• 한국산학기술학회논문지
• /
• 제19권8호
• /
• pp.312-321
• /
• 2018

한국의 수요자원(Demand Response, DR) 거래시장은 자연재해 또는 예기치 않은 발전소 사고로 인한 전력수급 위기 시 최대수요를 억제하며, 발전소 건설비용 절감 및 운영예비력 확보를 위한 목적으로 운영되고 있다. 수요자원 거래시장에 참여한 수용가는 전력거래소로부터 수요 감축 1시간 전 급전지시를 통보 받으며, 요청된 수요자원 감축을 통하여 기본급과 실적금을 정산 받는다. 본 논문에서는 냉각 시스템과 ESS을 갖춘 수용가가 계시별요금제와 수요자원 거래시장에 동시 참여 시, 최적 운영계획 수립을 위한 DR 에너지관리 알고리즘을 제안 하였다. 제안된 알고리즘은 주위온도 예측오차가 있는 전일 운영 스케줄링과 DR 운영일 리스케줄링의 두 가지 운영 스케줄링으로 구성된다. 전일 운영 스케줄링의 경우, 냉각 시스템, ESS의 운영스케줄링은 과거 주위온도 데이터를 기반으로 생성된 주위온도 시나리오와 불확실한 DR감축 시나리오에 의해 결정된다. 또한 DR 운영일에 대한 리스케줄링은 수용가의 DR 수익과 건물내부 열괘적성이 보장되며 제안된 방법은 혼합정수 선형 프로그래밍(Mixed Integer Linear Programming, MILP)에 의해 기대 에너지 비용을 최소화한다.

• 한국지열·수열에너지학회논문집
• /
• 제10권1호
• /
• pp.7-13
• /
• 2014

This study intends to analyse the economical aspect of a GSHP(Ground Source Heat Pump) system compared to the conventional system which is consisted with a boiler and a chiller. This study has simulated four systems in Incheon. It developed and analyzed for applications in a residential and an office building which was based on the hourly EPI(Energy Performance Index, $kWh/m^2yr$). Case 1 is utilizing a boiler and a chiller to meet heating and cooling demand of a house. Case 2 is utilizing the same conventional set up as Case 1 of a office. Case 3 is summation of Case 1(house) and 2(office) systems and loads. And Case 4 is utilizing a GSHP to meet the combined loads of the house and office. The method of the economic assessment has been based on IEA ECBCS Annex 54 Subtask-C SPB(Simple Payback) method. The SPB calculated the economic balanced year of the alternative system over the reference system. The SPB of the alternative systems (GSHP) with 10%, 30% and 50% initial incentive has been calculated as 9.38, 6.72 and 4.06 year respectively while the SPB without initial incentive of systems was 10.71 year.

• 한국지열·수열에너지학회논문집
• /
• 제17권3호
• /
• pp.30-40
• /
• 2021

This paper compares the annual energy performance of four different types of air-conditioning systems in a medium-sized office building. Chiller and boiler, air-cooled VRF, ground-source VRF, and ground-source heat pump systems were selected as the systems to be compared. Specifically, the energy performance of the GSHP system and the ground-source VRF system were compared with each other and also with conventional HVAC systems including the chiller and boiler system and air-cooled VRF system. In order to evaluate and compare the energy performances of four systems for the office building, EnergyPlus, a whole-building energy simulation program, was used. The EnergyPlus simulation results show that both the GSHP and the ground-source VRF systems not only save more energy than the other two systems but also significantly reduce the electric peak demand. These make the GSHP and the VRF systems more desirable energy-efficient HVAC technologies for the utility companies and their clients. It is necessary to analyze the impact of partial load performance of ground-source heat pump and ground-source VRF on the long-term (more than 20 years) performance of ground heat exchangers and entire systems.

• 설비공학논문집
• /
• 제22권12호
• /
• pp.852-858
• /
• 2010

In an absorption chiller, solution is circulated by a solution pump with an inverter to vary flow rate depending on operating conditions. For optimal operation, the solution level in the high temperature generator should be kept constant. However, a sensor for measuring continuous level is not available because of varying solution concentration. Instead, level switches are used and hence feedforward control associated with limit checking is a common practice. In the study, inverter frequencies are estimated from a dynamic simulation model and pump performance. Designed frequencies are compared with those implemented in real chillers. It was found that the frequencies used in real chillers are larger than those needed in circulation flow rates. It was intended to prevent system shut-off caused by dry-out. However, it is necessary to minimize the excessive frequency setting in order to reduce frequent pump stops and the range of solution level for continuous pump operation.

• 설비공학논문집
• /
• 제23권9호
• /
• pp.633-638
• /
• 2011

Increasing demand for comfortable indoor environment and air-conditioning demand is also increasing. Building energy consumption in university which is made up of many different kinds factor was researched. Central control air-conditioning systems are being replaced with individually controlled air-conditioning system. The amount of growth of electricity consumption is due to the increasing demand of EHP. Conversely, the demand for absorption chiller-heater is shrinking. Winter and in summer a lot of electricity and gas usage. On the other hand, showed less energy in spring and autumn. Increase the amount of electricity than the degree of decline in gas consumption was higher. Can be considered as transitional phenomena. Because EHP and the absorption chiller-heater are used at the same time in some of the buildings. To use energy efficiently is needed additional research about environmental impact, economic evaluation.

• 설비공학논문집
• /
• 제25권7호
• /
• pp.392-397
• /
• 2013

To fulfill the demands concerning energy efficiency for zero energy buildings, various technologies of architects and engineers are required. This study aims to estimate the thermal performance of heat source equipment in which part load characteristics are considered in an office building. Overestimation of heat source equipment was reviewed through literature survey, and heating and cooling loads depending on the capacity and division of the equipment were analyzed through a simulation program (DOE-2.1E). The conclusions gained from this study are as follows; 1) The more the division of equipment, the less the heating and cooling energy consumption. 2) When a large item of equipment is divided into two small items of equipment, the optimum application rate showed as 5:5 for chiller, and 7:3 for boiler, respectively.

• 설비공학논문집
• /
• 제23권11호
• /
• pp.705-710
• /
• 2011

Fault detection has to be proceeded by steady state filtering to get rid of transient effect associated with thermal capacity. Coefficient of variance (COV), ratio of standard deviation devided by moving average, was employed as steady-state filter. Engine speed and refrigerant pressures were selected as parameters representing system dynamics. The filtered values were registered as members of steady-state DB. They were found to show good functional relationship with ambient temperature. The relationship was fitted with a second order polynomial and the distribution bounds of the data around the fitted curve were expressed by visual inspection because of varying average and random data interval. Fault data were compared with the steady-state data obtained during normal operation. The fault data were easily isolated from the fault-free one. To make such isolation reliable, tests to construct good DB should be designed in a systematic way.

• 한국지열·수열에너지학회논문집
• /
• 제6권2호
• /
• pp.1-7
• /
• 2010

The objective of this study is to find the optimal control algorithm of a hybrid Plant, which is combined by renewable energy plant of the GSHP(Geothermal Source Heat Pump) and the normal plant (Chiller, boiler). The work presented in this study was carried out in the EnergyPlus(Version 2.0). The EnergyPlus was modified in order to simulate the hybrid plant. The plant system was controlled by the load-range-based operation in which schemes select a user specified set of equipment for each user specified range of a particular simulation condition. In the use of the load-range-based operation, four kind of control cases were defined and simulated in order to obtain the optimal control algorithm of the hybrid plant. The result showed that the Case 2 was the optimal control algorithm which used the GSHP as a base operating plant and the normal plant as an assistant operating plant. Even though the normal plant was operated in full load and the renewable energy plant of the GSHP was operated in partial load, the annual energy consumption of the normal plant was larger than that of the GSHP plant.

• 설비공학논문집
• /
• 제17권8호
• /
• pp.746-753
• /
• 2005

Adsorption chillers have been receiving considerable attentions as they are energy-saving and environmentally benign systems. In order to evaluate adsorption rates, experiments were performed in the batch type adsorption apparatus. Three types of silica gels were investigated under an assortment of experimental conditions that are representatives of the actual operating environments in the adsorber of adsorption chillers. Experimental results revealed the effects of silica gel particle size, bed temperature, and fin pitch of fin tube on the adsorption rate. The $0.25\~1.18mm$ particle size of silica gel with high adsorption rate was selected as a suitable adsorbent. The measured adsorption rate became bigger with decreasing particle size. From the comparison of adsorption rate, it is found that the fin tube has about $21\%$ higher value than that of the bare tube. The effect of heat and mass flux is found to be more significant in the fin tube than in the bare tube.

• 한국산업정보학회:학술대회논문집
• /
• 한국산업정보학회 2000년도 추계공동학술대회논문집
• /
• pp.609-616
• /
• 2000

캐리어주식회사는 1985년 대우와 미국의 Carrier사가 50:50으로 설립한 Joint Venture로서 냉난방기 전문 제조 및 판매 회사이다. 1991년 미국 Carrier사가 85%의 지분을 확보함으로써 미국 Carrier사가 직접 경영을 하게 되었으며, 2000년에는 100% 지분을 확보하고 회사명도 대우캐리어주식회사에서 캐리어주식회사로 변경되었다 당사의 주요생산 품목은 룸 에어컨, 패키지 에어컨, Rotary Compressor 그리고 Chiller, AHU 등 System 제품이다. 공장은 광주광역시 하남공단에 위치하고 있으며 종업원은 약 1400명이다.(중략)