Technical College - Al-Musayyib,  Al-Furat Al-Awsat Technical University discussed a Ph.D. thesis on the thermal-hydraulic properties of a four-pipe concentric heat exchanger in Al-Musayyib thermal power plant by the postgraduate student, Mrs. Rana Ali Hussein. The thesis aimed at achieving a new design for the heat exchanger to solve the problem in Al-Musayyib thermal power plant. The thesis confirmed that the four-pipe concentric heat exchanger gives a good improvement in heat transfer, compared to the shell and tube heat exchanger, as it was observed that the hot water temperature decreased by (5.75 percent) in STHE, while the temperature of the hot water decreased by (15 percent) in FCPHE. The thesis recommended studying the effect of using different fluids on the efficiency of the heat exchanger, the effect of Nano-fluids on its efficiency, and the use of corrugated tubes for a heat exchanger of four united tubes.