Abstract. The contribution is listed possible application of heat pipes in systems for obtaining heat from flue gas of small heat sources. It is also stated in the contribution design an experimental device on which to study the impact of fill (the quantity, type of load) at various temperature parameters (temperature heating and cooling) thermal power transferred to the heat pipe. Is listed measurement methodology using heat pipes designed experimental facility, measurement results and analysis of the results obtained. Heat pipeHeat pipe is formed from vacuum-closed pipe and filled with a suitable working substance at a defined pressure. For purpose of the heat pipe utilization is necessary to consider several factors, which influences its proper function. The choice of the heat pipe is mainly dependent on technical applications, temperature range and compatibility of the substance with pipe material. A crucial factor is how much working substance is used like a filler heat pipe. It is necessary to over a required range of operating parameters to avoid insufficient wetting of the evaporation pipe surface. Insufficient wetting would result in a decreasing performance. Conversely too much working fluid would lead to the formation of large vapor bubbles and the shock phenomena. Figure 1 shows the description of the heat pipe function. Heat pipes are used for heat transfer-heat performance, while the small temperature difference between the evaporation and condensation part is kept. By this technology can be transferred high heat performance, while device dimensions are small. The advantage of heat pipes is particularly intense heat transfer, and finally, simple design, reliability, durability and endurance. Currently, the heat pipes are applied in many branches (communication and computer technology, space technology, etc.).

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This paper describes a mathematical model of heating hot water for indirectly heated hot water heater. Using the established mathematical model was carried out simulation of the device to change its geometrical parameters. Based on the results of simulations was carried out optimization of indirectly heated hot water heater for hot water. Subsequently been made CFD simulations of the device, and those were compared with a mathematical model to verify the accuracy of the proposed mathematical model of heating hot water for indirectly heated hot water heater. Computational methods based on finite volume methods (CFD method) have proved very useful in optimizing indirectly heated hot water heater.

The article describes the measurement methods and data evaluation from a single-stage axial turbine with high reaction (50%). Four operating modes of the turbine were selected, in which the wake traversing behind nozzle and bucket with five-hole pneumatic probes took place. The article further focuses on the evaluation of bucket losses for all four measured operating modes, including the analysis of measurement uncertainties.

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