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Sections of the superconducting magnets of the SIS100 particle accelerator, under construction at the Facility for Antiproton and Ion Research (FAIR), the Society for Heavy Ion Research (GSI), Darmstadt, are going to be connected with the by-pass lines. Each line will be used to transfer a two-phase helium flow and an electric current. The electric current will be carried by four pairs of superconducting Nuclotron-type cables. Fast-ramping currents are expected to cause the generation of heat within the cables. In this work the results of a numerical thermal analysis of a bus-bar are presented. The amount of heat transferred from the environment was found based on geometric dimensions of the line and applied insulation. The amount of hysteresis loss, generated in the cable during the operation under most demanding regime of the operation of the accelerator, was calculated. According to the amount of the generated heat, the amount of the hysteresis loss is low in relation to the heat generated in the superconducting magnets. Also it was found that the cable used in the line still retains a large margin of current-carrying capacity.

Superconducting magnets in the SIS100 particle accelerator require the supply of liquid helium and electric current. Both are transported with by-pass lines designed at Wrocław University of Technology. Bus-bars used to transfer an electric current between the sections of the accelerator will be encased in a steel shell. Eddy currents are expected to appear in the shell during fast-ramp operation of magnets. Heat generation, which should be limited in any cryogenic system, will appear in the shell. In this work the amount of heat generated is assessed depending on the geometry of an assembly of the bus-bars and the shell. Numerical and analytical calculations are described. It was found that heat generation in the shell is relatively small when compared to other sources present in the accelerator and its value strongly depends on the geometry of the shell. The distribution of eddy currents and generated heat for different geometrical options are presented. Based on the results of the calculations the optimal design is proposed.

Electromagnetic properties of the superconductors predestine them to serve as materials for the efficient and light magnetic shields. Very high attenuation factors are possible to be obtained. Superconducting elements of different geometry can be used. However, shielding effect is limited by the critical current of a superconductor. This work describes the model of an arbitrarily shaped thin superconducting plates made of BSCCO, with the focus on circular and rectangular samples. The plates are subjected to transverse magnetic fields of different strength and shape. Changes of critical current density are considered. The distribution of the shielded magnetic field and shielding current is presented. Results show that the magnetic field attenuation occurs and depend on the shape and material of a plate. It was also observed that coarse meshes can be used to obtain reliable results concerning magnetic field distribution, thus saving computational time.

Regasification is the process of evaporating and compressing LNG (liquid natural gas) so that the product meets the parameters of a local distribution network. During this process large amounts of potentially useful exergy are destroyed. There were several proposals of using this potential in practice. In this paper the methods for electric energy production using cold exergy from a LNG stream are investigated. The new improvement is proposed for an absorption power cycle by coupling it with an organic Rankine cycle. The new components for working fluid are evaluated. The proposed solution is compared to existing ones and analyzed using a computer model. A significant increase of exergetic efficiency and power output is observed when compared to previous solutions.

The application of renewable energy sources poses the problems connected with output volatility. In order to decrease this effect the energy storage technologies can be applied, particularly fuel cells connected with hydrogen storage. In this paper the application of SOFC system for a household in Poland is proposed. Economic and technical analysis is performed. It was found that the proposed installation is profitable after 25 years of operation when compared with conventional solution - heat pumps and gas-fired boilers

Utilization of the cold exergy of regasified liquid natural gas (LNG) improves the overall efficiency of the product chain by regaining the part of energy used to liquefy natural gas (NG). The application of a standard organic Rankine cycle in the case of high-pressure LNG (complying with the requirements of the gas delivery networks after regasification) leads to a comparatively low power generation and a large loss of exergy. In this paper we proposed a novel multi-stage power-generating cycle using a binary working fluid. By the separation of the ethane-krypton mixture into several streams with different component ratios and mass flows it was possible to adjust the process parameters and increase the net power that can be produced per unit of destroyed exergy. Furthermore, the proper selection of parameters allowed heat capacity to be increased at any temperature region in the heat exchanger, and thus increase exergy efficiency. Factors affecting the thermodynamic behavior of the system were presented and analyzed with numerical simulations. A significant increase of total exergetic efficiency (from 10% to 19.3%) was observed when compared with previously reported results for similar operating conditions. A net power of more than 15.4 kWh/t of regasified NG at network pressure (8.5 MPa) was obtained.

The model of a single Nuclotron-type cable is presented. The goal of this model is to assess the behaviour of the cable under different loads. Two meshes with different simplifications are applied. In the first case, the superconductor in the cable is modelled as single region. Second mesh considers individual strands of the cable. The significant differences between the distributions of the electric current density obtained with both models are observed. The magnetic field remains roughly similar.

Recent advances in the measurements with sensitive magnetic field sensors made the issue of magnetic shielding important. The application of high temperature superconductors allows to obtain full shielding in zero field cooling conditions for DC and low frequency magnetic fields by the means of the Meissner effect. However, currently used conventional bulk magnetic shields maintain full shielding only in low magnetic fields—up to approximately 10 mT. In this paper, it is proposed to apply an additional screen made of a coated superconducting tape in order to increase the magnetic field interval of full shielding region. Computer model of such set of screens was created in Matlab and validated experimentally. Improvement of shielding quality was observed experimentally and calculated with the model.

Tilted stacks of HTS tapes show favourable properties in terms of magnetisation. Magnetised stacks can be applied in superconducting rotating machines. In such case they will be subjected to varying magnetic fields and heat generation will occur. Therefore it is important to understand heat transfer in anisotropic structure of a stack to avoid overheating and optimise the shape for maximum magnetisation. To analyse the heat transfer a computational procedure to find components of anisotropic thermal conductivity is developed and compared with existing experimental data. The material parameters ready to use in other analyses are provided. Anisotropy of the structure of the HTS tapes plays crucial role in definition of the thermal behaviour of the investigated elements. The thermal behaviour of the stacks with different angles of tilt is investigated with a numerical model. Results show that the geometry of the stack significantly affects heat transfer. Analytical formulas describing the thermal behaviour of the stack depending on its dimensions are developed. The method to increase the speed of calculations by homogenising the stack is presented and its accuracy assessed.