단독주택용 지열 열펌프 시스템의 경제성과 이산화탄소 배출 저감 가능성 평가

손병후(Byonghu Sohn),강신형(Shin-Hyung Kang) 대한설비공학회 2009 대한설비공학회 학술발표대회논문집 Vol.2009 No.-

Because of their low operating and maintaining costs, ground-source heat pump(GSHP) systems are an increasingly popular choice for providing heating, cooling and water heating to public and commercial buildings. Despite these advantages and the growing awareness, GSHP systems to residential sectors have not been adopted in Korea until recently. A feasibility study of a residential GSHP system was therefore conducted using the traditional life cycle cost(LCC) analysis within the current electricity price framework and potential scenarios of that framework. As a result, when the current residential electricity costs for running the GSHP system are applied, the GSHP system has weak competitiveness to conventional HVAC systems considered. However, when the operating costs are calculated in the modified price frameworks of electricity, the residential GSHP system has the lower LCC than the existing cooling and heating equipments. The calculation results also show that the residential GSHP system has lower annual prime energy consumption and total greenhouse gas emissions than the alternative HVAC systems considered in this work.

하이브리드 지중열교환기 이용 히트펌프 시스템의 난방 운전 특성

손병후(Byonghu Sohn) 대한설비공학회 2021 대한설비공학회 학술발표대회논문집 Vol.2021 No.6

This paper presents the heating performance analysis results of a heat pump system using a hybrid ground heat exchanger(HGHE). In this paper, the HGHE refers to the ground-coupled heat exchanger using both a surface water heat exchanger (SWHE) and a vertical ground heat exchanger(VGHE). In order to evaluate the systems performance, we installed a monitoring system to measure the temperature and power consumption of a heat pump and then collected operation data with 4 different load burdened ratios of the HGHE. During the whole measurement period, the average heating capacity of a water-to-water heat pump unit was 37.3 kW. In addition, the compressor of the heat pump consumed 9.4 kW of power, while the circulating pump of the HGHE used 6.7 kW of power. Therefore the average heating coefficient of performance(COP) for the heat pump unit was 4.0, while the entire system including the circulating pump was 2.7. Finally, the parallel use of SWHE and VGHE was beneficial to the system performance; however, further researches are needed to optimize the design data for various load ratios of the HGHE.

하이브리드 지중열교환기 적용 지열 히트펌프 시스템의 난방 성능 분석

손병후(Byonghu Sohn) 한국지열·수열에너지학회 2020 한국지열에너지학회논문집 Vol.16 No.3

This paper presents the heating performance analysis results of a ground-source heat pump (GSHP) system using hybrid ground heat exchanger (HGHE). In this paper, the HGHE refers to the ground heat exchanger (GHE) using both a surface water heat exchanger (SWHE) and a vertical GHE. In order to evaluate the system performance, we installed monitoring sensors for measuring temperatures and power consumption, and then measured operation data with 4 different load burdened ratios of the HGHE. During the entire measurement period, the average heating capacity of the heat pump was 37.3 ㎾. In addition, the compressor of the heat pump consumed 9.4 ㎾ of power, while the circulating pump of the HGHE used 6.7 ㎾ of power. Therefore, the average heating coefficient of performance (COP) for the heat pump unit was 4.0, while the system including the circulating pump was 2.7. Finally, the parallel use of SWHE and VGHE was beneficial to the system performance; however, further researches are needed to optimize the design data for various load ratios of the HGHE.

토양 열전도도와 수분함량이 수평형 지중열교환기 설계 길이에 미치는 영향

손병후(Byonghu Sohn) 한국지열·수열에너지학회 2012 한국지열에너지학회논문집 Vol.8 No.1

This paper reviewed and evaluated some of the commonly used prediction models for thermal conductivity of soils with the experimental data. Semi-theoretical models for two-component materials were found inappropriate to estimate the thermal conductivity of dry state soils. It came out that the model developed by Cote and Konrad gave the best overall prediction results for unsaturated soils available in the literature. However, it still needs to be improved to cover a wider range of soil types and degrees of saturation. In the present study, parametric analysis is also conducted to investigate the effect of soil type and moisture content on the horizontal ground heat exchanger design. The analysis shows that horizontal ground heat exchanger pipe length is reduced with the increase of soil thermal conductivity and water content. The calculation results also show that horizontal ground heat exchanger size can be reduced to a certain extent by using backfilling material with a higher thermal conductivity of solid particles.

단독주택 적용 지열 히트펌프 시스템의 성능 분석

손병후(Byonghu Sohn),최종민(Jong Min Choi),최항석(Hangseok Choi) 대한설비공학회 2011 설비공학 논문집 Vol.23 No.6

Ground-coupled heat pump(GCHP) 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 work related to performance evaluation of GCHP systems for commercial buildings has been done, relatively little has been reported on the residential applications. The aim of this study is to evaluate the cooling and heating performances of a vertical GCHP system applied to an artificial detached house(117 ㎡) in Seoul. For this purpose, a typical design procedure was involved with a combination of design parameters such as building loads, heat pump capacity, borehole diameter, and ground thermal properties, etc. The cooling and heating performance simulation of the system was conducted with different prediction times of 8760 hours and 240 months. The performance characteristics including seasonal system COP, average annual power consumption, and temperature variations related to ground heat exchanger were calculated and compared.

병원 건물에 설치된 냉각탑 병용 지열 히트펌프 시스템의 냉방 성능

손병후(Byonghu Sohn),이두영(Doo-Young Lee),민경천(Kyung-Chon Min) 한국지열·수열에너지학회 2016 한국지열에너지학회논문집 Vol.12 No.1

This paper presents the measurement and analysis results for the cooling performance of ground-coupled heat pump (GCHP) system using a cooling tower as a supplemental heat rejector. In order to demonstrate the performance of the hybrid approach, we installed the monitoring equipments including sensors for measuring temperature and power consumption, and measured operation parameters from May 1 to October 30, 2014. The results showed that the entering source temperature of brine returning from the ground heat exchanger was in a range of design target temperature. Leaving load temperatures to building showed an average value of 11.4°C for cooling season. From the analysis, the daily performance factor (PF) of geothermal heat pumps ranged from 4.4 to 5.2, while the daily PF of hybrid GCHP system varied from 3.0 to 4.0 over the entire cooling season.

이중탐침법을 이용한 수평형 지중열교환기 뒤채움재의 열확산계수 측정

손병후(Byonghu Sohn),최항석(Hangseok Choi) 한국지열·수열에너지학회 2011 한국지열에너지학회논문집 Vol.7 No.2

Storage and transfer heat in soils are governed by the soil thermal properties and these properties are therefore needed in many engineering applications, including horizontal ground heat exchanger for ground-coupled heat pumps. This paper presents the measured results of the thermal diffusivity of soils (silica, quartzite, limestone, sandstone, and masonry soils) used for the trench backfilling materials of the horizontal ground heat exchanger. To assess this thermal property, we (i) measure the soil thermal conductivities and volumetric heat capacities using dual-probe method and (ii) compare the estimates from the de Vries method of summing the heat capacities of the soil constituents. The results show that the thermal diffusivity tends to increase as dry soil begins Lo wet, but iL approaches a constant value or even decreases as the soil continues to wet. Measurements made by using the dual-probe method agreed well with independent estimates obtained using the single-probe method.

하천수 열원 히트펌프 시스템의 적용 가능성 분석

손병후(Byonghu Sohn),이승언(Seung-Eon Lee) 대한설비공학회 2022 대한설비공학회 학술발표대회논문집 Vol.2022 No.6

This paper analyzed the applicability of the river water source heat pump system. To present applicability, the river water temperature level was compared with the outdoor air and geothermal temperature levels. Next, the performance was compared through a simulation approach for the river water source heat pump and ground source heat pump (GSHP) system applied to a large-scale office building. In order to compare the temperature level, the actual data were applied to the river water and the outdoor air temperature, and the simulation results were applied to the underground circulation water. The results showed that the change in river water temperature throughout the year was similar to the change in outdoor air temperature. Unlike the outdoor air temperature, the difference between the water temperatures on the hourly and daily average was not large. The temperature level of river water was lower during the heating period than that of the ground circulation water and somewhat higher during the cooling period. Finally, the river water source heat pump system was 13.4% lower annually than the GSHP system.

도로 살얼음 방지용 도로 포장체 집열기-보어홀 축열 시스템 고찰

손병후(Byonghu Sohn),우스만 무하마드(Muhmmad Usman),김용기(Yong-Ki Kim) 대한설비공학회 2022 대한설비공학회 학술발표대회논문집 Vol.2022 No.6

Solar energy is undoubtedly an environment-friendly and inexhaustible energy resource for humans. The concept of road pavement solar collector (RPSC)-borehole thermal energy storage (BTES) is an emerging renewable energy technology, which provides an interesting method for solar and geothermal energy utilization. Fluid circulating through the pipes network embedded in the RPSC can capture the solar energy and store it in the BTES for later use. This paper summarizes the major achievements of the existing literature about RPSC, which is one of the major components of the system. Studies have confirmed the feasibility of harvesting solar energy, cooling the pavement, snow melting/de-icing as well as air conditioning of buildings by applying innovative technologies on road pavement. As seasonal energy storage technology is relatively mature at present, most of the literature reviews focus on the influences of variables associated with system behavior as well as the heat transfer processes during snow melting and solar energy collection. Future work should aim to do more urgent issues involved with RPSC application: construction technology, maintenance technology, and long-term performance. Solving these problems can strengthen the theoretical and practical understanding of the RPSC-BTES systems, and lead to more extensive applications.

Effects of Thermal Properties of Bentonite-Based Grouting Material on the Design Length and Performance of Borehole Heat Exchanger

Byonghu Sohn(손병후),Hyoung Jin Kong(공형진),Kyung Chon Min(민경천) 한국신재생에너지학회 2015 한국신재생에너지학회 학술대회논문집 Vol.2015 No.6