N2 - In this paper a mathematical model enabling the analysis of the heat-flow phenomena occurring in the waterwalls of the combustion chambers of the boilers for supercritical parameters is proposed. It is a one-dimensional model with distributed parameters based on the solution of equations describing the conservation laws of mass, momentum, and energy. The purpose of the numerical calculations is to determine the distributions of the fluid enthalpy and the temperature of the waterwall pipes. This temperature should not exceed the calculation temperature for particular category of steel. The derived differential equations are solved using two methods: with the use of the implicit difference scheme, in which the mesh with regular nodes was applied, and using the Runge-Kutta method. The temperature distribution of the waterwall pipes is determined using the CFD. All thermophysical properties of the fluid and waterwall pipes are computed in real-time. The time-spatial heat transfer coefficient distribution is also computed in the on-line mode. The heat calculations for the combustion chamber are carried out with the use of the zone method, thus the thermal load distribution of the waterwalls is known. The time needed for the computations is of great importance when taking into consideration calculations carried out in the on-line mode. A correctly solved one-dimensional model ensures the appropriately short computational time.
L1 - http://www.journals.pan.pl/Content/94116/PDF/02_paper.pdf
L2 - http://www.journals.pan.pl/Content/94116
PY - 2010
IS - No 3 September
EP - 36
DO - 10.2478/v10173-010-0012-y
KW - mathematical model
KW - Waterwalls
KW - Supercritical parameters
KW - Distributed parameters
KW - Implicit difference scheme
A1 - Zima, Wiesław
A1 - Grądziel, Sławomir
A1 - Cebula, Artur
PB - The Committee of Thermodynamics and Combustion of the Polish Academy of Sciences and The Institute of Fluid-Flow Machinery Polish Academy of Sciences
DA - 2010
T1 - Modelling of heat and flow phenomena occuring in waterwall tubes of boilers for supercritical steam parameters
SP - 19
UR - http://www.journals.pan.pl/dlibra/publication/edition/94116
T2 - Archives of Thermodynamics