The topic of this graduate thesis is the analysis of Thermal Power Plant Rijeka with electrical energy generation capacity of 320 MW. The analysis of heat exchanger grid has been done by pinch method. The aim of this thesis is to make thermodynamic analysis of heat flows in the system of the thermal power plant and to find out if the energy usage in the process is rational. As an introduction to the thesis a classical Clausius-Rankine process is shown and described in addition to technical description of the Thermal Power Plant Rijeka's system with a particular attention to regenerative heat exchangers. Considering that one of the most important interests is the system optimization, in short, the reduction of investment and operative expenses in the process industry, the rest of this thesis is based on the synthesizing of the heat exchangers grid using pinch point process. Using pinch point process could result in significant energy savings and reduction of unnecessary energy losses. The heat loss reduction or the reduction of heat emission into the environment also touches on environmental protection as the regulations are increasingly more restrict. Following the theoretical explanation of the method based on a simple example of two hot and two cold flows, the analysis of the concerned Thermal Power Plant Rijeka has been done. In an addition to the thesis, a thermal layout of the Thermal Power Plant Rijeka is created on which the analysis has been based. The concluding part of the thesis brings the results through construction and comparison of composite curves of hot and cold flows showing that the minimal temperatures difference ΔTmin (pinch) is 10,5 °C. According to this result it could be concluded that the energy usage in this system is rational. Further analysis shows that the minimal temperatures difference ΔTmin could be reduced which would result in more energy savings; however that would cause an increase of the investment expenses which again poses the question whether this system would be optimal. On the other hand, this would be a system optimization which exceeds this thesis work frame.