• 제목/요약/키워드: compressor oil

검색결과 177건 처리시간 0.031초

An experimental research on temperature accuracy in the refrigerator system with a variable speed compressor

  • Jung, Young-Seok;Hong, Boo-Pyo;Bakhtiar, Agung;Yoon, Jung-In;Choi, Kwang-Hwan
    • 한국태양에너지학회:학술대회논문집
    • /
    • 한국태양에너지학회 2011년도 추계학술발표대회 논문집
    • /
    • pp.264-269
    • /
    • 2011
  • A precision of temperature control in the manufacturing process would be an important factor and become the main key to control production quality. Mostly manufacture machinery used oil as a coolant in their system so an accurate oil temperature control system become an absolute need in industrial field. This paper presents a experiment research to control the oil temperature constant at target point, in this experiment is $35^{\circ}C$ by using an inverter attached in compressor to varying the compressor speed. This control has been completed and tested through an experiment with different heat load of 4kW, 6kW, 7kW, 8kW and 10kW given under temperature constant room conditioned as $25^{\circ}C$. The results had shown the temperature deviation in the refrigerator has around $0.2^{\circ}C$ and the COP is 2.5 gained at 8kW and 10kW.

  • PDF

낮은 오일 농도에서 $CO_2$-Oil 혼합물의 밀도와 점성예측 (Prediction of density and viscosity for $CO_2$-oil mixture at low oil concentration)

  • 윤린
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2008년도 하계학술발표대회 논문집
    • /
    • pp.136-141
    • /
    • 2008
  • Due to environmental concerns $CO_2$ has been reintroduced as a potential candidate to replace HFCs in refrigeration systems since 1990s. In a refrigeration cycle, oil is utilized in lubricating a compressor. However, although oil separators are installed after a compressor oil is prone to leak to the whole system. The mixing of $CO_2$ and oil, even a small amount of oil, the heat transfer performance in heat exchanger deteriorated and the pressure drop inside tube increases. Therefore, it is needed to precisely estimate the mixture thermodynamic properties of $CO_2$-lubricant oil to correctly design a $CO_2$ refrigeration system. The commonly used method in estimating the mixture properties is the mole based weighting model. However, the accuracy of the method can not be assured. In the present study, $CO_2$-lubricant oil mixture properties including viscosity and density were estimated by using the mixture models, based on the equation of state (EOS).

  • PDF

오일 용해도를 고려한 $CO_2$ 트윈 로타리 압축기 성능해석 (Solubility Consideration in Performance Analysis of a $CO_2$ Twin Rotary Compressor)

  • 김우영;안종민;김현진;조성욱
    • 설비공학논문집
    • /
    • 제19권12호
    • /
    • pp.842-849
    • /
    • 2007
  • For a $CO_2$ two-stage twin rotary compressor used for heat pump water heater system, changes of $CO_2$ solubility in PAG oil were investigated along the gas passages from the first stage suction to final discharge. Only slight changes in solubility took place in suction chambers for both of the first and second stages, but for compression chambers, solubility variation ranged from 0.115 to 0.136, and from 0.133 to 0.182, respectively for the first and second stages. Calculation of gas flashing in parts of leakage oil flows and of oil contained in control volumes due to solubility changes was conducted and included in gas pressure calculation. For the second stage, gas flashing amounts to around $5%\sim6%$ for most leakage flows. Cooling capacity, compressor input, and COP obtained by calculation were well compared to the experimental results. Effects of operation speed on the compressor performance was also studied: as the shaft speed increased, adiabatic efficiency decreased rapidly due to increased over-compression loss.

오일부 운전조건 변화에 따른 수소용 다이어프램 압축기의 성능예측에 대한 수치해석 (A Numerical Analysis on a Dependence of Hydrogen Diaphragm Compressor Performance on Hydraulic Oil Conditions)

  • 박현우;신영일;이영준;송주헌;장영준;전충환
    • 한국수소및신에너지학회논문집
    • /
    • 제20권6호
    • /
    • pp.471-478
    • /
    • 2009
  • The specific some types of compressors are appropriate for a use in hydrogen gas station. Metal diaphragm type of hydrogen compressor is one of them, which can satisfy the critical requirements of maintaining gas purity and producing high pressure over 850 bar. The objective of this study is to investigate an characteristics of compression through two-way Fluid-Structure-Interaction (FSI) analysis as bulk modulus and initial volume of oil independently varies. Deflection of diaphragm, oil density, gas and oil pressure were analyzed during a certain period of compression process. According to the analysis results, bulk modulus and initial volume remarkably affected deflection of diaphragm, oil density, gas and oil pressure. The highest gas pressure were attained with the highest bulk modulus of $7e^9\;N/m^2$ and the lowest initial oil volume of 80 cc.

나노입자를 적용한 냉장고 압축기용 오일의 윤활특성 평가 (Performance Evaluation of Nano-Lubricants at Refrigeration Oil)

  • 이광호;황유진;권래언;이재근;김석로;방선욱
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2008년도 하계학술발표대회 논문집
    • /
    • pp.184-188
    • /
    • 2008
  • It has been recognized that friction coefficient decreased with decreasing viscosity of oil in lubrication. In general, the more viscosity decreases, the more wear rate increases due to decrease load carrying capacity. It has been proposed that nano particles in oil decrease friction coefficient and wear rate. The purpose of this study is to apply oil of lower viscosity that mix with nano particles at the compressor used in a refrigerator to decrease friction coefficient keeping Load carrying capacity. Mineral oil of 8 cSt were used and mixed with nano particle. Friction coefficient was evaluated by a disk-on-disk tester. As a result, friction coefficient of nano oil decreased by 90% in comparison with raw oil. These results lead us to the conclusion that nano oil is new plan to raise efficiency of the compressor.

  • PDF

연료전지용 베인 로타리 공기 압축기 설계 (Design of Vane Rotary Air Compressor for Fuel Cell Application)

  • 김현진;이용호;김호영
    • 한국유체기계학회 논문집
    • /
    • 제11권2호
    • /
    • pp.29-37
    • /
    • 2008
  • Air supply is required to the cathode of fuel cells for the provision of oxygen to produce electricity through chemical reaction with hydrogen in the cell, and supplied air should be free of impurities such as oil mist and tiny particles separated from sliding surfaces. Hence, air compressor for fuel cell air supply must be oil-less type and have no severe sliding surfaces inside. This paper introduces the concept of single-vane type rotary air compressor whose structure is particularly suitable for the fuel cell application: sliding action of the vane against the cylinder wall, which causes severe friction in the conventional vane rotary compressors, is made to be prevented by attaching the vane to the driving shaft with the compliant device between the vane and the rotor in this new design. For 2 kW fuel cell application, preliminary design has been carried out, and its performance has been estimated by using computer simulation program: for discharge pressure of 2 bar, the volumetric, adiabatic, and mechanical efficiencies are calculated to be 82.5%, 92.5%, and 96.3%, respectively.

Determination of an Optimum Orbiting Radius for an Oil-Less Scroll Air Compressor

  • Kim, Hyun-Jin;Lee, Yong-Ho;Kwon, Tae-Hun
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • 제16권4호
    • /
    • pp.124-129
    • /
    • 2008
  • Design practice has been made on an oil-less scroll air compressor as an air supply device for a 2 kW fuel cell system where air pressure of 2 bar and flow rate of 120 liter/min are required. Basic structure of the scroll compressor includes double-sided scroll wrap for the orbiting scroll driven by two crankshafts connected to each other by a timing belt. These features can eliminate thrust surface which otherwise would produce frictional heat and jeopardize reliable operation of the orbiting scroll and the scroll element's deformation as well. This study focuses on optimum scroll wrap design; orbiting radius has been chosen as an independent design parameter. As the orbiting radius changes, scroll sizes such as scroll base plate and discharge port diameters change accordingly. Gas compression-related losses and mechanical loss also change with the orbiting radius. With a scroll base plate diameter of 120mm at most and discharge port of at least 10mm, the orbiting radius should be within the range of 2.5-4.0mm. With this range of the orbiting radius, it was estimated by performance analysis that the compressor efficiency reached to a maximum of ${\eta}_c$=96% at the orbiting radius of $r_s$=3.5mm for the scroll wrap height-to-thickness ratio of h/t=5.

스크롤 컴프레서 팁실의 마찰특성 (Friction Characteristics of the Tip Seal in a Scroll Compressor)

  • 정봉수
    • Tribology and Lubricants
    • /
    • 제30권6호
    • /
    • pp.370-377
    • /
    • 2014
  • The basic elements in a rotary-type scroll compressor are two identical spiral scrolls containing refrigerant gas. The pressure variations in the compression pockets of a scroll compressor change the forces acting on the orbiting scroll, and these forces affect the dynamic behavior of the compression mechanism parts. To achieve high efficiency, using a self-sealing mechanism as a tip seal mechanism is very effective. Tip seals, which are placed on top of the scroll wraps, accomplish thrust sealing. This study calculates the friction force between the tip seal and the side plate of a scroll compressor using the numerical model considered in the Reynolds equation. The calculated friction force is verified by an experiment using a pin-on-disk apparatus. A hydraulic servo valve that controls the pressure of the oil hydraulic cylinder applies the normal load for the test, and a DC servo motor controls the sliding velocity of the disk. The friction force and normal load are measured by the force sensors attached to the supporting parts. The results show that the theoretical and experimental results are similar and that the friction is influenced by the viscosity of the oil and the sliding velocity of the scroll.

사이클론 방식 압축기 유분리기의 나선 피치 설계 (DESIGN OF HELIX PITCH OF A CYCLONE TYPE OIL SEPARATOR FOR A COMPRESSOR)

  • 장성일;안준
    • 한국전산유체공학회지
    • /
    • 제19권4호
    • /
    • pp.8-13
    • /
    • 2014
  • A series of numerical simulation has been carried out to study performance of a cyclone type oil separator, which is designed for the compressor of a refrigeration system. Working fluid is R22, which is a typical refrigerant, and mineral oil droplet is supplied. Pitch of the helix is considered as design parameters to make a compact separator. Depending on the helix pitch, separation efficiency varies from 97.5 to 99%, while predicted pressure drop ranges from 5 to 6.5 kPa. Considering both of the pressure drop and separation efficiency, helix pitch of the separator has been designed as 50 mm.

스크롤 압축기의 크랭크축의 동적거동에 관한 수치적 연구 (Numerical Study on the Dynamic Behaviour of a Crank Shaft Used in Scroll Compressor)

  • 김태종;안영재;한동철
    • 대한기계학회논문집
    • /
    • 제17권8호
    • /
    • pp.1940-1950
    • /
    • 1993
  • The theoretical investigation is done on the dynamic behavior of a crank shaft used in a scroll compressor. The compression performance of a scroll compressor is directly influenced by the sealing characteristics between fixed and orbiting scrolls, which is related with the dynamic behavior of a scroll compressor. Analyzing the constrained power transmitting system is came to be of importance, accordingly. The equations of motion and interacting forces of a scroll compressor are derived and solved numerically in this paper. The locus of the crank shaft is also obtained by employing the reaction force caused by the oil film of journal bearing. The results show that the crank shaft of a scroll compressor has considerably stable rotating locus.