• Title/Summary/Keyword: R-407C

Search Result 141, Processing Time 0.025 seconds

A study on prediction of oil concentration in the R-407C and R-410A refrigeration system (대체냉매 R-407C와 R-410A를 사용하는 냉동시스템의 오일농도 예측에 관한 연구)

  • 이종문;김창년;박영무
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.11 no.3
    • /
    • pp.384-390
    • /
    • 1999
  • A vibrating U-Tube decimeter has been evaluated as a sensor for measuring the concentration of oil in the liquid line of a refrigeration system. Calibration and performance tests were conducted under simulated liquid-line conditions for R-407C/POE oil and R-410A/POE oil mixtures in oil concentration from 0 to 15 weight percent. Test temperatures ranged from 20 to 5$0^{\circ}C$. As a result of test, oil concentration correlations are presented in terms of specific gravity at each constant temperature. These equations enable to predict the oil concentration without any extraction of the mixture, and can be applied for R-407C/POE oil and R-410A/POE oil mixtures.

  • PDF

Prediction and Experiment of Pressure Drop of R22, R407C and R410A on Design Conditions of Condenser (응축기의 설계조건에서 R22, R407C, R410A의 압력강하 예측 및 실험)

  • 김창덕;박일환;이진호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.16 no.1
    • /
    • pp.42-53
    • /
    • 2004
  • An experimental study on the refrigerant-side pressure drop of slit fin-tube heat exchanger has been carried out. A comparison was made between the predictions of previously proposed empirical correlations and experimental data for the pressure drop on design conditions of condenser in micro-fin tube for R22 and its alternatives, R407C (R32/125/134a, 23/25/52 wt.%) and R410A (R32/125, 50/50 wt.%). Experiments were carried out under the conditions of inlet refrigerant temperature of 6$0^{\circ}C$ and mass fluxes varying from 150 to 250 kg/$m^2$s for R22, R407C and R410A. The inlet air conditions are dry bulb temperature of 35$^{\circ}C$, relative humidity of 40% and air velocity varying from 0.68 to 1.43 m/s. Experiments show that pressure drop for R410A and R407C were 17.8∼20.2% and 5∼6.8% lower than those of R22 respectively for the degree of subcooling of 5$^{\circ}C$. For the mass fluxes of 200∼250 kg/$m^2$s, the deviation between the experimental and predicted values for the pressure drop was less than $\pm$20% for R22, R407C and R410A.

Heat transfer characteristics of R - 407C condensing inside smooth horizontal tubes (냉매 R-407c의 수평평골 응축관내 열전달특성에 관한 연구)

  • 오후규;문정욱;노건상
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.21 no.2
    • /
    • pp.144-156
    • /
    • 1997
  • Experimental results for forced convection heat transfer of pure refrigerant and nonrefrigerant mixtures during condensing inside horizontal smooth tubes, double pipe heat exchanger of 7.5 mm ID and 4 000 mm long inside tube, are presented. Pure refrigerant R - 22 and R - 407 c, the mixture of R - 32 + R - 125 + R - 134a (23/25/52, wt %) are used as the test fluids. The ranges of parameters are $114.3{\sim}267.1 kg/(m^2 {\cdot} s)$ of mass velocity, <0$\sim$1.0 of quality. The vapor pressure, vapor temperature and tube wall temperature were measured. Using these data, the local and average heat transfer coefficients for the condensation are obtained. At the same given experimental conditions, the condensation heat transfer coefficients for NARMs R - 407c were lower than those for the pure refrigerant of R - 22. Local heat transfer characteristics for R - 407c were different from pure refrigerant R - 22. The condensaheat transfer coefficients for R - 407c and R - 22 increased with mass velocity. Based on the data a prediction method was presented for the calculation of dimensionless average heat transfer coefficient.

  • PDF

Condensation heat transfer characteristics of R-22 and R-407C in micro-fin tubes (마이크로핀관에서의 냉매 R-22, R-407C의 응축전열특성에 관한 연구)

  • Roh, Geon-Sang
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.32 no.1
    • /
    • pp.50-56
    • /
    • 2008
  • Experimental results for forced convection condensation of Refrigerant-22 and ternary Refrigerant-407C(HFC-32/125/134a 23/25/52 wt%) which is being considered as a substitute R-22 inside a horizontal micro-fin tube are presented. The test section was horizontal double-tube counterflow condenser with a length 4,000 mm micro-fin tube, having 8.53 mm ID, 0.2 mm fin height and 60 fins. The range of parameters of mass velocity were varied from 102.1 to 301.0 kg/(m2.s) and inlet quality 1.0. At the given experimental conditions. the average heat transfer coefficients for R-407C were lower than that for R-22 at a micro-fin tube. Over the mass velocity range tested. the PF(penalty factor) for R-22, R-407C were lower than the increasing ratio of heat transfer area by fins, and the EF(enhancement factor) for R-22, R-407C were higher than the increasing ratio of heat transfer area by fins.

An Experimental Study on Condensation Characteristics at Various Condensation Pressure of R407C (응축압력 변화에 따른 R407C의 응축특성에 관한 연구)

  • 전창덕;장경근;김창덕;이진호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.15 no.3
    • /
    • pp.230-238
    • /
    • 2003
  • R407C is considered as alternative refrigerant of R22 for air conditioners. Experimental investigation is made to study the condensation heat transfer characteristics of slit fin-tube heat exchanger using alternative refrigerant, R407C. Experiments are carried out at condensation pressure of 2110 kPa and 1943 kPa with the degree of superheat of 1$0^{\circ}C$ and mass flux varying from 150 to 250 kg/$m^2$s for refrigerant side. The inlet air condition is dry bulb temperature of 35$^{\circ}C$, relative humidity of 50% and air velocity varying from 0.8 to 1.6 m/s. Experiments show that pressure drop gets smaller at a higher condensation pressure especially when condensation pressure is raised from 1943 to 2110 kPa. Heat transfer rate gets smaller at a lower condensation pressure in the range of experimental condition.

Effects of Refrigerant Oils and Molecular Sieve on Air Conditioner using Alternative Refrigerant (대체냉매를 사용한 에어콘에서 합성오일과 건조제(M/S)의 영향)

  • Choa, S.H.;Hong, C.K.;Kim, C.K.;Yoon, B.;Kang, S.C.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.8 no.4
    • /
    • pp.473-483
    • /
    • 1996
  • To protect the ozone layer, R22 will be replaced with HFCs. R407C is a leading candidate as alternative refrigerant for air conditioner due to its similar thermodynamic characteristics with R22. In replacing R22 with R407C, the compatibility with lubricating oil is of major concern. Polyol ester (POE) oil among the synthetic oils is considered to be the best lubricant for use with R407C because of good electrical properties and miscibility. However, lubricating ability of mixture of R407C/POE oil is lower than that of R22/mineral oil due to the production of acid by hydrolysis which causes corrosive wear. Therefore, to minimize water content, it is needed to develop a molecular sieve desiccant which is compatible with R407C and ester oil. This paper discusses (1) the change of properties of POE oil when current molecular seive is used, (2) the effects of POE oils and additives on durability of compressor. Through compressor life test and bench wear test, it was found that inadequate use of POE oils and additives may promote the deteriation of molecular sieve, resulting in decrease of durability of compressor.

  • PDF

Experimental study for the pressure drop of R-22 and R-4O7C during the condensation in the micro-fin tubes (마이크로핀관내에서 R-22와 R-4O7C의 응축압력강하 특성에 관한 실험적 연구)

  • Roh, Geon-Sang
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.31 no.6
    • /
    • pp.715-722
    • /
    • 2007
  • Experiments were conducted for the investigation of pressure drop inside horizontal micro-fin tubes during the condensation of R-22 and ternary refrigerant. R-407C(HFC-32/125/134a 23/25/62 wt%) as a substitute of R-22. The condenser is a double-tube and counterflow type heat exchanger which is consisted with micro-fin tubes having 60 fins with a length of 4000mm, outer diameter of 9.53mm and fin height of 0.2mm. The mass velocity varied from 102.1 to $301.0kg/(m^2{\cdot}s)$ and inlet quality was fixed as 1.0. From the experimental results. the pressure drop for R-407C was considerably higher than that for R-22. The value of PF(penalty factor) for both of refrigerants was not bigger than the ratio of micro-fin tube area to smooth tube area. Based on the experimental data. correlation was Proposed for the prediction of frictional pressure drop during the condensation of R-22 and R-407C inside horizontal micro-fin tubes.

Condensation Heat Transfer of R22, R407C, and R410A in Slit Fin-and-Tube Heat Exchanger

  • Jeon, Chang-Duk;Lee, Jin-Ho
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • v.11 no.4
    • /
    • pp.188-198
    • /
    • 2003
  • R410A and R407C are considered to be alternative refrigerants of R22 for the air-conditioners. An experimental study is carried out to investigate the effect of the change of mass flow rate on the characteristics of heat transfer and pressure drop in three row slit finned-tube heat exchanger for R407C, R410A and R22. R407C, a non-azeotropic refrigerant mixture, exhibited a quite different condensation phenomenon from those of R22 and R410A and its condensation heat transfer coefficient was much lower than that of R22 and R410A. On the other hand, the condensation heat transfer coefficient of R410A, near-azeotropic refrigerant mixture, was a little higher than that of R22. R410A also showed the lowest condensation pressure drop across the test section. For all refrigerants, the condensation heat transfer coefficient and pressure drop increase as the mass flux increases. The condensation heat transfer coefficient correlation proposed by Kedzierski shows the best agreement with the experimental data within $\pm$20%.

Investigation on the Selection of Capillary Tube for the Alternative Refrigerant R-407C

  • Kim, Chang-Nyeun;Park, Young-Moo
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • v.8 no.1
    • /
    • pp.40-49
    • /
    • 2000
  • The capillary tube performance for R-407C is experimentally investigated. The experimental setup is a real vapor-compression refrigerating system. Mass flow rate is measured for various diameter and length while inlet pressure and degree of subcooling are changed. These data are compared with the results of a numerical model. The mass flow rate of the numerical model is about 14% less than the measured mass flow rate. It is found that mass flow rate and length for R-407C are less than those for R-22 under the same condition. Based on this experimental study and the numerical model, a set of design charts for capillary tube of R-407C is proposed.

  • PDF

An Experimental Study on Condensation Characteristics of Slit Fin-tube Heat Exchanger Using Alternative Refrigerants, R407C and R410A (대체냉매 R407C 및 R410A를 이용한 슬릿휜-관 열교환기의 응축특성에 관한 연구)

  • 전창덕;장경근;강신형;이진호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.14 no.9
    • /
    • pp.706-716
    • /
    • 2002
  • R410A and R407C are considered to be alternative refrigerants to R22 for the air-conditioners. Experimental investigation is made to study the condensation heat transfer characteristics of slit fin-tube heat exchanger using alternative refrigerants R410A and R407C. R407C, a non-azeotropic refrigerant mixture, exhibited a quite different condensation phenomenon from those of R22 and R410A and its condensation heat transfer coefficient was much lower than that of R22 and R410A. Between the R22 and R410A, the condensation heat transfer coefficient of R410A, near-azeotropic refrigerant mixture, was a little higher than that of R22. R410A also showed the lowest condensation pressure drop across the test section. For all refrigerants, the condensation heat transfer coefficient and pressure drop increase as the mass flux increases.