The objective of the study was to analyse the theoretical model of development, ‘smart slow city’, based on two concepts of development of modern cities, i.e. ‘smart city’ and ‘slow city’. Conclusions mainly rely on the performed reference literature studies, which allowed for a synthetic presentation of the characteristics of the two discussed models of development, which are the basis for characterizing the hybrid model of the ‘smart slow city’. The comparison of city development models was made on the basis of the following characteristics: the genesis of the city development idea, the rate of changes and the model of life related to it, key city development factors, the main objective of changes, key actors, activity areas, specialization, scale of urban centres, city image, level of development policy, significance of cooperation etc.
Organic Rankine cycle (ORC) is used, amongst the others, in geothermal facilities, in waste heat recovery or in domestic combined heat and power (CHP) generation. The paper presents optimization of an idealized ORC equivalent of the Carnot cycle with non-zero temperature difference in heat exchangers and with energy dissipation caused by the viscous fluid flow. In this analysis the amount of heat outgoing from the ORC is given. Such a case corresponds to the application of an ORC in domestic CHP. This assumption is different from the most of ORC models where the incoming amount of heat is given.