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1

PyroSim / Polyurethane combustion heat to simulate a car fire.

« on: February 18, 2023, 06:26:12 pm »

Good evening,

I am simulating a car fire in a parking lot.

Considering the following parameters.

HRR = 4,800 Kw,

For the "Reaction" section, I have considered that polyurethane is being burned.

&REAC ID='POLYURETHANE', FYI='NFPA Babrauskas', FUEL='REAC_FUEL', C=6.3, H=7.1, O=2.1, N=1.0, SOOT_YIELD=0.1, RADIATIVE_FRACTION=0.35/

According to what I have studied, the heat of combustion can be calculated with the spreadsheet Combustion Calculator = https://files.thunderheadeng.com/support/files/Combustion_Calculator_v5-0.zip.

Then by copying the values of the products and by-products of the chemical equation into the spreadsheet Combustion Calculator,
I get a heat of combustion of 19,024 Kj/Kg which can be seen in the attached images.

But the problem is that I understand that the heat of combustion for a burning car must be between 24,000 to 26,000 Kj/Kg.
Does this mean that the polyurethane burner I chose in Pyrosim does not meet the heat of combustion I need?

Can someone provide me the correct chemical equation to produce the amount of heat of combustion as indicated in the standards (between 24 to 26Mj/Kg ?? ).

I hope your comments can help me.

Best regards.

Carlos P.

2

PyroSim / Re: what's wrong with this centrifugal jet fan

« on: March 09, 2020, 09:15:31 am »

Hola Teiter,

soy nuevo en pyrosim, me puedes dar una mano, en tu modelo que compartiste, en el objeto de impulsión, fui a la seccion de louver, donde esta x, y y z,
y le puse a Y=-1 y Z=-1 , para que la orientación sea inclinada hacia el piso, pero cuando ejecuto la animación, el flujo se sigue viendo directo y choca contra la pared.

me puedes indicar como se hace eso del louver. (ademas en tu ejemplo el flujo no va al techo, en mi caso el flujo sale por la boca de descarga pero en forma recta, lineal y choca con la pared)
pero como bien sabes, los jetfan, descargan con algo de inclinación hacia el piso, por eso puso esos valores en louver y no consegui el resultado esperado.

espero tu ayuda , gracias.