단독주택 건물 그린리모델링에 따른 건물 에너지 성능과 운전비용 절감 효과 평가

손병후,손병후,이수인,강재식 한국 지열 · 수열에너지학회 2023 한국지열에너지학회논문집 Vol.19 No.4

The Government the Republic of Korea is showing a lot of interest in net zero-energy buildings (NZEBs) to reduce energy consumption of buildings and to promote green growth policy in construction sector. The application of building passive technologies and renewable energies is essential to achieving NZEBs. Green remodeling reinforced the insulation of the exterior walls and roofs of the buildings and replaced high-efficiency windows and doors. In this study, the energy performance before and after green remodeling applied in a detached house was comparatively analyzed for baseline scenario and three different ones, ALT 1, ALT 2 and ALT 3. A building modeling and simulation software (DesignBuilder V7.0) with EnergyPlus (V9.4) calculation engine was used to calculate the energy demand and energy consumption for each scenario. Based on the calculation results of the building's energy demand for baseline, it was determined that the target building required more heating energy than cooling energy. The simulation results also showed that the implementation of building envelope performance improvement technologies (ALT 1) could notably decrease the heating energy consumption of the building. After the remodeling (ALT 1), the source energy consumption per unit floor area was assessed to be reduced by 65.2%, compared to prior remodeling of 338.7 kWh/m2 -y. Meanwhile, ALT 2 can achieve energy savings of 67.7% and ALT 3 can achieve savings of 73.1%. Following completion of the remodeling project, actual construction costs, and on-site measurements and verification results will be gathered and compared with the simulation results. Additionally, economic analysis including construction costs and payback period will be conducted using actual site data.

시뮬레이션을 통한 노인 요양 시설의 지열 히트펌프 시스템 적용 가능성 평가

손병후,손병후,김영선,이승언 한국 지열 · 수열에너지학회 2023 한국지열에너지학회논문집 Vol.19 No.4

This study analyzes the energy performance of a elderly care center building and the applicability of a ground source heat pump (GSHP) system through simulation approach. For this purpose, a building information modeling (BIM) program and an energy performance calculation program were used. The impact of the mechanical ventilation system on the energy requirements of the heating and cooling system and the indoor environment was also analyzed, focusing on the change in indoor carbon dioxide (CO2) concentration, which is a representative indicator of the indoor environment (air quality). The simulation results showed that the target building exceeds Level 7 in terms of simulated primary energy consumption or actual energy consumption. In addition, it was analyzed that the target building could not maintain the indoor CO2 concentration below the standard concentration by natural ventilation through window opening alone. Combining the GSHP system with the mechanical ventilation system (Case B and Case C) can further reduce the overall energy consumption by reducing the amount of outdoor air introduced by opening windows. The cost savings compared to the baseline case are estimated to be 67.3% for Case A, 63.7% for Case B, 65.5% for Case C, and 42.5% for Case D. It is necessary to analyze the impact of various renewable energy technologies and passive ones on the energy performance and indoor environment of elderly care centers.

군사시설 내 지열 히트펌프 시스템 적용에 따른 에너지 성능과 비용 절감 효과 평가

손병후,조경주,조동우,손병후 한국 지열 · 수열에너지학회 2022 한국지열에너지학회논문집 Vol.18 No.4

The Ministry of National Defense of the Republic of Korea is showing a lot of interest in net zero-energy buildings (NZEBs) to reduce energy consumption of military facilities and to promote green growth policy in military sector. The application of building passive technologies and renewable energies is essential to achieving NZEBs. This paper analyzed energy performance and energy cost on the conventional heating and cooling system (baseline scenario) and three different alternative scenarios (ALT 1, ALT 2 and ALT 3) applied in a hypothetical military building. A building modeling and simulation software (DesignBuilder V6.1) with EnergyPlus calculation engine was used to calculate the energy consumption for each scenario. Overall, when the GSHPs are applied to both space airconditioning and domestic hot water (DHW) production, Alt-2 and Alt-3, the amount of energy consumption for target building can be greatly reduced. In addition, when the building envelope performance is increased like Alt-3, the energy consumption can be further reduced. The annual energy cost analysis showed that the baseline was approximately 161 million KRW, while Alt-3 was approximately 33 million KRW. Therefore, it was analyzed that the initial construction cost increase could be recovered within about 6.7 years for ALT 3. The results of this study can help decision-makers to determine the optimal strategy for implementing GSHP systems in military buildings through energy performance and initial construction cost assessment.

휜이 있는 협소 사각 유로에서 대향류 기/액 2상유동 ( Counter-Current Gas-Liquid Two-Phase Flow in Narrow Rectangular Channels with Offset Stripe Fins )

손병후,김병주,정시영 대한기계학회 2001 대한기계학회 춘추학술대회 Vol.1 No.5

열응답 시험과 변수 평가 모델을 이용한 그라우트/토양 혼합층의 열전도도 산정

손병후,신현준,안형준 대한설비공학회 2005 설비공학 논문집 Vol.17 No.2

The performance of U-tube ground heat exchanger for geothermal heat pump systems depends on the thermal properties of the soil, as well as grout or backfill materials in the borehole. In-situ tests provide a means of estimating some of these properties. In this study, in-situ thermal response tests were completed on two vertical boreholes, 130 m deep with 62 mm diameter high density polyethylene U-tubes. The tests were conducted by adding a monitored amount of heat to water over a 17∼18 hour period for each vertical boreholes. By monitoring the water temperatures entering and exiting the loop and heat load, overall thermal conductivity values of grout/soil formation were determined. Two parameter estimation models for evaluation of thermal response test data were compared when applied on the same temperature response data. One model is based on line-source theory and the other is a numerical one-dimensional finite difference model. The average thermal conductivity deviation between measured data and these models is of the magnitude 1% to 5%.

벤토나이트 그라우트의 열물성 측정 및 열물성이 수직 지중열교환기 설계 길이에 미치는 영향

손병후 한국 지열 · 수열에너지학회 2019 한국지열에너지학회논문집 Vol.15 No.2

In a ground-source heat pump (GSHP) system, a vertical ground heat exchanger (GHE) is widely accepted due to a higher thermal performance. In the vertical GHE, grout (also called grouting material) plays an important role in the heat transfer performance and the initial installation cost of the GHE. Bentonite-based grout has been used in practice because of its high swelling potential and low hydraulic conductivity. This study evaluated the thermo-physical properties of the bentonite-based grouts through lab-scale measurements. In addition, we conducted performance simulation to analyze the effect of mixed ratio of grouts on the design length and thermal performance of the vertical GHE. The simulation results show that thermally-enhanced grouts improve the heat transfer performance of the vertical GHE and thus reduce the design length of GHE pipe.

지열원 열펌프 시스템의 냉난방 성능 평가

손병후,조정식,신현준,안형준 대한설비공학회 2005 설비공학 논문집 Vol.17 No.1

The main objective of the present study is to investigate the performance characteristics of a ground-source heat pump(GSHP) system with a 130 m vertical and 62 mm nominal diameter U-tube ground heat exchanger. In order to evaluate the performance analysis, the ground-source heat pump connected to a test room with 90 m2 floor area in the Korea Institute of Construction Technology(37o39'N, 126o48'E) was designed and constructed. This ground-source heat pump system mainly consisted of ground heat exchanger, indoor heat pumps and measuring devices. The cooling and heating loads of the test room were 5.5 and 7.2 kW at design conditions, respectively. The experimental results were obtained from July 2, 2003 to July 1, 2004. The cooling and heating performance coefficients of the system were determined from the measured data. The average cooling and heating COPs for the system were obtained to be 4.90 and 3.96, respectively. The temperature variations in ground and the ground heat exchanger pipe surface at different depths were also measured.

협소 사각 유로에서 대향류 기/액 2상 유동양식 ( Counter-Current Gas-Liquid Two-Phase Flow regimes in Narrow Rectangular Channels )

손병후,김병주,정시영 대한기계학회 2000 대한기계학회 춘추학술대회 Vol.- No.-

단독주택용 지열 냉난방 시스템의 개발 필요성

손병후 대한설비공학회 2009 설비저널 Vol.38 No.1

지중 열교환기 보어홀 그라우팅 재료의 열전도도 측정

손병후,신현준 대한설비공학회 2006 설비공학 논문집 Vol.18 No.6

This paper concerns the measurement of thermal conductivity of grouting materials for ground loop heat exchanger. A thermal conductivity meter, QTM-500 based on modified transient hot wire method was used to measure the thermal conductivity of neat bentonite and mixtures of bentonite and various additives. Relative to the total mixture mass, as the percent additive was increased the mixture thermal conductivity increased. For the bentonite-silica sand mixtures, the higher density of the sand particles resulted in much higher mixture thermal conductivity. The quartzite and silica sands produced the largest increases in mixture thermal conductivity, while common masonry and limestone sands produced lower thermal conductivity increases.