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R134a용 터보냉동기의 원심압축기 개발 Part 1 : 원심압축기 설계
이용덕,정진희,이현구,윤필현,김길영,Lee, Yongduck,Jeong, Jinhee,Lee, Hyeonkoo,Yoon, Pil-Hyun,Kim, Kilyoung 한국유체기계학회 2000 한국유체기계학회 논문집 Vol.3 No.4
The present study has been conducted to design the high efficiency centrifugal compressor for a R134a turbo-chiller. The centrifugal compressor consists of an impeller with splitters, two vaneless diffusers, a low-solidity vaned diffuser and a volute. A cycle analysis program for a turbo-chiller was developed to obtain compressor design parameters and requirements. We have designed the high efficiency centrifugal compressor by applying the repeated design procedure including a meanline design, a 3D geometry generation and fluid dynamic loading calculations.
김혜림(Hye Rim Kim),송성진(Seung Jin Song),김길영(Kilyoung Kim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5
This study shows the theoretical analysis of surge dynamics in a turbo heat pump. The one-dimensional nonlinear model is developed. This is similar to the previous researches on unsteady analysis in simple compression system. But it is more complicated because the fluids in heat pumps undergo phase changes in heat exchangers and form closed-loop systems. So the two-phase flow effect and feedback effect from evaporator outlet to compressor inlet should be considered. The external conditions such as heat flux from cooling and chilled water are also important. Numerical results are presented to show the surge behavior in a turbo heat pump. It show that there are important parameters which determine the surge characteristics including Greitzer's B parameter and the other related to heat transfer in heat exchangers.
원심형 압축기 파생 설계 인자에 따른 성능 특성에 관한 수치적 연구
신봉근(Bong Gun Shin),이승훈(Seounhoon Lee),조종재(Jongjae Cho),임강수(Kangsoo Lim),김길영(Kilyoung Kim) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11
In this study, the numerical analysis on performance characteristics of a centrifugal compressor in accordance with different derived design parameters, such as flow cut, impeller scaling, and machined Mach number, were performed. Before numerical analysis on the effect of a centrifugal compressor for these parameters, the numerical results were compared with experimental results performed at aero-component test rig at Hanwha Techwin. It is found that the simulated performance results are good agreement with the measured test results. In this study, it is found that derived designed parameters affects centrifugal compressor’s performance caused by the change of Reynolds effect and the friction loss generated within impeller, diffuser and scroll. This study indicates that performance characteristics for each derived design parameter shows different pattern and that it is difficult to predict performance map for various design parameter combination. However, the relative change in performance with relative change in volume flow rate is not depended upon design parameters to reference design performance value. The result shows a new approach idea to predict performance map for design parameters.
원심압축기 임펠러 편심에 따른 성능특성에 대한 유동해석
조종재(Jongjae Cho),신봉근(Bong Gun Shin),이승훈(SeungHoon Lee),조연화(Yeonhwa Cho),김길영(Kilyoung Kim),류시양(ShiYang Ryu) 한국추진공학회 2015 한국추진공학회 학술대회논문집 Vol.2015 No.5
기어드 타입 산업용 원심압축기의 경우, 임펠러의 자중에 의한 쳐짐과 불 기어가 피니언 기어를 미는 힘에 의해 임펠러 편심이 발생한다. 이러한 편심은 임펠러의 동역학 및 성능 특성 변화를 일으킨다. 이 편심에 의한 동특성 현상은 고압 압축기에서 주로 발생한다. 특히, 이 동역학적 불안정성은 임펠러나 축 베어링 파손을 일으킬 수 있다. 임펠러의 파손은 다른 요소부품들의 연쇄적인 손상을 초래하며, 이로 인한 갑작스런 정지 및 상당한 시간과 경제적인 손실을 야기할 수 있다. 따라서 이러한 편심에 의한 임펠러 및 베어링 파손을 방지하기 위해서는 편심에 따른 동역학 및 성능특성 변화에 대한 분석이 필요하다. 따라서 본 연구에서는 압축기 편심에 따른 임펠러에 작용하는 유동 가진력을 전산해석을 통하여 예측하였다. 또한 도출된 결과를 바탕으로 편심량에 따른 동역학적 불안정성과 성능특성을 비교·분석하였다. For an commercial integrally geared centrifugal compressor, the weight of impeller and the pressing force of a bull gear to pinion gear are eccentric to an impeller. The eccentric causes the dynamic and performance characteristics of a compressor. Dynamic instability caused by the eccentricity is mainly generated in the high-pressure compressor. In particular, this instability can cause damage to the impeller and shaft bearing. Damage of the impeller results in damage and failure of other component parts of a compressor, which resulting in sudden stop and in significant time and economic loss. Therefore, analysis of the change in dynamic and performance characteristics of the offset is required in order to prevent the impeller and bearing damage due to such eccentricity. Therefor, in this study, Exciting forces acting on the impeller due to instable flow according to the eccentric were predicted by computational analysis. In addition, comparing the dynamic instability and performance characteristics accoring to eccentricity were compared and analyzed by the numerical results.
閔恒基,金成洙,金佶永 弘益大學校 科學技術硏究所 2002 科學技術硏究論文集 Vol.13 No.-
Electricity receiving facility is the equipment which is composed of a receiving end and a primary transformer, and transformer facility is the transformer equipment connected to the switchboard which distributes the electricity to loading facility. In general, these two facilities are called an electricity receiving-transformer facility. Electricity receiving-transformer facility should be designed well in order to supply high quality electricity in safe and reliable condition. Public electric utilities supply the suitable voltage to the receiving end based on working electric power, then the voltage is changed into a rated voltage of loading facility at the isolated plant power. This facility capacity should be enough in order to supply the electricity to the loading facility, and the expecting power needs should be predictable in order to prevent the trouble from the group of loading facilities in advance. The power loading is carried out through power feeders from receiving end to distribution board. Thickness of power feeders is determined according to the endurable ability for overload or fault current of loading facility, and wrong selected feeders could make an fatal accident to a wide range system because of so many feeders in a building are connected with branch circuits. For a long power feeder, the allowable voltage drop and mechanical intensity should be checked carefully.