Re: [TRNSYS-users] Quick question on solar collector model

[David BRADLEY <d.bradley@tess-inc.com>]

Dev,
  The thermal losses from a collector are computed based on a temperature difference between the fluid and the ambient. There are a number of different standards, however. Some base these losses on the difference between the inlet fluid temperature and the ambient while others use a mean fluid temperature. In order to get a more accurate estimate of the losses, Type536 breaks up the fluid flowing through the collector into a series of nodes, each of which is assumed to be isothermal and each of whose energy balance is represented by a differential equation. The higher the number of nodes the more accurate the temperature profile of liquid flowing through the collector. As you increase the number of nodes the outlet temperature should change less and less.
Kind regards,
 David

On 3/6/2014 08:05, dev sharma wrote:

Hey All,

 

Can someone please tell me the physical significance of No. of Nodes in modelling a solar thermal collector? or how is T_out dependent on it?

 

My observation by running the model is that T_out increases with increase in number of nodes, but the effect is such that T_out is dependent on the exponential of this number somehow. Am I even close to making sense?

 

Thanks

Dev Sharma

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