Mutual Thermal Resistances between Pipe Layers
Mutual Thermal Resistances between Pipe Layers
(OP)
Ref: Palsson, Halldor | Analysis of Numerical Methods for Simulating Temperature Dynamics in District Heating Pipes - please check pg. 62 at LINK (CLICK!)
INTRO: In this reference, the mutual thermal resistances between layers as water-insulation, ground-surrounding, and insulation-ground are defined for a buried pre-insulated pipe, figure and formulations given below.
QUESTION: I want to improve the model given in this reference by studying the layers as water, steel, insulation, and ground so I need to obtain the mutual thermal resistances between water-steel, steel-insulation, insulation-ground, and ground-surrounding. I couldn't find a reference describing how to find the thermal resistances between layers of a cylinder (e.g. thermal resistance between pipe wall and insulation and others). Can any of you help me either by giving formulations or by guiding me to a reference?
FIGURE:

FORMULATIONS:

DETAILS:

“In life, the truest guide is science” – Mustafa Kemal Atatürk
INTRO: In this reference, the mutual thermal resistances between layers as water-insulation, ground-surrounding, and insulation-ground are defined for a buried pre-insulated pipe, figure and formulations given below.
QUESTION: I want to improve the model given in this reference by studying the layers as water, steel, insulation, and ground so I need to obtain the mutual thermal resistances between water-steel, steel-insulation, insulation-ground, and ground-surrounding. I couldn't find a reference describing how to find the thermal resistances between layers of a cylinder (e.g. thermal resistance between pipe wall and insulation and others). Can any of you help me either by giving formulations or by guiding me to a reference?
FIGURE:

FORMULATIONS:

DETAILS:

“In life, the truest guide is science” – Mustafa Kemal Atatürk
RE: Mutual Thermal Resistances between Pipe Layers
TTFN (ta ta for now)
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RE: Mutual Thermal Resistances between Pipe Layers
“In life, the truest guide is science” – Mustafa Kemal Atatürk
RE: Mutual Thermal Resistances between Pipe Layers
Heat conduction from water to steel is subject to a transfer coefficient depending on water flow rates etc.
By "thermal inertia" do you mean a transient heat up analysis?
Can be done but needs a transient analysis program.
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RE: Mutual Thermal Resistances between Pipe Layers
> they are usually in intimate contact, so the interface layer is extremely thin
> the area of non-contact is usually small
In general, thermal inertia is dominated by the thermal mass of the object and the bulk thermal resistance.
Furthermore, the particular example you selected, water and pipe, are dominated by convection on the water side, and the bulk conductance of water comes indirectly into the calculation.
TTFN (ta ta for now)
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RE: Mutual Thermal Resistances between Pipe Layers
The main purpose is with the solution of transient water temperature profile through a pipe segment considering the thermal inertia by the insulation and ground. I simply solve the system of partial differential equations for all sections (water, insulation, and ground) simultaneously. As this reference indicates, there need to be thermal resistances defined between these sections of the buried insulated pipe.
“In life, the truest guide is science” – Mustafa Kemal Atatürk
RE: Mutual Thermal Resistances between Pipe Layers
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm