端面機械密封裝置的熱傳遞畢業(yè)論文外文翻譯（英文）

1、International Journal of Thermal Sciences 48 (2009) 781–794www.elsevier.com/locate/ijtsHeat transfer in a mechanical face sealNoël Brunetière ?, Benoit ModoloUniversité de Poitiers, UMR CNRS 6610, Laborato

2、ire de Mécanique des Solides, S.P.2M.I., BP 30179, 86962 Futuroscope Chasseneuil Cedex, FranceReceived 28 August 2007; received in revised form 18 March 2008; accepted 17 May 2008Available online 20 June 2008Abstrac

3、tThis paper presents a numerical analysis of heat transfer in an experimental inner pressurized mechanical face seal, using CFD. The configura- tion is similar to the laminar flow between a static and a rotating disc bou

4、nded by a co-rotating sidewall. A series of simulations allow the authors to propose a correlation for the global Nusselt number for the rotating ring and the static disc. The Nusselt number is a function of the Reynolds

5、 number of the flow and the Prandtl number, as well as of the ratio of the fluid and material thermal conductivities. This last conclusion arises from the fact that the heat source is located in the contact between the r

6、otor and the stator and depends on the temperature distribution in the solids. The cooling oil flow appears not to affect the Nusselt number. The numerical results were validated by comparison with measurements carried o

7、ut on the experimental seal by means of an infrared camera.© 2008 Elsevier Masson SAS. All rights reserved.Keywords: Convective heat transfer; Infrared thermography; Rotor–stator; Mechanical Face Seal; CFD (Computat

8、ional Fluid Dynamic)1. IntroductionMechanical face seals are used to seal pressurized fluids in rotating machines such as pumps, compressors and agitators, where pressure, temperature and velocity conditions prevent the

9、use of elastomeric seals. These seals are basically composed of a rotating part mounted on to the shaft and a stationary part fixed to the housing. The two parts are maintained in contact by the action of springs and of

10、the pressurized fluid (Fig. 1). Good operating conditions are achieved when the seal faces are partially separated by a thin lubricating fluid film (a fraction of micrometer), avoiding wear on the faces while limiting le

11、akage rate to an acceptable value. According to Lebeck [1], the behaviour and performance of a mechanical face seal are influenced as much by the thermal behaviour of the seal as by any other factor. Indeed, the dis- sip

12、ated power due to viscous friction and asperities contacts in the sealing interface leads to a significant increase in tem-* Corresponding author. E-mail address: noel.brunetiere@lms.univ-poitiers.fr (N. Brunetière)

13、.Fig. 1. Example of mechanical face seal.perature in the fluid film and in the contiguous solids [2,3]. Consequently, the lubrication conditions are modified because of fluid viscosity variation, thermal distortions of t

14、he seal rings and possible phase change. A possible effect of these variations is a drastic increase in leakage rate or seal failure. This is why there have been many studies dealing with thermal effects in recent decade

15、s. A brief review is presented in [4]. The main1290-0729/$ – see front matter © 2008 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.ijthermalsci.2008.05.014N. Brunetière, B. Modolo / International Jour

16、nal of Thermal Sciences 48 (2009) 781–794 783In all the studies dealing with heat transfer around a mechan- ical face seal, no author set out to develop a Nusselt number correlation. Moreover, the authors were comparing

17、their find- ings with empirical formulas obtained in flow involving a uni- formly heated rotating cylinder. There is a significant difference here from mechanical face seals, where the heat source is lo- cated in the sea

18、ling interface. Thus the Nusselt number also depends on the temperature distribution in the seal rings, this being a function of the material properties. In addition, no stud- ies were carried out on inner-pressurized me

19、chanical face seals, a less widespread technology where the sealed fluid is located between the rotating shaft and the seal rings. The aim of the present work is to analyze numerically and, to a lesser extent, experiment

20、ally a mechanical face seal. This experimental seal was essentially designed to validate numerical models of the contact behaviour through infrared temperature measurements [3,4] and is thus quite different from industri

21、al mechanical face seals. More particularly, the seal is inner-pressurized and op- erates with a highly viscous mineral oil resulting in laminar flow. Moreover, the shaft does not pass trough the seal chamber leading to

22、a rotor-stator like flow that is also of interest [18]. Nu- merical simulations allow the authors to propose a correlation for the Nusselt numbers on the rotating and stationary parts of the seal that are function of the

23、 Reynolds number of the flow, the Prandtl number, the ratio of the fluid and the material thermal conductivity. The influence of geometrical parameters has not been analyzed. The numerical and experimental temperature di

24、stribution and Nusselt number are in reasonable agreement.2. Geometrical and operating configuration2.1. Experimental deviceThe experimental mechanical face seal is presented in Fig. 2. The carbon rotor is fixed on the s

25、haft by means of a support and a cone expander. The stator, made of a fluorspar disc (CaF2), is fixed on an annular piston which ensures three degrees of free- dom with respect to the frame. This enables a dynamic tracki

26、ng of any rotor misalignment. The stator is pressed against the ro- tor by pressurized air acting on the top surface of the annular piston. The thermal properties of the materials of the seal com- ponents are given in Ta

27、ble 1. Hydraulic equipment provides oil at controlled pressure and temperature. The oil is a mineral ISO VG 46. Its characteristics are presented in Table 2. The typical operating conditions and the main dimensions of th

28、e mechani- cal face seal are detailed in Table 3.2.2. Physical backgroundThe oil flow in the mechanical face seal is similar to the flow between a static and a rotating disk with a co-rotating shroud. Owen and Rogers [18

29、] suggested employing the fol- lowing Reynolds number to characterize the flow regime:Re = ρωR2μ (1)Fig. 2. Experimental device.Table 1 Material thermal characteristics and assignmentThermal conductivity k (W/m ?C)Elemen

30、tCarbon 15 RotorStainless steel 46 Shaft, piston, supports, expanderCalcium fluoride 9.7 Stator Elastomer 0.4 sealsTable 2 Fluid propertiesDensity ρ (kg/m3) 850 Specific heat Cp (J/kg ?C) 2000 Thermal conductivity k (W/m

31、 ?C) 0.14 Dynamic viscosity μ (Pa s) 0.055 at 35?CTable 3 Operating conditions and principal dimensionsAngular velocity ω (rpm) 300–1500 Fluid pressure (Pa) 50 000 Inlet fluid temperature (?C) 35 Mass flow rate ˙ m (kg/s

32、) 0.003–0.015 Inner radius of the rotor R (m) 0.0345 Outer radius of the rotor Ro (m) 0.0385 Inner radius of the disk Ri (m) 0.022 Axial clearance H (m) 0.0122 Disk thickness E (m) 0.01There is a superposed flow due to t