ground source heat pump by using the water switching and refrigerant switching method. The test of water-to-water ground source heat pump was measured by varying the compressor speed, load side inlet temperature, and ground heat source side temperature. The heating capacity and COP of the heat pump increased with increasing ground heat source temperature. As a result, compared to a refrigerant switching method, the water switching method with counter flow improves the heating capacity and COP by approximately 5% in average, respectively.
Study on the Recognition Analysis of Zero Energy House and Associated Policy Suggestion
Lee, Chung-Kook ; Lee, Jeong-Cheol ; Kim, Sang-Su ; Suh, Seung-Jik ;
Transactions of the Korea Society of Geothermal Energy Engineers, volume 8, issue 2, 2012, Pages 16~26
The consultation with building energy experts working at domestic government-funded research institutes and enterprises on performance set, element technology, and policy for the realization of low-energy and the survey with construction workers on the relevance of climate change in building construction, government support policy, and methodologies for the construction of low-energy house were carried in the study. In addition the public element preference survey on the low-energy house and awareness research on the low-carbonization of building were carried and presented for the development of affordable low-energy house. There was a big difference in the recognition of building energy performance setting and setting for the construction cost to realize it between experts and ordinary citizens in the study. To fill this gap education and promotion of zero energy house and securing economic feasibility through the commercialization of element technology will be needed. The satisfaction in government's zero energy house policy was normally low. To improve this low satisfaction administrative and technical support are considered to be expanded. Common high cost of construction was the top priority to resolve the problem, and enhancing renewable energy grants, tax relief, and substantial cost support could be as detailed solutions.
Suggestion of the Characteristics of Element Technology and the Standard Model through the Comparison of Domestic Zero-energy Houses
Lee, Chung-Kook ; Lee, Jeong-Cheol ; Kim, Sang-Su ; Suh, Seung-Jik ;
Transactions of the Korea Society of Geothermal Energy Engineers, volume 8, issue 2, 2012, Pages 27~35
Five zero energy house models developed in Korea for the purpose of the energy performance were compared and analyzed in the study. The standard passive house model applying common technology and efficient energy performance elements was proposed. Standard passive house 5 models have been developed commonly aiming at 100% energy saving, applying high-performance and high-efficiency exterior thermal insulation, using 3 low-e coated window system, and targeting average 0.65 ACH to enhance privacy. Energy recovery ventilators and dry and cold radiant heating floor has been partially applied. Eco-design techniques such as the awning device, heat insulating door, using natural light have been used. Solar and geothermal systems as the application of renewable energy technologies have been commonly applied. And fuel cells were applied to a partial model. The standard model based on common technical elements and average performance of each element and obtained from five model analysis has been proposed in the study.
A Study on Development Potential of Shallow Geothermal Energy as Space Heating and Cooling Sources in Mongolia
Hahn, Jeong-Sang ; Yoon, Yun-Sang ; Yoon, Kern-Sin ; Lee, Tae-Yul ; Kim, Hyong-Soo ;
Transactions of the Korea Society of Geothermal Energy Engineers, volume 8, issue 2, 2012, Pages 36~47
Time-series variation of groundwater temperature in Mongolia shows that maximum temperature is occured from end of October to the first of February(winter time) and minimum temperature is observed from end of April to the first of May(summer time). Therefore ground temperature is s a good source for space heating in winter and cooling in summer. Groundwater temperatures monitored from 3 alluvial wells in Ulaabaatar at depth between 20 and 24 m are
with average of
but mean annual ground temperature(MAGT) at the depth of 100 m in Ulaanbaatar was about
. Bore hole length required to extract 1 RT's heat energy from ground in heating time and to reject 1 RT's heat energy to ground in summer time are estimated about 130 m and 98 m respectively. But in case that thermally enhanced backfill and U tube pipe placement along the wall are used, the length can be reduced about 25%. Due to low MAGT of Ulaabaatar such as
, the required length of GHX in summer cooling time is less than the one of winter heating time. Mongolia has enough available property, therefore the most cost effective option for supplying a heating energy in winter will be horizontal GHX which absorbs solar energy during summer time. It can supply 1 RT's ground heat energy by 570 m long horizontally installed GHX.
Theoretical Study on Heat Exchanger Performance of a Fin-tube Evaporator with Frost Growth in a
Myung, Chi-Wook ; Cho, Hong-Hyun ;
Transactions of the Korea Society of Geothermal Energy Engineers, volume 8, issue 2, 2012, Pages 48~54
To analyze the cooling performance of fin-tube evaporator in the refrigerator truck using R744 according to frost growth, the analytical model of evaporator was developed under frost and non-frost conditions. The performance of fin-tube evaporator was investigated with frost thickness and indoor temperature. Besides, the performance of evaporator under frost condition was compared to that under non-frost condition. As a result, area of air passage and system performance were decreased as the frost thickness increased. The cooling capacity was reduced by 10%, 20%, 30% when the frost thickness was 0.7 mm, 1.1 mm, and 1.6 mm respectively. At these conditions, the block ratio was 31%, 48%, and 71%. In addition, the outlet quality of refrigerant was not over 1 when the frost thickness was 1.6 mm in spite of high indoor air temperature.
Review on the induced seismic event for artificial reservoir
Jeon, Jong-Ug ; Myoung, Woo-Ho ; Kim, Young-Deug ;
Transactions of the Korea Society of Geothermal Energy Engineers, volume 8, issue 2, 2012, Pages 55~60
In many cases, geothemal wells will not be opened up a geothermal reservoir under such conditions that an extraction of geothermal energy is economically viable without any further measures. Geothermal wells often have to be stimulated, in order to increase productivity. For the non-volcanic area, such as Korea, the hydraulic stimulation is necessary to complete geothermal power plant. The analysis of induced seismic event showed that the thermal resource might have a much wider extent and a much higher generation potential than previously assumed. In order to record compressional and shear waves emitted during fracture stimulation, three-component geophones are placed in a seismometer. The recorded data from one seismometer is the convolution of the source magnitude, the transmission media, and the sensitivity of the instrument.
Performance Prediction of Geothermal Heat Pump System by Line-Source and Modified DST(TRNVDSTP) Models
Sohn, Byong-Hu ;
Transactions of the Korea Society of Geothermal Energy Engineers, volume 8, issue 2, 2012, Pages 61~69
Geothermal heat pump(GHP) systems have been shown to be an environmentally-friendly, efficient alternative to traditional cooling and heating systems in both residential and commercial applications. Although some experimental work related to performance evaluation of GHP systems with vertical borehole ground heat exchangers for commercial buildings has been done, relatively little has been reported on the performance simulation of these systems. The aim of this study is to evaluate the cooling and heating performance of the GHP system with 30 borehole ground heat exchangers applied to an commercial building(
) in Seoul. For this purpose, a typical design procedure was involved with a combination of design parameters such as building loads, heat pump capacity, circulating pump, borehole diameter, and ground effective thermal properties, etc. The cooling and heating performance prediction of the system was conducted with different prediction methods and then each result is compared.