• Journal of Mechanical Science and Technology
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• v.20 no.2
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• pp.278-285
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• 2006

The present study has been conducted to simulate dynamics of a gas engine-driven heat pump (GHP) for design of control algorithm. The dynamics modeling of a GHP was based on conservation laws of mass and energy. For automatic control of refrigerant pressures, actuators such as engine speed, outdoor fans, coolant three-way valves and liquid injection valves were PI or P controlled. The simulation results were found to be realistic enough to apply for control algorithm design. The model can be applied to build a virtual real-time GHP system so that it interfaces with a real controller in purpose of prototyping control algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1433-1439
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• 2012

This paper introduces a sensor system based on indoor locations in order to implement the Building Energy Management System. This system consists of a thermopile sensor and an ultrasonic sensor. The sensor module is rotated by $360^{\circ}$ and yawed up-and-down by two electric motors. Therefore, it can simultaneously detect the number and location of the inhabitants in the room. It uses wireless technology to communicate with the building manager or the smart-home server, and it can save electric energy by controlling the lighting system or heating/air conditioning equipment automatically. We also demonstrate the usefulness of the proposed system by applying it to a real environment.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.4
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• pp.275-282
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• 2008

In Korea, air source heat pump system is less efficient than conventional heat source facilities, because the air temperature in winter season is so low that COP of air source heat pump system drops below 3.0. Therefore, the study on the application of heat pump heating and cooling systems is crucial for the efficient popularization of heat pump. In this work, we present the dynamic analysis of energy consumption for the large hospital building by heat resistance-capacitance method. The system simulation of water storage air source heat pump is additionally performed by changing sizes and locations of the hospital building. The computed results show that energy cost of water storage air source heat pump is low, so it is more economical than absorption chiller & heater.

• International Journal of Air-Conditioning and Refrigeration
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• v.6
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• pp.1-13
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• 1998

The basic heat transfer process that occurs in a building can best be illustrated by an electrical circuit network. Present paper reports the dynamic simulation of annual energy consumption in an office building by the thermal resistance capacitance network method. Unsteady thermal behaviors and annual energy consumption in an office building were examined in detail by solving the simultaneous circuit equations of thermal network. The results are used to evaluate the accuracy of the modified BIN method for the energy consumption analysis of a large building. Present thermal resistance-capacitance method predicts annual energy consumption of an office building with the same accuracy as that of response factor method. However, the modified BIN method gives 15% lower annual heating load and 25% lower cooling load than those from the present method. Equipment annual energy consumptions for fan, boiler and chiller in the HVAC system are also calculated for various control systems as CAV, VAV, FCU+VAV and FCU+CAV. FCU+CAV system appears to consume minimum annual energy among them.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.586-589
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• 2009

This paper presents the performance of a water-to-refrigerant type ground source heat pump (GSHP) system installed in a school building in Korea. For analyzing the performance of the GSHP system, we monitored various operating conditions, including the outdoor temperature, the ground temperature, and the input power of the GSHP system. The average cooling coefficient of performance (COP) of the heat pump was found to be 8.5 at 60% partial load condition, while the overall system COP was found to be 5.9. The average heating COP of the heat pump was found to be 6.5 at 45% partial load condition, while the overall system COP was found to be 5.0.

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

• Wind and Structures
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• v.16 no.1
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• pp.61-91
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• 2013

An analytical model of internal pressure response of a leaky and quasi-statically flexible building with a dominant opening is provided by including the effect of the envelope external pressure fluctuations on the roof, in addition to the fluctuating external pressure at the dominant opening. Wind tunnel experiments involving a flexible roof and different building porosities were carried out to validate the analytical predictions. While the effect of envelope flexibility is shown to lower the Helmholtz frequency of the building volume-opening combination, the lowering of the resonant peak in the internal and net roof pressure coefficient spectra is attributed to the increased damping in the system due to inherent background leakage and envelope flexibility. The extent of the damping effects of "skin" flexibility and background leakage in moderating the internal and net pressure response under high wind conditions is quantified using the linearized admittance functions developed. Analytical examples provided for different combinations of background leakage and envelope flexibility show that alleviation of internal and net pressure fluctuations due to these factors by as much as 40 and 15% respectively is possible compared to that for a nominally sealed rigid building of the same internal volume and opening size.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.12
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• pp.828-835
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• 2011

The purpose of this study is to analyze and evaluate the 3 types of indoor ventilation methods such as natural, mechanical, and hybrid ventilation in high-rise building which is affected by stack effect and outdoor air pressure. For the evaluation of the ventilation capacity, CFD simulation was performed in a typical high-rise residential building. The results of the simulations are as follows: 1) Natural ventilation method is not enough to the regulation. 2) In case of mechanical ventilation, congested area is occurred but meets the regulation. 3) In case of hybrid ventilation with stack effect, all the areas of indoor meet the regulation and congested area is reduced. 4) In case of high-rise building, the differences of ventilation rate among houses in the building are not large because the mechanical ventilation is main factor.

• Journal of the Korea Institute of Building Construction
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• v.22 no.2
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• pp.195-205
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• 2022

This paper aims to propose a cost-based mechanical, electrical, and plumbing(MEP) coordination process using building information modeling(BIM). The proposed process can help project participants eliminate identified clashes between the MEP elements, analyze trends relating to MEP costs during the coordination process, and share their findings. MEP quantity-related information extracted through BIM was integrated with the cost database and schedule information. To check the applicability of the proposed process, it was applied to a construction project in South Korea. Through the application of the proposed process, MEP-related cost was reduced.

• Smart Structures and Systems
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• v.16 no.5
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• pp.807-833
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• 2015

While tuned mass dampers are found to be effective in suppressing vibration in a tall building, integrating it with a semi-active control system enables it to perform more efficiently. In this paper a forty-story tall steel-frame building designed according to the Canadian standard, has been studied with and without semi-active and passive tuned mass dampers. The building is assumed to be located in the Vancouver, Canada. A magneto-rheological fluid based semi-active tuned mass damper has been optimally designed to suppress the vibration of the structure against seismic excitation, and an appropriate control procedure has been implemented to optimize the building's semi-active tuned mass system to reduce the seismic response. Furthermore, the control system parameters have been adjusted to yield the maximum reduction in the structural displacements at different floor levels. The response of the structure has been studied with a variety of ground motions with low, medium and high frequency contents to investigate the performance of the semi-active tuned mass damper in comparison to that of a passive tuned mass damper. It has been shown that the semi-active control system modifies structural response more effectively than the classic passive tuned mass damper in both mitigation of maximum displacement and reduction of the settling time of the building.