Calculation of Solar Heat Gain on Large Insulated Outdoor Vessel
Calculation of Solar Heat Gain on Large Insulated Outdoor Vessel
(OP)
I need to calculate the heat flux into a large, outdoor vessel, which is about 60 feet diameter and 40 feet tall, with a domed roof. I have all the dimensions and insulation details. The insulation is styrofoam with a reflective metal jacket. The vessel is about -20 F inside.
My question is, do I need to consider solar heating at all? If so, how to estimate it? I was thinking of using 100 F as the temperature of the outside of the shell (worst case), which would give me a temperature difference of 120 F. Should I raise the shell temperature a little to account for solar heating?
Thanks in advance.
My question is, do I need to consider solar heating at all? If so, how to estimate it? I was thinking of using 100 F as the temperature of the outside of the shell (worst case), which would give me a temperature difference of 120 F. Should I raise the shell temperature a little to account for solar heating?
Thanks in advance.
Tony Miller
Cornerstone Engineering Group, p.c.
http://www.cegpc.com





RE: Calculation of Solar Heat Gain on Large Insulated Outdoor Vessel
RE: Calculation of Solar Heat Gain on Large Insulated Outdoor Vessel
Tony Miller
Cornerstone Engineering Group, p.c.
http://www.cegpc.com
RE: Calculation of Solar Heat Gain on Large Insulated Outdoor Vessel
Solar heat load is certainly a factor in outdoor tanks. In fact, radiation is generally a factor - both heating and cooling, although the latter is probably not an issue at -20F, unless you are in a very cold place. (Although a clear night sky can have an equivalent temperature below -20F, and so may be a factor.) Also, both radiative transfer in general and solar heating specifically, will be reduced by the shiny metal jacket.
One reference would be ASHRAE handbooks. The Fundamentals volume deals with solar loading. I am less familiar with the other volumes, but they may also address your issues.
I have used FEA methods for this type of work in the past. It allows the calculations to reflect the time dependency of the solar loading.
HTH
Jack
Jack M. Kleinfeld, P.E. Kleinfeld Technical Services, Inc.
Infrared Thermography, Finite Element Analysis, Process Engineering
www.KleinfeldTechnical.com
RE: Calculation of Solar Heat Gain on Large Insulated Outdoor Vessel
Tony Miller
Cornerstone Engineering Group, p.c.
http://www.cegpc.com