New international marine regulations concerning sea transport indicate that one of the ways to meet them is the use of renewable energy sources (RES) on ships. The PV installation mounted on ships is one of solutions. Cooling of PV modules is a way to improve their capacity. The paper presents results of calculation on capacity of PV modules mounted on ships where seawater is used as cooling agent. The calculations were carried out for conditions prevailing in the harbour Świnoujście/Poland. The aim of this paper is to compare PV module's power gain in six characteristic months (January to June) of the statistic year. Analysis of the results obtained for Świnoujście shows that application of seawater in cooling systems of PV modules on ships is justified only for spring and summer seasons.

The consumption of heat energy as well as electric power in an exploitation process of a building construction depends among others on properties of materials applied to construct its partitions. Increasingly, glass is being replaced by plastics in transparent partitions, including multi-wall polycarbonate sheets. Light transmission and solar radiation transferred to the object’s inside through transparent partitions are decisive factors for its lighting and energy balance. The present paper presents an analysis, on an experimental basis, of the changes of total solar transmittance (TST) for a clear twin-wall polycarbonate sheet with a rectangular structure applied as a swimming pool enclosure. Research shows that values of the above parameter do not depend meaningfully on cloudiness but on time of day. Values of TST can change in the daytime depending on incidence angles and on shares of direct and diffusive solar radiation in global solar radiation. TST values are in the range 0.6–0.7, and they are lower than the value of 0.8, which is given by the producer in the product card.

Purpose: EC-135P2+ helicopters operated by Polish Medical Air Rescue are highly exposed to environmental particles entering engines when performing helicopter emergency medical services. This paper aims to assess the effectiveness of inlet barrier filters installed to protect the engines, including their impact on maintenance. Design/methodology/approach: The organisation adopted a comprehensive set of measures to predict and limit the impact of dust ingestion including visual inspections, health management and engine trend monitoring based on ground power checks’ (GPC) results. Three alternative particle separation solutions were considered. Finally, helicopter inlets were modified to allow the selected filter system to be installed, which reduced the number of particles ingested by the engine and prevented from premature overhauls. Findings: The analyses carried out enabled not only the selection of the optimal filtration solution and its seamless implementation into the fleet but also confirmed its efficiency. After installing the filters, engines’ lifetime is extended from 500 to 4,500 flight hours while operating costs and the number of maintenance tasks was reduced significantly. Originality/value: Lessons learned from operational experience show that a well-matched particle separation system can mitigate accelerated engine deterioration even if the platform is continuously exposed to environmental particles. The remaining useful life of engines can be predicted using performance models and data from GPC.

The paper presents the experimental stand, methodology, and results of research of the spreading process of water droplets. Droplets with equal volumes were dropped from various heights onto the surface with an initial temperature in the range from 20°C to 110°C. Influence of the initial surface temperature on the critical Weber number is investigated. The critical Weber number characterized the conditions in which the droplets break up. The map of water structure on the heated surface was plotted.