heat capacity
heat capacity
(OP)
a fluid with a higher heat capacity is a good coolant, but what about heating up a fluid. would a higher heat capacity fluid make a good heating medium?
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RE: heat capacity
m777182
RE: heat capacity
From just a heat-transfer point of view when the (single phase) fluid is heating, and flows turbulently through the tubes of a given heat exchanger, the convection coefficient, h, is proportional to
κ = thermal conductivity
η = viscosity
c = specific heat capacity or simply specific heat
G = mass velocity
When the density, ρ, the annualized costs of a unit of heat exchanging surface Ks, and a unit of pumping power Kp, are included, the value of h is approximately proportional to
Thus, when selecting fluids for heating purposes one can use a similar formula for comparison.
There are, of course, other factors to contemplate such as:
• low cost,
• compatibility with materials of construction,
• low vapor pressure,
• thermal stability,
• ability to tolerate contaminants,
• fire safety,
• low toxicity,
• low reactivity in case of leakage,
• easy reclamation or disposal
Thus, it appears that specific heat capacity is just one of the factors to look for in heat-transfer fluids and not necessarily the most important one.