Determination of transient fluid temperature using the inverse method

• Autorzy: Jaremkiewicz M.

Identyfikatory

DOI

10.2478/aoter-2014-0004

• Języki publikacji: EN

Abstrakty

EN

This paper proposes an inverse method to obtain accurate measurements of the transient temperature of fluid. A method for unit step and linear rise of temperature is presented. For this purpose, the thermometer housing is modelled as a full cylindrical element (with no inner hole), divided into four control volumes. Using the control volume method, the heat balance equations can be written for each of the nodes for each of the control volumes. Thus, for a known temperature in the middle of the cylindrical element, the distribution of temperature in three nodes and heat flux at the outer surface were obtained. For a known value of the heat transfer coefficient the temperature of the fluid can be calculated using the boundary condition. Additionally, results of experimental research are presented. The research was carried out during the start-up of an experimental installation, which comprises: a steam generator unit, an installation for boiler feed water treatment, a tray-type deaerator, a blow down flashvessel for heat recovery, a steam pressure reduction station, a boiler control system and a steam header made of martensitic high alloy P91 steel. Based on temperature measurements made in the steam header using the inverse method, accurate measurements of the transient temperature of the steam were obtained. The results of the calculations are compared with the real temperature of the steam, which can be determined for a known pressure and enthalpy.

Słowa kluczowe

EN

temperature measurement; transient conditions; uncertainty analysis

PL

pomiar temperatury; warunki przejściowe; analiza niepewności

• Wydawca: Wydawnictwo Instytutu Maszyn Przepływowych PAN ; Komitet Termodynamiki i Spalania PAN
• Czasopismo: Archives of Thermodynamics
• Rocznik: 2014
• Tom: Vol. 35, no. 1
• Strony: 61--76
• Opis fizyczny: Bibliogr. 10 poz., il.

Twórcy

autor

Jaremkiewicz M.

• Cracow University of Technology, Department of Power Engineering, Jana Pawła II 37, 31-864 Kraków, Poland

Bibliografia

• [1] Michalski L., Eckersdorf K.: Temperature measurements. WNT, Warsaw 1986 (in Polish).
• [2] Jaremkiewicz M., Taler D., Sobota T.: Measuring transient temperature of the medium in power engineering machines and installations. Appl. Therm. Eng. 29(2009), 3374–3379.
• [3] Jaremkiewicz M.: Reduction of dynamic error in measurements of transient fluid temperature. Arch. Thermodyn. 32(2011), 4, 55–66.
• [4] Taler J.: A new space marching method for solving inverse heat conduction problems. Forsch. Ingenieurwes. 64(1999), 296–306.
• [5] Taler J., Duda P.: Solving Direct and Inverse Heat Conduction Problems. Springer, Berlin 2006.
• [6] Carslaw H.S., Jaeger J.C.: Conduction of Heat in Solids. Oxford University Press, Oxford 2008.
• [7] Taler J.: Theory and Practice of Identification of Heat Transfer Processes. Ossolineum, Wrocław 1995 (in Polish).
• [8] Sobota T.: Stand for testing computer systems for continuous monitoring of operation of power boilers, In: Contemporary Energy Technologies and Devices (J. Taler, Ed.), Sekcja Poligrafii PK, Cracow 2007 (in Polish).
• [9] Kreith F.: The CRC Handbook of Mechanical Engineering. CRC Press, Inc., Boca Raton, Florida 1998.
• [10] IMSL Fortran Numerical Library version 7.0. Rogue Wave Software, Inc., October 2010.

Uwagi

EN

The results presented in this paper were obtained from research work co-financed by the National Centre of Research and Development in the framework of the contract PBS1/A4/4/2012 – Applied Research Program – Development of advanced methods to assess the residual life of pressure elements in power plants.