- #1
davidgrant23
- 22
- 0
Hi all,
I am currently considering a heat transfer problem. In this problem a rectangular vessel made of stainless steel is heated by a surrounding jacket with hot combustion flue gases flowing through it. This means that the heating of the rectangular vessel is achieved primarily through conductive heat transfer through the outer wall of the vessel. The vessel is filled with reactants with the hope of raising the temperature inside the vessel to a minimum temp required for reaction to proceed. What I am trying to calculate is whether the energy required for the reaction to proceed can be provided by the hot gases circulating the vessel, and what the temperature inside the vessel would be?
Now, the energy content of the hot flue gases is 12 MJ/kg, while the enthalpy for reaction of the reactants is 1 MJ/kg. The flowrate of the flue gases is 1.86 kg/hr, which corresponds to 0.006 MW. The flowrate of the reactants is 3 kg/hr, which means that the 0.0009 MW is required for the reaction to proceed. This suggested that there is sufficient energy for the reaction to proceed.
What I am unsure to do however is to estimate the heat loss by conduction through the vessel wall, as I do not know what the temperature inside the vessel is. How do I estimate/calculate the temperature inside the vessel in order to calculate the heat loss? I can assume that the temperature of the hot gases is 1473 K, the heat transfer area is 0.3 m^2, the length is 1.5 m, the thickness is 0.003 m, and the thermal conductivity is 25 W/mK.
Cheers,
Dave
I am currently considering a heat transfer problem. In this problem a rectangular vessel made of stainless steel is heated by a surrounding jacket with hot combustion flue gases flowing through it. This means that the heating of the rectangular vessel is achieved primarily through conductive heat transfer through the outer wall of the vessel. The vessel is filled with reactants with the hope of raising the temperature inside the vessel to a minimum temp required for reaction to proceed. What I am trying to calculate is whether the energy required for the reaction to proceed can be provided by the hot gases circulating the vessel, and what the temperature inside the vessel would be?
Now, the energy content of the hot flue gases is 12 MJ/kg, while the enthalpy for reaction of the reactants is 1 MJ/kg. The flowrate of the flue gases is 1.86 kg/hr, which corresponds to 0.006 MW. The flowrate of the reactants is 3 kg/hr, which means that the 0.0009 MW is required for the reaction to proceed. This suggested that there is sufficient energy for the reaction to proceed.
What I am unsure to do however is to estimate the heat loss by conduction through the vessel wall, as I do not know what the temperature inside the vessel is. How do I estimate/calculate the temperature inside the vessel in order to calculate the heat loss? I can assume that the temperature of the hot gases is 1473 K, the heat transfer area is 0.3 m^2, the length is 1.5 m, the thickness is 0.003 m, and the thermal conductivity is 25 W/mK.
Cheers,
Dave