An update of the macroeconometric model of the Polish economy NECMOD

The paper presents an update of the structural macroeconometric model of the Polish economy NECMOD. The updated version of the model is, similarly as its predecessor, used at the National Bank of Poland for forecasting and policy simulation exercises. NECMOD is a hybrid, medium-scale and partially forward-looking quarterly model with its structure rooted in the economic theory. Great emphasis has been put on modelling of the supply side of the economy and mechanisms that introduce high persistency of shocks. The present version of NECMOD was estimated on the data covering a period from 1995 to 2008. Its main advantage, as compared to the previous version, is a more detailed and coherent approach to the modelling of the external sector block. Now, secular changes in the exchange rate and foreign trade dynamics are explained jointly with reference to the taste-for-variety theory. Moreover, the current version of the model better reflects interdependencies between domestic and external sector, i.e. via exchange rate - wealth channel.Polish economy, macroeconometric model, macroeconomic model

Equipment of the cold crucible for metal oxides melting

Snahou tohoto článku je představit unikátní vybavení studeného kelímku, jež umožňuje indukční tavení oxidů kovů, tzv. induction skull melting (ISM). Tavení je založeno na principu indukčního ohřevu, kdy je energie od induktoru přenášena do vsázky prostřednictvím takzvaného studeného kelímku. Tento způsob tavby umožňuje dosahovat velmi vysokých teplot taveniny (až 4 000 °C). To je umožněno tím, že na rozhraní mezi studeným kelímkem a taveninou si v průběhu tavby vytváří tavenina vlastní skořepinu (skull). Mezi touto skořepinou a studeným kelímkem přitom zároveň vzniká vzduchová mezera.This article aims to present unique equipment of a cold crucible (CC) that allows induction melting of metal oxides (the so-called induction skull melting – ISM). Melting is based on the principle of induction heating, in which energy is transferred from the inductor to the load using the CC. This method of melting makes it possible to reach very high temperatures of melt (up to 4,000 ° C). This is allowed by the fact that the melt forms its own skull crucible at the interface between the CC and the melt during melting. At the same time, an air gap is created between the skull and the CC

Specialised Frequency Converter For Induction Devices

The article focuses on developing a frequency converter for induction surface hardening, which involves designing a device that can precisely and efficiently control the frequency of the alternating magnetic field used to heat the material. The frequency converter should be capable of operating at different frequencies, depending on the material being heated and the desired depth of penetration. Additionally, the converter should be designed to provide high power density to achieve rapid and uniform heating of the workpiece surface. Control algorithms should also be developed to ensure precise and accurate control of the induction process. Ultimately, a well-designed frequency converter can result in efficient and effective surface hardening while also prolonging the service life of the induction heating equipment

Vývoj kalicího stroje a inteligentního řízení

Tento článek se zaměřuje na představení vyvinutého kalicího stroje založeného na indukčním ohřevu. Tento stroj se od běžných řešení výrazně liší především rozsáhlým měřicím systémem, díky němuž máme dokonalý přehled o tom, co se během procesu děje. Dále je popsán vyvinutý řídicí systém využívající PLC. V článku je zmíněn i návrh vlastního řízení frekvenčního měniče pomocí mikrokontrolérů.This article focuses on introducing the developed hardening machine based on induction heating. This machine differs significantly from conventional solutions mainly due to its extensive measuring system, which gives us a complete overview of what is happening during the process. Furthermore, the developed control system using PLC is described. This paper also mentions the design of own control of the frequency converter using microcontrollers

Manipulation System for Measuring Heat Flux in Radioactive Melt

Abstract This article is focused on introducing of the manipulation system, which is used to insert equipment or measuring probes into the chamber of a cold crucible during experimental induction skull melting. The measuring probe could be, e.g., calorimeter for measuring heat flux from a melt, which is created in the cold crucible by electromagnetic induction. The first part describes the technical parameters of the manipulator and the possibilities of manipulator controlling. The manipulation system is controlled by the algorithm implemented in the programmable logic controller CompactRIO or by mechanical controller called manual pulse generator, which is independent of the programmable logic controller. Different control methods increase the safety of the system. The next part contents basic information about the control algorithm based on LabVIEW software and the user interface of the touch screen. The article also deals with testing the manipulator, which was used in an experiment simulating corium behavior under conditions of the severe accident of a nuclear power plant. The last part describes simulations of electromagnetic field and temperature field in the chamber of the cold crucible, which were confirmed with real measuring. The goal of the simulations was to determine the effect on the manipulation system and calculation of Joule's losses in the calorimeter before immersion into the melt. The most significant heat transfer to the calorimeter was the radiation from a melt, which was also calculated.</jats:p

Possibilities of Using an Energy Surplus of Photovoltaic Power Plants

Nowadays, the installation of photovoltaic power plants on the roof of houses is becoming more and more common. Compared to earlier times, the surplus electricity to the grid is not well-financed. It leads to increasing pressure to maximize the use of the electricity generated on the premises. Energy storage in batteries is becoming standard but is still insufficient. In most cases, the distribution of the building's consumption does not correspond to the PV generation, and the size of the battery storage would be economically prohibitive to utilize the surplus fully. A solution to this problem can be to control selected appliances depending on the PV production. This paper describes controlling the output of heat pumps, EV chargers, and resistive load. Our goal is to develop a control system for smaller buildings that allows communication between the devices and control their operation depending on the current and future PV production