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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This article proposes a mechanical development of a dry cell in order to obtain HHO through water electrolysis. Calculations and technical specifications of the materials used for implementation are supported by mathematical, physical and chemical formulas and theories (Faraday´s Law, electrolysis process and mechanical design). The importance of mechanical design is focused on achieving efficient use of the energy provided to the cell that allows the H2 and O2 molecules to be separated without overheating the cell, evaporating the water, loss of current due to the geometry of the electrodes (Foucault Current). Moreover, choosing materials for proper implementation and physical robustness is mandatory. In addition, the mechanical design is not justified in different articles. Nevertheless, the mechanical design of the cell and the efficiency in the production of HHO are related. Therefore, the mechanical design and the calculations were performed, as well as the construction of the dry cell to obtain HHO. The results of the implementation and production were placed and compared with what theoretically the dry cell should produce from the law of Faraday. Finally, the volumetric flow of HHO obtained was 2.70 L per minute. It means a production efficiency of 98.68%. It is higher than the majority of the dry cells. / Revisión por pares

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This thesis focuses on identifying acoustic noise generating components in piezoelectric blowers through transverse velocity measurements and the development of a numerical fluid model. Piezoelectric ceramics have proven useful for many industries and areas of research involving: high precision actuators, noise control, ultrasonic devices, and many other areas. As of late, a unique adaptation of piezoelectric ceramics is surfacing in the area of pumping and cooling. Air pumps that use these ceramics replace the traditional electric motor, resulting in lower power consumption, less moving parts, constant pressure gradients, lower overall weight, and a low profile. The current drawback of this application is the acoustic radiation produced by the blowers. Since these blowers are new to market, little research or development has been done to characterize the noise emissions. This thesis studies the acoustic emissions from the front face of a Murata piezoelectric blower. Jet noise and structural vibrations are two acoustic sources of interest that are studied in this research. A Direct Numerical Simulation (DNS) of the fluid flow through a Murata blower is developed to better identify noise generating mechanisms. The model solutions predict trends in sound pressure levels (SPL) of the jet noise and volumetric flow rates. Both the SPL and flow rate are shown to be functions of critical geometrical dimensions within the flow path of a Murata blower. Important dimensional components are identified as well as non-influential ones. Design guidelines are given to reduce noise emission from the front side of a blower and increase the volumetric flow rate. The results of this research have a direct impact on the piezoelectric blower industry and future blower designs.

The diploma thesis deals with the design of the heating and cooling system, inclu-ding hot water preparation for the administrative part of the production hall. The first part of the thesis briefly discusses the history of heating and cooling of office buildings, legislative requirements and current solutions. The second part contains the design of the entire heating and cooling system with heat pump as a source of heat and cold. The final part of the thesis describes the experimental measure-ment and evaluation of the efficiency of the ice rink source.