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PhD Thesis - Energy Systems Research Unit - University of Strathclyde

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heating is not required. An example <strong>of</strong> the heating system definition window<br />

for a space heating storage heater can be seen in Appendix 1, Figure A1.48.<br />

To calculate the performance <strong>of</strong> a storage heater, the initial and maximum<br />

storage levels must be given, and then, for each timestep, the algorithms<br />

outlined in Figure 5.23 and 5.24 must be followed.<br />

C:\My Documents\Nic\<strong>Thesis</strong>\Old\Figures\Chapter5 Figures\stor heat 1.abc<br />

storage = storage - storage = storage level (kWh)<br />

09 October 2001<br />

((loss x storage)<br />

loss = percentage loss per hour<br />

Add Heat to<br />

/ (100 x timesteps)) max = maximum storage level (kWh)<br />

13:46<br />

used = electricity used (kW)<br />

Storage Heater<br />

elec = electricity supply available (kW)<br />

timesteps = number <strong>of</strong> timesteps per hour<br />

Yes<br />

used = required<br />

storage = m ax<br />

flag = 1<br />

is elec > 0 ?<br />

is storage =<br />

max ?<br />

required = ((m ax - storage) x 100 x tim esteps) / efficiency<br />

rated = rated power x number <strong>of</strong> heaters x 100 / efficiency<br />

is required <<br />

rated ?<br />

Yes<br />

storage = 0<br />

is required <<br />

Yes No<br />

elec ?<br />

No<br />

is storage < 0 ?<br />

No<br />

is heat storage<br />

allowed at any time<br />

?<br />

Yes<br />

No<br />

used = rated<br />

storage = (rated x efficiency) /<br />

(100 x timesteps)<br />

166<br />

Yes<br />

is it between the start and<br />

end tim e for heat storage ?<br />

No<br />

flag = 1<br />

is elec < rated ?<br />

Yes<br />

used = elec<br />

storage = (elec x efficiency)<br />

/ (100 x timesteps)<br />

Figure 5.23 Algorithm for Adding Heat to a Storage Heater<br />

Yes<br />

Yes<br />

No<br />

No<br />

no electricity used<br />

no change in storage<br />

No<br />

used = rated<br />

storage = (rated x efficiency)<br />

/ (100 x timesteps)

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