The Performance of Joule Thomson Refrigerator

Hong, Yong-Ju; Park, Seong-Je; Kim, Hyo-Bong; Choi, Yun Seok

doi:10.1007/0-387-27533-9_63

Cited by 8 publications

(4 citation statements)

References 4 publications

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“…Considering the above factors, it is found that the suitable high-pressure gases available on the market are argon and nitrogen. By referring to the literature, it can be seen that argon or nitrogen is also used in the open refrigeration system mostly, [28][29][30][31][32] and the ranges of pressure and refrigeration temperature are consistent with this study. Therefore, nitrogen and argon are used as refrigerants in this study.…”

Section: Experimental Apparatus and Experimental Proceduressupporting

confidence: 85%

Characterization of a distributed Joule‐Thomson effect cooler with pillars

et al. 2021

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The application of general Joule-Thomson (J-T) coolers in the integrated electronic equipment is limited by its compactness in the heat exchanger and cooling power (a few milliwatts to hundreds of milliwatts). However, the microchannel with pillars has many advantages, such as compact structure, tiny axial thermal conductivity, and large heat transfer area. Besides, when the pressure variation of the fluid is large in the microchannel, the distributed Joule-Thomson effect is generated significantly. Therefore, this study proposed a throttling and heat exchange structure, where heat transfer and throttling coexisted, and fabricated a laminated microchannel distributed J-T cooler with pillars utilizing the processing technology of printed circuit heat exchanger.The refrigeration performance concerning the cold-end temperature, cooling power, and temperature distribution was then investigated through experiments with two refrigerants (argon and nitrogen). The study implies that the temperature difference and cooling power of the cooler both increase with the rise of the inlet pressure with argon, the no-load cold-end temperature is 166.1 K, and the gross cooling power is 3.83 W at 5.20 MPa. The temperature of the cooler increases with the rise of heat load, while the parasitic heat load decreases. The cold-end temperature is 186.0 K, then the parasitic heat load and the gross cooling power are respectively 3.17 W and 7.17 W at 5.20 MPa under the heat load's condition of 4 W. Comparing the refrigeration performance of nitrogen and argon, the cold-end temperature of nitrogen at 5.20 MPa is 235.7 K, which is close to that of argon at 2.98 MPa. Whereas the cooling time of nitrogen is slightly shorter than that of argon, and the cooling power is 3.10 W, higher than that of argon. In addition, this study provides new insight into increasing the cooling power and reducing the application cost of miniature coolers.

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Section: Experimental Apparatus and Experimental Proceduressupporting

confidence: 85%

Characterization of a distributed Joule‐Thomson effect cooler with pillars

et al. 2021

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“…Next, we study the warp products [35][36][37][38] of the Kerr black hole on the equatorial plane on θ = π/2. To do this, we rewrite the metric (1.1) as follows For a comoving observer on the equatorial plane, we find…”

Section: Geometrical Aspects Of Kerr Spacetimementioning

confidence: 99%

Global embeddings and hydrodynamic properties of Kerr black hole

Hong

2016

Mod. Phys. Lett. A

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In the presence of a rotating Kerr black hole, we investigate hydrodynamics of the massive particles and massless photons, to construct relations among number density, pressure and internal energy density of the massive particles and photons around the rotating Kerr black hole and to study an accretion onto the black hole. On equatorial plane of the Kerr black hole, we investigate the bound orbits of the massive particles and photons around the black hole to produce their radial, azimuthal and precession frequencies. With these frequencies we study the black holes GRO~J1655-40 and 4U~1543-47, to explicitly obtain the radial, azimuthal and precession frequencies of the massive particles in the flow of perfect fluid. We next consider the massive particles in the stable circular orbit of radius of $1.0~ly$ around the supernovas SN 1979C, SN 1987A and SN 2213-1745 in the Kerr curved spacetime, and around the potential supermassive Schwarzschild black holes M87, NGC 3115, NGC 4594, NGC 3377, NGC 4258, M31, M32 and Galatic center, to estimate their radial and azimuthal frequencies, which are shown to be the same results as those in no precession motion. The photon unstable orbit is also discussed in terms of the impact parameter of the photon trajectory. Finally, on the equatorial plane of the Kerr black hole, we construct the global flat embedding structures possessing (9+3) dimensionalities outside and inside the event horizon of the rotating Kerr black hole. Moreover, on the plane we investigate the warp products of the Kerr spacetime.Comment: 10 page

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“…Now, in order to investigate physical properties inside the black hole event horizon, we consider a multiply warped product manifold whose metric is of the form [23][24][25][26]…”

Section: Type-i Extended Btz Spacetimementioning

confidence: 99%

“…The interior Schwarzschild spacetime has been represented as a multiply warped spacetime with warping functions [23] to produce the Ricci curvature in terms of f 1 and f 2 for the multiply warped products of the form M = R × f1 R × f2 S 2 . The interior RN-AdS spacetime has been also investigated by using the multiply warped product scheme [25]. In the (2+1) dimensional spacetime, the multiply warped product has been studied to investigate the interior solutions of the (2+1) BTZ black holes and the exterior solutions of the (2+1) de Sitter black holes [26].…”

Section: Introductionmentioning

confidence: 99%