Page 155 - Materials Chemistry, Second Edition

References 151
A full ranking sequence of all DH systems can also be obtained according to the simulation
results. However, this may lead to some kind of misunderstanding and thus is not encour-
aged. DMs may believe that the alternative with largest utilities dominates all the others,
disregarding the fact that ranking sequence is subject to uncertainties in weighting. Therefore,
SMAA method is used to help understand the evaluation by using the rank acceptability in-
dices and the confidence factors. SMAA plus FWS can make clear that what kind of weight
information will favor what kind of alternative taking into account of the probability. This
makes the combination of SMAA and FWS more reliable in the multicriteria evaluation.
Therefore, the proposed method can also be used in other MCDM problems.

7.4 Conclusions

In this study, the stochastic multicriteria analysis (SMAA) method in combination with the
feasible weight space (FWS) are used to evaluate the DH systems considering uncertainties in
criteria performance values (PVs) and weighting. The uncertainties in criteria PVs are treated
using uniform distribution function within the uncertainty range of each criterion, and un-
certainties in weighting are addressed directly by the Monte Carlo simulation in SMAA.
The statistic variables of rank acceptability indices, confidence factors, central weight vectors,
and cross confidence factors of SMAA can help DMs understand what kind of weight infor-
mation will favor what kind of best alternatives to what extent and of better discriminations.
The method was demonstrated in a city in the north of China, and the results indicate that
at present, the coal-fired CHP has the best chance to be the most preferred DH technology in
this area with DH load at 10MW level or higher, especially the economic criterion is empha-
sized. Otherwise the gas-fired HOB can be more suitable for DH, because it dominates all
three heat pump (HP) technologies. Among the HP systems, the water source heat pump
(WSHP) is better than ground source heat pump (GSHP) and solar energy heat pump in
the case study area. SMAA also helps reveal the inefficient alternatives of oil- and coal-fired
HOBs, because they are dominated by other DH technologies even considering the uncer-
tainties. A full ranking of the alternatives is not recommended in this study, because it will
very easily lead to a misunderstanding that the best alternative dominates all the others in any
situation. On the contrary, we should bear in mind that the any ranking is subject to uncer-
tainties, which should be well considered.

Acknowledgments
This study is funded by Academy of Finland funding (grant number NO. 299186). We would also like to thank the
“Xinghai” talent project of Dalian University of Technology.

References
Cao, Y., Chen, G.M., Xu, W.F., 2002. Optimization of heating modes for medium and large cities. J. HVAC 32 (1), 7–10.
David, H.A., Nagaraja, H.N., 2003. Order Statistics. Wiley Series in Probability and Statistics.
Durbach, I.N., Stewart, T.J., 2012. Modeling uncertainty in multi-criteria decision analysis. Eur. J. Oper. Res. 223, 1–14.