Add to ORKGCogeneration (also combined heat and power, CHP) uses a heat produced together with electricity for coverage of heat demand. Cogeneration units of low power are recently used for purpose of heating individual buildings and coverage of heat demand of small-scale industrial enterprises. The theoretical part of this Bachelor thesis is focused on explanation of principle of cogeneration production and there are basic advantages and important indicators of cogeneration production. There is brief summary of cogeneration devices according to type of drive unit. The fourth chapter is devoted to short description of heat exchanger. The fifth chapter includes description of elemental thermal processes and possibility of heat transfer. There is a desc...