Experimental validation of a heat transfer model in underground power cable systems

This paper presents the laboratory test stand that is used for experimental validation of underground power cable system models. Determination of temperature distribution in the vicinity of the cable is the main goal of the study. The paper considers a system of three power cables, situated in the in-line arrangement, and buried in sand. Three electrical heaters of special construction are used in order to simulate the heat flux that is generated in the power cables during their operation. The test stand is designed to be placed in a thermoclimatic chamber, which allows testing the system in various thermal conditions when the ambient temperature changes by 20 C to 30 C. Numerical computations of the steady-state temperature fields are performed using the finite element method

Simulations of Safety Vales for Fluid Power Systems

Hydraulic power systems are widely used in heavy machinery. Safety of such a systems have a major importance due to the fact that any failure may cause environmental contamination or serious injury. One of the component which protects hydraulic drive systems against excessive rising of working pressure is a safety valve which aim is to maintain pressure in the systems below acceptable level. Pressure control valves which plays important role in a hydraulic systems may have very simple or complex structure. Even in case of the simplest structure of such valve modeling is not an easy task. The new quality in designing hydraulic valves bring CFD method and FSI (Fluid Structure Interaction) methods

Institutional Aspects of Health and Safety at Work in Poland

Health and safety at work have their legal basis in international and Polish law - source of law currently valid in Poland. For efficiently functioning system of health and safety at work it is necessary to build appropriate institutional environment. The purpose of the article is to analyse the institutional system of health and safety at work in Poland based on source of law currently valid in Poland and forming remarks de lege lata and de lege ferenda in this scope