• Proceedings of the SAREK Conference
• /
• 2007.11a
• /
• pp.376-381
• /
• 2007

GHP system utilize national gas as a heat source. It reduces electric peak demand in summer and maintains a constant performance in winter by recovering the waste heat from the engine. Although the initial investment cost of GHP is higher than that of EHP, the overall operating cost of GHP is cheaper than of the EHP. In this study, items for dissatisfaction were summarized based on the results of user questionnaire(200 users), and field tests were made for 10 GHP installation places. The measured COP was estimated much lower than the rated COP by the manufacturer mainly due to partial load operation.

• Journal of the Korean Institute of Gas
• /
• v.19 no.1
• /
• pp.1-5
• /
• 2015

In general, natural gas is used as GHP(Gas Engine Driven Heat Pump) fuel. On this study, the influences of different natural gas heating value on GHP were evaluated. As a result of engine test & field test using low heating value gas($9,800kcal/Nm^3$) as fuel, the engine power was reduced slightly, however the performance of start-up, the stability of operation and the characteristics of emission gas were almost similar. So it is considered that the normal operation of GHP is possible without any tuning when the low heating value($9,800kcal/Nm^3$) of natural gas was used as fuel.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.32 no.3
• /
• pp.8-16
• /
• 2003

• Journal of Pharmacopuncture
• /
• v.11 no.3
• /
• pp.47-53
• /
• 2008

Objective: The purpose of this study is to investigate the effects of Ganoderma lucidum herba pharmacopuncture(GHP) on the adipogenesis in 3T3-L1 preadipocytes. Methods: 3T3- L1 preadipocytes were differentiated with adipogenic reagents by incubating for 2 days in the absence or presence of GHP ranging from 1 and 2%. The effect of GHP on cell proliferation of 3T3-L1 preadipocytes was investigated using MTT assay. The effect of GHP on adipogenesis was examined by Oil red O staining and measuring glycerol-3-phosphate dehydrogenase (GPDH) and intracellular triglyceride (TG) content. Results: Following results were obtained from the preadipocyte proliferation and adipocyte differentiation of 3T3-L1. We observed no effect of GHP on preadipocyte proliferation. GHP inhibited adipogenesis, the activity of GPDH and accumulation of intracellular TG content. Conclusions: These results suggest that GHP inhibit differentiation of preadipocyte.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.4
• /
• pp.29-38
• /
• 2009

The GHP(Gas Heat Pump) is an efficient cooling;11eating system in which a compressor is driven by a gas engine and is brodening its application to the facilities such as schools and office buildings. It is difficult to control the GHP system because of slow response, big time constant and time variant system. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probability approach is the most commonly used method to solve time varying harmonics. This paper provides an in depth analysis on harmonics field measurement of the GHP loads, harmonic assessment by me 61000-3-2, and harmonic simulation and harmonic filter application using EDSA program for the case study system.

• Transactions of the KSME C: Technology and Education
• /
• v.3 no.1
• /
• pp.15-21
• /
• 2015

In this paper a prediction method of GHP performance is proposed for increasing design accuracy. Two compressors with different capacity and 2311cc gas engine are used for prediction and the target capacity of GHP is 25HP. For predicting GHP performance at first the operation points are randomly selected and then as compared with compressor performance date and heat exchanger characteristic, more accurate operating points are decided through recursive calculation. Lastly engine performance date is used for calculating gas consumption volume. Predicting heating mode performance of GHP, evaporator is separated to the two section of absorbing heat in outdoor air and in engine. From the experimental results, it was found that the simulation model is good for the predicting GHP efficiency and the difference of predicted and measured efficiency is less than 5%.

• 월간 기계설비
• /
• s.163
• /
• pp.85-109
• /
• 2004

가스난방기인 GHP의 인기가 급부상하면서 1995년 선을 보인 후 GHP시장이 올 한해 보급대수만 3천5백대에 달할 것이라는 소식이며 이는 지난해보다도 3배이상 늘어난 수치이다. GHP가 각광을 받는 것은 청정연료인 가스를 사용하고 우수한 냉$\cdot$난방효과를 얻을 수 있는 데다 기기 수명이 길고 유지보수가 간단하게 이루어지는 등 장점이 많다는 점에서다. 또한 친환경적이라는 측면에서 매우 긍정적이며 여름철 전력난 해소에도 기여한다는 점에서 국가경제에도 매우 크다고 할 수 있다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.3
• /
• pp.243-249
• /
• 2005

The present study has been conducted to simulate dynamics of a gas engine-driven heat pump(GHP) for design of control algorithm. The dynamic 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 fan, coolant three-way valves and liquid injection valve were PI or P controlled. The simulation results showed physical behavior that is realistic enough to apply for control algorithm design.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.06a
• /
• pp.373-376
• /
• 2006

본 연구의 목적은 동해 울릉분지의 제4기 후기 퇴적물 내의 유기물, 공극수와 메탄의 특징 및 상호작용을 규명하는데 있다. 연구지역에서 채취한 코어퇴적물을 원소 분석한 결과 C/N 및 C/S 비(wt. %)는 퇴적물 내 유기물이 주로 해양조류 기원을 가지고, 일반적인 해양 또는 정체 환경에서 퇴적되어Tdam을 지시한다. 그러나 Rock-Eval 열분석 결과는 유기물 기원이 육상식물(Type III)이고, 열적 성숙단계가 미성숙단계임을 보여준다. 이러한 원소분석과 열분석간의 상반된 결과는 유기물이 침강하는 동안 또는 퇴적 후 이루어진 강한 산화작용에 기인한 것으로 추정된다. 퇴적물 내 공극수의 황산염 농도가 퇴적물의 심도가 증가할수록 감소하며, 감소하는 경향은 크게 두 가지 (적선성, concave down)로 나누어진다. 이는 모든 코어에서 황산엽 환원작용이 일어나고 있음을 지시한다. 또한 직선선의 황산엽농도 구배는 무산소 메탄 산화작용(AMO)의 전형적인 특징이다. 황산염 농도의 수직적 구배를 이용하여 SMI(sulfate-methane interface) 심도를 계산하면, 남부울릉분지의 코어 (03GHP-01, 03GHP-02; <3.5mbsf)가 북부울릉분지 코어(01GHP-05, 01GHP-07, 03GHP-03, 03GHP-04, 03GHP-05; > 6mbsf)보다 낮은 값을 갖는다. 위와 같은 SMI 심도차는 메탄의 상부 분산량과 밀접한 관련있는 것으로 추정된다. 메탄가스의 탄소 안정동위원소 $({\delta}^{13}C)$ 분석값들은 -83.5%o에서 -69.5%o의 범위를 가지고 있고, 이산화탄소 환원작용($CO)_2$ reduction)에 의한 생물 (biogenic) 기원임을 지시한다.

• Journal of the Korean Society of Industry Convergence
• /
• v.23 no.6_2
• /
• pp.917-926
• /
• 2020

Friction mechanisms is a very important role in the industrial machinery. However, many experiments have been conducted to reduce the loss of energy resources and parts used due to friction because the friction force adversely affects parts, efficiency, noise, and the like of the power unit. Therefore, in this study, the friction coefficient according to the characteristics of the lubricant was measured to find out which Grease Lubricant maintains the low friction coefficient without being most affected by external conditions. A total of five grease lubricants were tested in this study: GHP CAL 301, GHP EP 2, GHP KG 10, GHP HPG 2, and GHP HTG 2. And the friction coefficient was conducted by changing the load conditions (2, 4, 6, 8, 10N) and rotational speed (24, 48, 67, 86, 105, 124, 143, 162vrpm) using a pin-on-disk wear test system. Also, duty number were calculated. As a result, it was confirmed that in all grease lubricants, the speed did not significantly affect the friction coefficient, and it was confirmed that in all lubricants, the size of the friction coefficient decreased as the load increased from a small load to a large load. In addition, it was determined from the experimental results that GHP EP 2 is the most suitable as a grease lubricant and GHP CAL 301 is not the most suitable.