Experimental determination of the heat exchange coefficient of industrial steam pipelines
The article discusses and analyses the factors related to the use of a thermal imaging camera to determine heat loss in industrial steam pipelines at factories from chemical and metallurgical industry, by measuring their surface temperature. The generally accepted enthalpy method for determination of the loss has serious drawback it gives accurate results, but in averaged units in which it is impossible to take account of the contribution of the different parts and components of the pipeline in the total heat loss. The unavailability of information on where, how and in what way along the route this loss is formed does not allow prompt and specific measures to be taken for its reduction. An attempt has been made to structure empirically a reliable analytic dependence for determination of the heat exchange coefficient, bringing together the various factors influencing the heat exchange. By the method of the least squares the free coefficient and the exponent have been determined of criterion equation satisfying initial and boundary conditions of the experiment. Based on the obtained results for determining the heat losses by measuring the surface temperature of steam pipelines with a thermal imaging system, a reliable and acceptable method is proposed, which has a place in engineering practice. For this purpose, an industrial experiment has been carried out at three actually operating steam pipelines of different diameters and steam parameters. A criterion equation has been derived that can be used as a mathematical model for software products with a practical orientation for regular assessment of heat losses of steam pipelines. Values of heat losses determined through energy balance of heat carrier and heat flux from the outer surface of the steam pipelines have been compared. Results for the heat exchange coefficient, obtained through a balance have been compared with the analytically determined values based on current standards. A new method has been developed for express evaluations of the current heat losses of the steam pipeline in real time, as the sum of the losses through its individual components gives as average values 9÷12 % increased results for the losses compared to the enthalpy method. Its great advantage is that it can be used selectively to determine the losses through individual sections of the steam pipeline.
Kruczek, T. (2013). Determination of annual heat losses from heat and steam pipeline networks and economic analysis of their thermomodernisation. Energy, 62, 120–131. doi: http://doi.org/10.1016/j.energy.2013.08.019
Pavlenko, A., Cheilytko, A., Ilin, S., Belokon, Y. (2022). Determination of porous constructions heat transfer coefficient. Procedia Structural Integrity, 36, 3–9. doi: http://doi.org/10.1016/j.prostr.2021.12.075
Acikgoz, O., Batur Çolak, A., Camci, M., Karakoyun, Y., Dalkilic, S. A. (2022). Machine learning approach to predict the heat transfer coefficients pertaining to a radiant cooling system coupled with mixed and forced convection, International Journal of Thermal Sciences, 178, 107624. doi: http://doi.org/10.1016/j.ijthermalsci.2022.107624
Rabiu, A., Na, W.-H., Akpenpuun, T. D., Rasheed, A., Adesanya, M. A., Ogunlowo, Q. O. et. al. (2022). Determination of overall heat transfer coefficient for greenhouse energy-saving screen using Trnsys and hotbox. Biosystems Engineering, 217, 83–101. doi: http://doi.org/10.1016/j.biosystemseng.2022.03.002
Li, J., Xie, X., Li, S., Zhang, Q. (2022). Reliable potential and spatial size of virtual cathode obtained by an emissive probe with accurate filament temperature in a vacuum. Vacuum, 200, 111013. doi: http://doi.org/10.1016/j.vacuum.2022.111013
Modest, M. F., Mazumder, S.; Modest, M. F., Mazumder, S. (Eds.) (2022). Fundamentals of Thermal Radiation. Radiative Heat Transfer Academic Press, 1–29. doi: http://doi.org/10.1016/b978-0-12-818143-0.00009-2
Guan, H., Xiao, T., Luo, W., Gu, J., He, R., Xu, P. (2022). Automatic fault diagnosis algorithm for hot water pipes based on infrared thermal images. Building and Environment, 218, 109111. doi: http://doi.org/10.1016/j.buildenv.2022.109111
Zhou, S., O'Neill, Z., O'Neill, C. (2018). A review of leakage detection methods for district heating networks. Applied Thermal Engineering, 137, 567–574. doi: http://doi.org/10.1016/j.applthermaleng.2018.04.010
Schmid, J., Bicat, D., Elfner, M., Bauer, H.-J. (2021). Improved in-situ calibration applied to infrared thermography under high angles of view. Infrared Physics & Technology, 119, 103952. doi: http://doi.org/10.1016/j.infrared.2021.103952
Reddy, K. S., Veershetty, G., Srihari Vikram, T. (2016). Effect of wind speed and direction on convective heat losses from solar parabolic dish modified cavity receiver. Solar Energy, 131, 183–198. doi: http://doi.org/10.1016/j.solener.2016.02.039
Bruno, R., Ferraro, V., Bevilacqua, P., Arcuri, N. (2022). On the assessment of the heat transfer coefficients on building components: A comparison between modeled and experimental data. Building and Environment, 216, 108995. doi: http://doi.org/10.1016/j.buildenv.2022.108995
Burmeister, L. C. (1993). Convective heat transfer. John Wiley & Sons inc.
Eckert, E. R. G., Drake, Jr. R. M. (1987). Analysis of Heat and Mass Transfer. Washington: Hemisphere Publishing Corp.
Incropera, F. P., Dewitt, D. P., Bergman, T. L., Lavine, A. S. (2007). Fundamentals of heat and mass transfer. John Wiley & Sons, Inc, 1070. Available at: https://hyominsite.files.wordpress.com/2015/03/fundamentals-of-heat-and-mass-transfer-6th-edition.pdf
Turner, W. C., Malloy, J. F. (1981). Thermal Insulation Handbook. New York: McGraw Hill, 50.
ASTM C 680 – 89 Standard Practice for Determination of Heat Gain or Loss and the Surface Temperatures of Insulated Pipe and Equipment Systems by the Use of a Computer Program. Available at: http://nawabi.de/project/hrsg/ASTM-C680.pdf
EN ISO 12241:1998 Thermal insulation for building equipment and industrial installations – Calculation Rules. Available at: https://www.iso.org/standard/21345.html
Huntley, H. (1967). Dimensional analysis. Dover, 158
Kostov, P. S., Nikolov, Ch. I., Atanasov, K. Т., Kalchev, S. V. (2014). Possible to determine of the heat losses in supports by using a thermal cameras. XIX International Conference, I, 186–190. Available at: http://copepm.eu/documents/tom_1.pdf
Chakyrova, D., Andreev, A. (2021). Exergoeconomic analysis and optimization of a waste tires pyrolysis, Journal of Chemical Technology and Metallurgy, 56 (6), 1234–1248. Available at: https://dl.uctm.edu/journal/node/j2021-6/15_20-17p1234-1248.pdf
Doseva, N., Chakyrova, D. (2019). Thermoeconomic analysis of biogas engines powered cogeneration system. Journal of Thermal Engineering, 5 (2), 93–107. doi: http://doi.org/10.18186/thermal.532210
Velichkova, R., Stankov, P., Simova, I., Markov, D., Angelova, R., Pushkarov, M., Denev, I. (2021). Integrated System for Wave Energy Harvesting. Proceedings of the 2021 6th International Symposium on Environment-Friendly Energies and Applications. doi: http://doi.org/10.1109/efea49713.2021.9406234
Penkova, N. Y., Mladenov, B. M., Krumov, K. S. (2019). Finite elements analysis of mass transfer and mechanical processes in ceramic ware at convective drying. IOP Conference Series: Materials Science and Engineering, 595 (1), 012003. doi: http://doi.org/10.1088/1757-899x/595/1/012003
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