Flow and heat transfer characteristics in the porous wick condenser of CPL

Yi, Qu; Peng, Xiaofeng; Liu, Tao

doi:10.1007/bf02916736

Cited by 4 publications

(5 citation statements)

References 4 publications

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“…The black area represents the liquid phase, while the white area represents the vapor phase. In the visualization experiment, the velocity of the inlet is 0.6 m/s and the temperature of the inlet is 337.15 K. The temperature difference between the inlet and cold wall is set to be 10 K. It is ( observed that interfaces of present model and Qu et al [24] show similar shape. Hence, the calculation model provided in this paper can be used with confidence.…”

Section: Crid Independent Test and Model Validationmentioning

confidence: 75%

“…4, the results of the present model agree well with those in [23] and the geo-reconstruct scheme used in this paper effectively avoids fuzzy interface. Qu et al [24] conducted a visual experimental research on the same plat type condenser with porous wick, and the shape of the liquid film at steady state is given in fig. 5.…”

Section: Crid Independent Test and Model Validationmentioning

confidence: 99%

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Condensation heat transfer characteristics of the alkali metal thermal to electric converter (AMTEC) porous wick condenser

Xiao

Deng

et al. 2019

THERM SCI

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An axisymmetric 2-D mathematical model was established and the volume of fluid +method was adopted to numerically investigate the condensation heat transfer process of alkali metal in the alkali metal thermal to electric converter (AMTEC) porous wick condenser. The steady-state physical fields of working medium were obtained and the impacts of some relevant parameters including geometrical and operational parameters on condensation heat transfer characteristics were discussed. The results show that the thickness of the liquid sodium increases along the radial direction. The temperature distribution in liquid phase is approximately linear. The condensation rate at the phasechange interface decreases along the radial direction, and the cold end heat flux, q, increases initially and then decreases along the radial direction. The porous wick condenser has very limited self-adaptive ability once the mass flow rate, M , exceeds in some critical value. In addition, there is a corresponding T for a certain M to ensure the w in stable phase-change interface. The performance of AMTEC can be enhanced by reducing the distance between artery and cell wall.

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Section: Crid Independent Test and Model Validationmentioning

confidence: 75%

Section: Crid Independent Test and Model Validationmentioning

confidence: 99%

Condensation heat transfer characteristics of the alkali metal thermal to electric converter (AMTEC) porous wick condenser

Xiao

Deng

et al. 2019

THERM SCI

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“…To solve or partly solve the above problems, a CPL needs preconditioning to ensure that the wick is wetted before applying power to the evaporator for startup. This involves the reservoir preheating to "prime" the evaporator pump and collapse any vapor bubbles, and this process is tedious and sometimes time consuming [6,7]. Once the priming procedure is completed, the heat can be applied to the capillary evaporator to start the loop operation, and this startup procedure is called "fully flooded startup."…”

Section: Introductionmentioning

confidence: 99%

“…When the pressure difference required to perform this purge exceeds the capillary limit of the wick, vapor bubbles from the vapor side will certainly be injected through the wick into the liquid core and cause depriming, which is responsible for more than 90% of CPL depriming [8]. To enhance the possibility of startup success, the CPL system generally uses starter heaters and a starter pump for clearing liquid in the vapor line; nevertheless, sometimes the CPL still cannot start up successfully [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…The results showed that these structures can reduce, even eliminate the pressure oscillations, and greatly improve the operational performance of the CPL. Qu et al [7] conducted an analytical investigation to understand the internal fluid flow and heat transfer in the condenser with porous wick of a CPL system. A mathematical model is proposed and used to describe the flow and heat transfer, especially interfacial transport phenomena.…”

Section: Introductionmentioning

confidence: 99%

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Experimental Investigation of New Flat-Plate-Type Capillary Pumped Loop

Liu

Jiang

2008

Journal of Thermophysics and Heat Transfer

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A capillary pumped loop is a two-phase heat transfer device which has been increasingly applied in thermal control of satellite or spacecraft and electronic cooling. However, startup performance of a normal capillary pumped loop is poor and hydrodynamic oscillation in the system appears sometime during its operation. A flat-plate-type capillary pumped loop is constructed and tested in the present study, which combines the advantages of a capillary pumped loop and a loop heat pipe by improving both system and components. In the present capillary pumped loop, both evaporator and condenser are designed as a type of flat plate with porous wick, and a reservoir is used to control and adjust operation temperature of the system. In addition, a subcooler is adopted to improve the quality of working fluid flowing back to the evaporator. A plane type of evaporator with a cross channel for the liquid supply was made to reduce the probability of a dry-out point caused by strong evaporation in the case of high heat flux, and therefore to enhance the stability of the system. Also, a plane type of condenser with a porous wick is designed, which is of the three ports for vapor-pipe inlet, liquid-pipe outlet, and an adjusting pipe connected to a reservoir. The startup performance of the system benefits greatly from this three-port design, as liquid in the system can be easily pressed into a reservoir due to resistance reduction. The performance of a capillary pumped loop prototype was tested in startup, persistence operations, and different vacuum. Startup experiments under different heat loads and working conditions were conducted. Excellent startup performance, being stable and easy, has been shown for the plane-type capillary pumped loop system, which validates the new configuration. Pressure oscillation and temperature fluctuation in the system were reduced largely owing to the induction of a porous wick in the plane condenser. During experimental processes lasting more than 10 h, the new type capillary pumped loop shows outstanding thermal behavior and no dry-out phenomena were observed. The testing results indicate that 1) the new capillary pumped loop system shows excellent startup performance without pressure priming and liquid clearing of vapor line; and 2) the new capillary pumped loop system is stable under very severe operational conditions, such as low load, sudden power step, etc.

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