Continual development of internal combustion engines requires greater performance from liquid coolants and heat exchangers to maintain optimal temperature. For the purpose of experimental testing of traditional, compact, and microchannel heat exchangers, a test facility has been designed, constructed, and utilized. The facility includes equipment and instrumentation necessary to create operating conditions and record data primarily for testing plate-fin brazed aluminum heat exchanger where heat is being transferred from liquid to air. Other arrangements of heat exchangers could be tested as well with some modifications. Initial tests were performed at several specified operating conditions for three liquids: water, a traditional glycol based Extended Life Coolant (ELC), and a new Glycol Free Coolant (GFC) in an attempt to characterize their heat transfer ability. Results of the tests found that the product of overall heat transfer coefficient and heat exchanger area (UA) was very similar for GFC and water, and it was less for ELC by a narrow margin of 1.3% difference on average. Uncertainty due to instrumentation accuracy was calculated to be 1.8% on average making the results overall UA unverifiable. Measured pressure drop across the heat exchanger which is proportional to required pumping power was found to be 13.5% higher for GFC than ELC at nominal conditions. The GFC offers similar heat transfer performance and marginally increased pumping power requirements compared to the traditional ELC. Due to similar heat transfer performance and the small effect of pressure drop, GFC would be good alternative to ELC due to its less toxic composition.

This master’s thesis deals with problematics of natural gas microturbine integration into industrial laundry operation. This integration means utilization of waste heat for direct drying and water heating in a heat exchanger. This heated water can be used in further laundry processes, for example laundering. All the experiments were carried out on the cogeneration system that is installed in Laboratory of Energy Intensive Processes in NETME Centre at the Faculty of Mechanical Engineering of Brno University of Technology. This system consists of a natural gas microturbine Capstone C30 with nominal electric power of 30 kW, an industrial dryer Primus DX55 with a nominal capacity of 55 kg for laundry and a heat exchanger Vakading type Vakavlas with nominal power of 53 kW. All necessary theoretical and technical preparation was done in order to carry out experiments as follows: • Standard drying program • Water accumulation test • Test of performance of heat exchanger • Direct drying with the use of microturbine’s flue gases These experiments were analyzed and discussed within this thesis. The main contribution of this work is as follows: • Summary of all the knowledge in the area of direct drying • Creation of methodology of utilization of flue gases for direct drying not only in laundry industry but in related fields • Summary of requirements and ways of heat exchanger testing and determination of heat exchanger parameters • Determination of optimal working settings of installed cogeneration system • Description of weak spots in the system and suggested improvements • Basic economic analysis of operating costs During the experiments, it was found that in case of direct drying better results could be achieved in comparison with standard drying. The functionality of the whole system together with the heat exchanger was verified and thus also the possibility of integrating the turbine into the washing process was confirmed. The integration of a natural gas microturbine is both technically and economically feasible for many industrial applications.