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Archiv článků od 13.4.2015 do 25.1.2016

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25.1.2016
Ing. Václav Peer, Ing. Pavel Friedel

Article is dealing with gasification principles and gasifiers. Gasification is process for gas producing from solid fuels (coal, wastes, biomass). Producer gas can be used in cogeneration unit (piston engine or combustion turbine) for generating of heat and electricity with higher efficiency in comparison with combustion in boiler. All processes in gasifier taking place with regulated supply of gasification media (air, oxygen or steam) and reaction heat.

18.1.2016
Ing. Viacheslav Shemelin, doc. Ing. Tomáš Matuška, Ph.D.

The paper presents an analysis of main design parameters influence (width of the air gap between the absorber and the covering glazing, emissivity of the absorber and insulation thickness) on the thermal performance of solar collector. High-quality flat-plate solar collector was chosen as a reference variant. The aim of the analysis is to show, to what extent it is possible to modify these parameters towards cheaper collectors without significant reduction in energy quality of solar collector in operation.

28.12.2015
Břetislav Koč

Second part of wind power series describes the beginning of wind power in Denmark and in Germany. Both countries began world leaders in wind power development and installation at the turn of the century. In addition the article tells several parallel stories of wind turbines that were significant for the wind branch as development stages or as the dead ends.

14.12.2015
Ing. Roman Vavřička, Ph.D., ČVUT v Praze, Fakulta strojní, Ústav techniky prostředí, Univerzitní Centru energeticky Efektivních Budov ČVUT v Praze

The article discusses the appropriateness of choice source of heat for buildings with low energy requirements in respect of view of the designer and investor. The main theme is the use of renewable energy sources.

14.12.2015
Ing. Vladimír Stupavský, redakce TZB-info, Klastr Česká peleta

Pellet heating systems are a fairly new technology. Consequently there may be problems caused by the lack of experience with this technology. This also applies to pellet storage installations. Pellet stores have to fulfil a number of requirements to make sure that the pellet quality is maintained and safe operation is guaranteed.
The ENplus storage guideline describes the requirements to preserve fuel quality and provide safe storage of pellets for both professionals (such as installers) and consumers. It covers the technical properties of pellet stores as well as information on safe and adequate operation of these stores. They do not replace installation guidelines and instructions from pellet boiler/storage manufacturers but do take precedence over advice from installers/distributors. Planning aids and filling regulations from manufacturers of pellet storage, extraction systems and pellet boilers must be followed.
Professional practices are the cornerstone of successful market development.

7.12.2015
Ing. Michaela Perďochová, Ph.D., VŠB – TU Ostrava, Fakulta bezpečnostního inženýrství

Solid biofuels emit gaseous products in the air during their storage. These gases can be dangerous for health and the environment. The composition and quantity of the gaseous products is dependent on many factors. Temperature belongs among the most important factors. This article deals with the qualitative and quantitative analysis of gaseous products released during heating of forest wood chips. It was assessed usage gaseous products for indication of state of stored materials. Samples of wood chips were heated in a furnace in the temperature range 50–150 °C in increments of 50 °C for one hour. Analysis of the gases was performed by using an infrared spectrometer with Fourier transformation.
These findings can be used for correct selection of safety precaution.

30.11.2015
Ing. Michaela Perďochová, Ph.D., VŠB – TU Ostrava, Fakulta bezpečnostního inženýrství

Usage of solid biofuels increases due to substitution of fossil fuels. This fact contributes to increasing of danger of fire due to spontaneous combustion. Spontaneous combustion of these materials occurs during their storage in large piles. This tendency to spontaneous combustion is not the same, but is influenced by various factors. This article deals with the determination of tend to spontaneous combustion and evaluation of effect of moisture on self – ignition temperature of four kinds of wood chips. Evaluation of tendency to spontaneous combustion was performed according to standard EN 15188, in an isothermal furnace. The results have implications for the specification of safe conditions of storage of coal and wood substances and the selection of safety measures.

30.11.2015
Ing. Jan Vidim

The aim of electricity distributor is that customers may be sourced if a constant amount of energy. When properly appliances division into groups according to how they can be turned off, it is possible to reduce the agreed value of the load shedding and save on fixed fees. The regulator load shedding so in the short term applies.

16.11.2015
Břetislav Koč

The article guides us through wind turbines history from first experiments over new rotor designs and power enlargements to first wind turbines in the Czech republic, in the USA, Denmark and other "pioneer instalations" in Europeans countries.

15.11.2015
Ing. Josef Hylský, Ing. Dávid Strachala, Doc. Ing. Jiří Vaněk, Ph.D.

In the presented article is analyzed aging of the photovoltaic power plant panels located in Dukovany. Photovoltaic power plant in Dukovany (identified also as PV power plant) is the oldest PV power plants built in the Czech Republic. PV power plant was put into service in 1998. After 17 years of working is slowly ending its life. This work compared an electricity production in individual years, decreasing of produce energy from the values given by the manufacturer and also describing visible defects on selected modules.

18.9.2015
Česká peleta, z.s.p.o.

At the turn of 2014/2015 were created by Directive 2009/28 / EC and revised. 406/2000 Coll. – evaluation standards for installers of renewable energy sources. Since July 1, 2015, every person installing subsidized facilities using RES is required to have successfully passing a relevant examination. In the case of biomass boilers is a test of professional competence called Plumber for biomass boilers, code in the National Qualifications Framework is no. 36-149-H.

17.8.2015
Ing. Petr Červený, VOŠ a SPŠ Volyně

The paper deals with complex solution of heating and economy measures regarding ecology of heat sources and preservation of architectural values of the Volyně college-complex. This solution also includes padding warm and exchange of windows in all complexes. New technology in boiled room was installed with application of boiler for fytomass-burning, gas condensation boilers, thermal pump in system air/water and cogeneration unit for supply electric energy.

13.7.2015
Ing. Jan Koloničný, Ph.D., Ing. Lubomír Martiník, Ing. David Kupka, Ph.D.

The article presents a new condensing boiler with an automatic feeding system and a burner designed for combustion of biomass with high water content. The boiler has a modular layout allowing great variability in arrangement and performance. Heat output of the boiler can vary within the range from 10 to 500 kW. A stand-alone condensation heat exchanger which is essential part of the boiler is designed as self-cleaning without fouling of heat transfer surfaces. The exchanger’s contribution to overall heat output is about 10 % when combusting wood chips with moisture exceeding 40 %.

4.7.2015
Ing. Bronislav Bechník, Ph.D.

In May 2015 Centre for Public Opinion Research (CVVM) conducted public opinion poll, whose results published on its website. Surprisingly, the environmental organization Calla that openly opposes the development of nuclear energy, interprets the results more balanced than the Czech News Agency (ČTK), which should be independent. Interpretation of ČTK is more nuclear-optimistic than the results of the poll. It is worth noting the contradiction between the answers to the first and second questions. On one hand most respondents (45 %) prefer conservation of share of nuclear energy (22 % for increase and 22 % for decrease). On other hand most respondents (44 % against 39 %) prefer to build two more nuclear units at Temelin. Building of two new units at Temelin would definitely lead to an increase in the share of nuclear energy.

15.6.2015
Mgr. Vojtěch Kotecký, Fakulta humanitních studií Univerzity Karlovy v Praze

Coppice is a traditional type of forest management with short harvest period. It has all but disappeared from Czech countryside, but there has been renewed interest in coppicing in recent years. Coppice forests may become a substantial source of energy biomass in rural areas. Two approaches are most relevant: (i) Conversion of some current broadleaved high forests into coppice forests. Coppicing shows worse long term financial returns but higher biomass production and faster yield than conventional high forest. It is interesting for private and municipal owners of small forest properties. (ii) Minor changes in law would make government’s afforestation subsidies available for establishment of new coppice forests in farmland. Nevertheless, they will probably remain a minor counterpart to better yielding short rotation coppice.

25.5.2015
doc. Ing. Tomáš Matuška, Ph.D., ČVUT v Praze, Univerzitní centrum energeticky efektivních budov

Third part of serial focuses on solar system components. The fact, that there is a tendency for undersizing the component to reduce the system price, is expectable. But cases, in which the basic safety guidelines are broken, are just a demonstration of incompetency of installation company not only in the field of solar thermal systems but in the heating branch in general.

25.4.2015
Ing. Vladimír Stupavský, redakce TZB-info, Klastr Česká peleta

In recent months, took place in Berlin and Wels important energy conference that addressed the importance of wood pellets and their role in heating. There were introduced detailed descriptions of world markets with pellets and especially detailed analysis of production and consumption of certified ENplus pellets in the world for the past year. In the following description of the main insights from both conferences that show trends in the pellet industry primarily from the perspective of Europe, which is a defining market for domestic development industry of Czech Republic.

20.4.2015
Ing. Vladimír Stupavský, redakce TZB-info, Klastr Česká peleta

Visit and familiarization with the Engineering Test Institute. The process of certification of automatic boilers for solid fuels – for wood pellets. Description of the activities thermal and environmental testing equipment.

13.4.2015
doc. Ing. Tomáš Matuška, Ph.D., ČVUT v Praze, Univerzitní centrum energeticky efektivních budov

Second part of serial focuses on solar collectors. Basic axioms of solar thermal engineering are lost if designer or installation company wants to supply the a solar system at all „costs“. It is not easy to recognize the quality of solar collector at first sight. But i tis simpler and less expensive to make a cross-check of the solar collector than to replace one after another by new ones because of low heat output.


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