Pipe heat loss
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This post was last edited by Desert Fish on 2015-10-8 at 20:08. Pipe 273, with a length of 3 meters; the medium is methanol at a temperature of 180 degrees, while the ambient temperature is around 25 degrees. The pipe has not been insulated, and it’s unknown how large the heat loss is. How should the heat loss be calculated?
There is a book titled \"Calculation Methods\", which states that the heat dissipation rate is approximately 6–7 kW
It is also necessary to know the mass flow rate and specific heat of the medium inside the pipeline
The heat dissipation capacity is roughly 6–7 kW. Could you explain what this means? In terms of kilojoules, how much is that approximately?
The heat dissipation capacity is roughly 6–7 kW. Could you explain what this means? In terms of kilojoules, how much is that approximately?
This post was last edited by bfdlwolf on 2015-12-31 at 11:47. The heat dissipation calculation for bare tubes involves combined radiation-convection heat transfer; one can refer to the calculations related to \"combined radiation-convection heat transfer\" in the first volume of \"Principles of Chemical Engineering\". The key to such calculations lies in determining the combined heat transfer coefficient, which is the sum of the radiation heat transfer coefficient and the convection heat transfer coefficient. The radiation heat transfer coefficient depends on factors such as the radiation coefficient, the surface temperature, and the ambient temperature; relevant formulas can be found for this purpose. The difficulty lies in calculating the convection heat transfer coefficient, for which there are relevant formulas in the principles of chemical engineering (for both natural convection and forced convection situations), and these calculations are quite complex. The combined heating coefficient due to radiation and convection can also be determined by referring to the formulas for calculating the surface heat transfer coefficient in the \"Design and Calculation Volume 1 of the Manual for the Installation Design of Process Piping in Petrochemical Plants.\" It should be noted that these formulas apply to the heat transfer coefficient of the outer surface of insulated structures, and it represents the sum of the radiation heat transfer coefficient and the convection heating coefficient. The convection heat transfer coefficient takes into account conditions such as wind outside, no wind inside, and enclosed environments. In my opinion, the heat transfer coefficient of the outer surface of bare pipes can be determined using the formulas provided in this manual.