feasibility studies on the use of mixed · pdf file · 2017-07-30the advancement in...

http://www.iaeme.com/IJMET/index.asp 1357 [email protected]

International Journal of Mechanical Engineering and Technology (IJMET)

Volume 8, Issue 7, July 2017, pp. 1357–1361, Article ID: IJMET_08_07_146

Available online at http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=8&IType=7

ISSN Print: 0976-6340 and ISSN Online: 0976-6359

© IAEME Publication Scopus Indexed

FEASIBILITY STUDIES ON THE USE OF MIXED

CRYOGENS IN HTS CABLES

Priyanka Anand, Gaurav Vyas, Raja Sekhar Dondapati and Praveen Kumar Seepana

School of Mechanical Engineering,

Lovely Professional University, Phagwara, Punjab, India.

ABSTRACT

The advancement in field of cryogenics is vividly seen in recent days. From space

to medical field, also in gas industry and in mechanical separation, cryogenics has

marked its impact. Superconductivity is its one major application which requires

cryogens as working fluid. Cryogens are liquefied gases stored under low

temperature. In the present work, mixture of two cryogens namely liquid nitrogen and

liquid oxygen is considered. The studies on thermophysical properties such as density,

viscosity, thermal conductivity are carried out under the operating temperature of 70-

100K and pressure range of 0.9-1.3MPa by using SUPERTRAPP®. The analysis

provides increase in specific heat and decrease in density, viscosity and thermal

conductivity with increase in temperature.

Key words: Liquid nitrogen, liquid oxygen, thermophysical properties and HTS

cables.

Cite this Article: Priyanka Anand, Gaurav Vyas, Raja Sekhar Dondapati and Praveen

Kumar Seepana Feasibility Studies on The Use of Mixed Cryogens in HTS Cables.

International Journal of Mechanical Engineering and Technology, 8(7), 2017, pp.

1357–1361.

http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=8&IType=7

1. INTRODUCTION The conventional power transmission systems, in near future, are to be replaced by HTS (high

temperature superconducting) cables for better and efficient performance. However these

HTS cables exhibit various technological challenges in cooling. For cooling, liquefied gases

commonly known as Cryogens are used. Many studies have been carried out however mostly

for liquid nitrogen. A comparison of liquid nitrogen and liquid helium for electron

cryotomography [1], use of subcooled liquid nitrogen refrigerators (circulation system) for

HTS power system [2], also the application of cryogens as thermal energy carrier and liquid

energy storage unit [3],[4]. With the advancement of technologies in cryogenics, mixed

cryogens cooling system was used for HTS power application where solid-liquid nitrogen

cryogen is used [5].HTS cables works on the concept of superconductivity having vast

application in electric power sector [6].



In the present research work, mixture of two cryogens, liquid nitrogen (LN2) and liquid

oxygen (LOX) is considered under the operating temperature of 70-100K and pressure range

of 0.9-1.3MPa. The mixture composition is considered to be 10gms and the thermophysical

properties of mixed cryogen are evaluated. Dondapati [7] evaluated the thermophysical

properties of supercritical nitrogen (SCN). From the obtained results pressure drop and heat

transfer analysis can be done for HTS cables [8]. Afrianto [9] conducted a numerical study on

liquid natural gas (LNG) and evaluated the properties of LNG using NIST database standard 4

(SUPERTRAPP) version 3.2

2. RESEARCH METHODOLOGY

In the following research work, mixed cryogen, liquid nitrogen (LN2) and liquid oxygen

(LOX), is selected for feasibility studies on use of these mixed cryogens in HTS cables. The

thermophysical properties of mixed cryogen are evaluated using NIST database standard 4

(SUPERTRAPP®) versions 3.2.1. Different composition of 10-90%, 20-80%, 30-70%, 40-

60%, 50-50%, 60-40%, 70-30%, 80-20%, 90-10% are considered for mixed cryogen.

Different values of density, viscosity, thermal conductivity and specific heat are obtained at

the operating temperature and pressure range.

3. RESULTS AND DISCUSSION Following results represents the thermophysical properties such as specific heat, density,

viscosity and thermal conductivity as function of temperature with the operating pressure and

temperature range of 0.9-1.3 MPa and 70-100K for mixed cryogens. From all the obtained

results it can be concluded that specific heat increases with increase in temperature whereas

density, viscosity and thermal conductivity decreases with increase in temperature at varying

composition of liquid nitrogen and liquid oxygen .

Figure 1Specific heat, Density, Viscosity and Thermal Conductivity as function of temperature at

0.9MPa

Feasibility Studies on The Use of Mixed Cryogens in HTS Cables


Figure 2 Specific heat, Density, Viscosity and Thermal Conductivity as function of temperature at

1.0MPa


1.1MPa


1.2MPa




1.3MPa

4. CONCLUSION The present research work investigates the thermophysical properties of liquid nitrogen and

liquid oxygen at the operating temperature of 70-100K and pressure of 0.9-1.3 MPa with the

use of National Institute of Standard and Technology (NIST) Supertrapp®. Results obtained

for specific heat, density, viscosity and thermal conductivity shows that with increase in

temperature specific heat increases. Moreover density, viscosity and thermal conductivity

decreases at varying pressure and mixture composition.

5. ACKNOWLEDGEMENT With the help of (NIST) SUPERTRAPP®, the feasibility studies on use of mixed cryogen are

done by evaluating thermophysical properties. Thus, a kind gratitude is extended towards the

National Institute of Standard and Technology.

REFERENCES

[1] C. V. Iancu, E. R. Wright, J. B. Heymann, and G. J. Jensen, “A comparison of liquid

nitrogen and liquid helium as cryogens for electron cryotomography,” J. Struct. Biol., vol.

153, no. 3, pp. 231–240, 2006.

[2] Suzuki, Y., Yoshida, S., &Kamioka, Y. (2003). Subcooled liquid nitrogen refrigerator for

HTS power systems. Cryogenics, 43(10–11), 597–602.

[3] Li, Y., Chen, H., & Ding, Y. (2010). Fundamentals and applications of cryogen as a

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[5] Song, J. Bin, & Lee, H. (2012). Mixed cryogen cooling systems for HTS power

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[6] Masur, L. J., Buczek, D., Harley, E., Kodenkandath, T., Li, X., Lynch, J.Kellers, J. (2003).

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[7] Dondapati, R. S., Ravula, J., Thadela, S., & Usurumarti, P. R. (2015). Analytical

approximations for thermophysical properties of supercritical nitrogen (SCN) to be used

Feasibility Studies on The Use of Mixed Cryogens in HTS Cables


in futuristic high temperature superconducting (HTS) cables. Physica C:

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[8] Dondapati, R. S., & Rao, V. V. (2013). Pressure Drop and Heat Transfer Analysis of Long

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[9] Handry Afrianto, Md. Riyad Tanshen, B. Munkhbayar,U. Tony Suryo, Hanshik Chung and

Hyomin Jeong (2014),” A numerical investigation on LNG flow and heat transfer

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