• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.8 no.2
• /
• pp.61-69
• /
• 2012

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($1,210m^2$) 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.26 no.6
• /
• pp.257-262
• /
• 2014

This paper describes an experimental study for heating performance that can be used in R-134a automobile heat pump systems. The heat pump system is widely studied for heating system in zero-emission vehicles to attain both the small power consumption and the effective heating of the cabin. This paper presents the experimental results of the influence on heating capacity and coefficient of performance of heat pump system. Tests were performed with different sizes of internal and external heat exchangers, and refrigerant flow rate was also considered in two-way flow devices. In addition, the heat, air, and water sources with the heat pump system were examined. The experimental results with the heat pump system were used to analyze the impact on performances. The best combination of performance was A-inside heat exchanger, B-outside heat exchanger, and B-flow device, respectively. In addition, a water heat-source was found to give roughly 40% of better performance than an air heat-source heat pump system.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.903-908
• /
• 2006

Building energy simulation has become a useful tool for predicting cooling, heating and air-conditioning loads for facilities. It is important to provide building energy performances feed back to the mechanical and electrical system operator and engineer for energy conservation and maintenance of building. From this research, we set up the typical weather data of location, basic description of building, geometric modelling data and the specification of Installed primary HVAC system for establishing the simulation model about energy consuming that take place in multipurpose building complex. The simulation tool of building energy - EnergyPlus (DOE and BLAST based simulation S/W), it has been used and accomplished calculations and analyses for evaluating the effect of the system types and operating condition of central HVAC plant on the building energy consumption. In this paper, we offer comparison and simultaneous results those involve electricity consumption pattern and amount between actual operation versus EnergyPlus simulation to the object building during summer season.

• Journal of Hydrogen and New Energy
• /
• v.31 no.6
• /
• pp.637-645
• /
• 2020

In this paper, entransy analysis is carried out for combined heat and power (CHP) generation system driven by low-grade heat source compared with energy and exergy analyses. The system consists of a regenerative organic rankine cycle (ORC) and an additional process heater in a series circuit. Special attention is paid to the effects of the turbine inlet pressure, source temperature, and the working fluid on the thermodynamic performance of the system. Results showed that the work efficiency of entransy is higher than that of energy but lower than that of exergy, wheress the process heat efficiency of entransy is lower than that of energy but higher than that of exergy. Entrance analysis showed the potential to complement the exergy analysis in the optimal design of the energy system.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.17 no.2
• /
• pp.11-19
• /
• 2021

In this study, combined heat source heat pump system was implemented with 4 single heat source heat pumps each applied with a geothermal source and a water source. Five cases (Case1~Case5) were configured to conduct a performance comparison and analysis of the combined heat source heat pump system. First of all, as a result of analyzing the heat source, the case when 4 ground heat sources were applied (Case1) showed a uniform EST(Entering Source Temperature) distribution throughout the year since it is less affected by outside air compared to the case when 4 water heat sources were applied (Case5). In both winter and summer, the ground heat source maintained higher EST than the water heat source. Therefore, the system with high ratio of geothermal sources is advantageous for heating, and with high ratio of water heat sources is advantageous for cooling.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.18 no.4
• /
• pp.365-388
• /
• 1989

열병합발전시스템은 엔진 또는 가스터빈구동의 열병합발전설비이며, 전력과 열을 동시에 이용함으로써 높은 총합열효율이 기대되는 열원시스템이다. 그 경제성은 전력과 열의 수요가 년간을 통해서 안정하게 존재할 것이 필요조건으로 된다. 본보는 일년간의 운전기록을 사용하여 현재 가동하고 있는 시스템의 특성, 전력수요와 열부하의 실태를 분석하여 개략적으로 설명하는 것이다. 해석에 사용된 자료는 시간단위의 계획치, 적산치이며, 데이터입력후의 인산, 통계, 도표 작성등은 전부 전산기시스템으로써 처리하였다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2002.11a
• /
• pp.53-58
• /
• 2002

선진국에서는 산업체의 1차 에너지소비가 전체 에너지소비의 약 30~40%이고, 이 에너지의 약 70~80%가 공정용 열에너지로 사용되고 있다. 이러한 공정용 열의 온도범위를 파악하는 것은 매우 중요하지만 산업공정의 다양성 때문에 평가하기에는 많은 어려움이 따른다. 그러나 일반적으로 산업체 열에너지의 60% 이상은 30$0^{\circ}C$ 이하의 온도이며, 약 20~30%는 15$0^{\circ}C$ 이하이다.(중략)

• Proceedings of the SAREK Conference
• /
• 2006.11a
• /
• pp.59-59
• /
• 2006

• Proceedings of the SAREK Conference
• /
• 2006.11a
• /
• pp.10-10
• /
• 2006

• Proceedings of the KIEE Conference
• /
• 2007.11b
• /
• pp.305-307
• /
• 2007

본 논문은 지역냉난방 집단에너지사업의 열원다원화를 위한 미활용폐열의 연계공급방안의 수립을 통한 지역냉난방 집단에너지사업의 개선방안을 제시하였다. 산업단지에서 발생되는 폐열에 대한 효율적인 회수 메커니즘과 연계공급 및 활용방안에 대한 전반적인 검토를 통한 미래 산형 에너지공급시스템의 근간이 될 집단에너지사업의 장기적 발전을 도모코자 하였다.