Jozef Jnadacka

• University of Žilina

Safety in hydrogen storage is a key factor for its potential use in modern energy systems. Hydrogen is often referred to as the fuel of the future and therefore poses significant safety challenges due to its high flammability, low molecular density, and ability to easily penetrate various materials. Traditional methods of storing hydrogen include h...

Particulate matter capture is a necessary concern for safeguarding human health and quality of life. This article focuses on enhancing particulate matter capture efficiency via electrostatic precipitation. It deals with expanding the fundamental principle of the single electrode in chimney tubular precipitator to a configuration with multi-tubular...

Phytomass, a renewable energy source, faces the challenge of ash agglomeration due to its low ash fusion temperature. To address this, chemical modification (adding additives) and co-combustion with other fuels are explored. This study focuses on combustion of phytomass with wood biomass and mechanical modifications to the combustion chamber. The g...

Air quality is one of the fundamental parameters in the prospect of a healthy and thriving city environment. With the upcoming tightening of regulations for pollutions in general, it is necessary to provide and access real-time data regarding to the air quality and presence of pollutants within the smart city. The article aims on improving the desi...

Deteriorated air quality is often related to the use of alternative fuels in heat sources, often in the form of waste. This article deals with the chemical composition of four types of alternative fuels: solid non-separable waste, solid non-separable waste with more plastic content, linden leaves and maize husks. The measurements were realized on a...

Various users of small heat sources in household use incorrect solid fuels. This leads to a higher burden on the environment, mainly due to higher production of emissions, but also to various problems during the operation of the heat source. These various complications may arise as a result that these fuels usually have low bulk density, high ash c...

Environmental pollution and air quality are increasingly important topics within the areas of Smart City and state regulations. The aim of the article is to present the progress in the design of the emission monitoring system intended for use in non-industry heating appliances in households. The article analyses potential opportunities in aims of i...

This experimental study aimed to validate the integration of a gravitational loop heat pipe (GLHP) with respect to a gas fireplace insert. The GLHP was utilized to enhance the efficiency of the fireplace by preheating the combustion air with waste heat from flue gases. The experiment involved monitoring key parameters such as vapor and condensate t...

The aim of the article is to present progress in the design of the wireless emission monitoring system intended for use in nonindustry heating appliances in households. Two experimental prototypes were constructed. The first prototype successfully transmitted air quality data via the SIM900 technology, measuring VOC, CO, and CO2 concentrations simu...

The burning of low-quality fuels causes several problems in the operation of combustion equipment, which can negatively affect the equipment’s efficiency. The possibilities for the burning of pellets made from low-quality raw materials are limited mainly by the fusibility of the ash, which settles and melts on the surfaces of the burner, gradually...

At present, small heat sources achieve relatively high efficiency, however, small heat sources have heat loss, of which the most significant is the chimney loss. In the form of flue gases, a large part of the heat is dissipated through the chimney into the air. By removing part of the otherwise unused heat from the flue gas, we get the opportunity...

At present, more and more attention is being paid to the issue of reducing emissions. A separate chapter is represented by emissions of particulate matter, the production of which is reduced so far especially in the areas of industrial production, energy, transport. The area that lags significantly behind the above is the area of heating with small...

The key issue of modern cities is their energy independence, which is still insufficient for most cities in the world. Outages in the supply of energy raw materials can endanger the basic functioning of cities, especially with regard to the heat supply of cities in the colder parts of our earth. This threat is exacerbated as far as the energy sourc...

The aim of our research was to further broaden current knowledge of possible energy storage in an off-grid photovoltaic system. Photovoltaic off-grid systems usually require energy storage for their proper function. The storage of electrical energy serves as a bridge for short-term power outages or to draw energy outside the usual times of solar en...

The article deals with the design of the diameter and the simulation of the distribution of the intensity of the electric field of the charging electrode of the electrostatic precipitator, given the supplied DC voltage. The purpose was to calculate the value of the critical intensity of the electric field, which must be exceeded when trying to achi...

The article analyzes the thermal management of a metal hydride storage tank for hydrogen in the mode of filling the storage tank with hydrogen when it is necessary to cool the metal hydride filling intensively. Cooling is carried out by boiling water at low pressure and therefore also at low temperatures of around 50 °C. In the article, a heat tran...

Many research is aimed at improving municipal solid waste disposal and producing usable energy. Pyrolysis technology not only decreases the volume of municipal solid waste, but it also produces pyrolysis oil, pyrolysis gas, and carbon, all of which have a high calorific value and are widely used in industrial activities. This article focuses on the...

Energy demand reaches high values with its negative impact on the environment, it presents a considerable danger. For environmental and economic reasons, the main strategic tasks in this area are associated with reducing and minimizing energy consumption. The possible solution is preceded in the development phase by the application of optimization...

Air quality and air pollution are important issues, and thus it is necessary to look at possibilities for how to decrease emissions in the atmosphere affordably and effectively. This article focuses on solid aerosols, specifically particulate matter, and the design of a low-cost solution for their decrease in the atmosphere. The mass concentration...

Several factors affect how particulate matter and gaseous emissions are formed during the combustion processes of biomass. The amount of combustion air, as well as its redistribution, is one of these factors. This article deals with the performance and emission parameters determined using different distributions of the amount of combustion air of t...

INTRODUCTION: The study presents a conceptual and detailed design methodology overview of a wireless sensor network (WSN) aimed to evaluate the SmartCity air quality in real-time. The aim of the article is to provide low-cost, reliable, and accurate emission data at remote locations, assisting the 2050 Climate-Neutral target set by the European Com...

A lot of residual biomass has energy value and can be used for further applications through suitable treatments, such as pelletization. This treatment can improve properties, mainly energy density, but can also lead to problems due to their low ash melting temperatures, high ash content, and the formation of harmful compounds during combustion. Thi...

Combustion of biomass-based solid fuels is becoming increasingly popular, especially in small heat sources. A major problem in the combustion of biomass is the increased production of emissions and especially the solid component of PM particles. Currently, the most used solution to this problem is the application of electrostatic chimney separators...

This paper deals with the experimental research and verification of a passive cooling system operating on the principle of a loop gravity heat pipe designed for cooling electrical cabinets. This type of cooling works automatically by changing the state of the working substance and thus saves energy consumption. Since the designed cooling system ens...

The study presents a conceptual design of a wireless sensor network aimed to evaluating the SmartCity air quality in real-time. The sensor devices shall autonomously monitor flue gas temperatures, carbon monoxide (CO) and particulate matter concentrations (PM2.5\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsf...

INTRODUCTION: Production of emissions from small heat sources burning solid fuels in households in Slovakia is relatively high. At the present time, the operation of such devices are neither controlled nor regulated properly and effectively.OBJECTIVES: This work presents a research analysis of current monitoring and maintenance procedures and certi...

Alternative biomass makes up a considerable portion of the waste from biomass processing in forestry and agriculture. The aim of this work was to create pellets from several sources of alternative biomass, e.g., lawn clippings, corn husks, linden leaves, and pine needles, which were compared to pure wood pellets. Analysis of the fuel properties foc...

The article is focused on the use of waste heat by means of a heat pipe in devices producing waste heat, which can be further utilized. Waste heat transfer is ensured through the heat pipe. The evaporator removes excess heat and is transported through a steam pipe to the condenser, where it is further used as needed.

The fundamental problem of the modern society is the waste of resources and our ever-increasing need for energy. A new trend in the EU’s green policy in decreasing carbon footprint and ensuring the energy self-sufficiency of the member states is leading us to look for alternative types of fuels. Stocks of fossil fuels are dwindling and there is no...

The combustion of biomass is accompanied by the formation of particulate matter, the presence of which in the atmosphere harms human health. It is important to show the issues of reducing these pollutants and their impact on human health. This article focuses on the process of biomass combustion. The used model consists of two parts: the combustion...

Woody and agricultural wastes are important fuels in many countries, and have the potential of being even more important in the future. The main problems of plant biomass combustion are low ash melting temperatures and increased emissions. The most widely used treatment to solve the problem of low ash melting point is blending a fuel with an additi...

Currently, there is an increasing trend in the use of biomass for energy purposes, due to global pressure on the use of renewable energy sources and a gradual decline in fossil fuel stocks. However, biomass combustion can be considered as a significant source of particulate concentrations in the atmosphere. Measurement of particles from biomass com...

Accumulation of primary energy of natural gas is a perspective option to store natural gas as artificially created hydrate, where this matter can be stored and, if necessary, can be released to cover energy peaks. Gas can be stored this way at partially higher temperatures and low pressures compared to other storage technologies. The technique of r...

Even though this discovery dates back to 1816, the greatest advancement in technology and understanding of Stirling-cycle devices has occurred in the last 50 years. Although their mass production is currently limited to special-purpose machines, its prospective use is in combination with renewable sources and indicates a potential for commercial pu...

The design of an intelligent building management system is a fundamental problem in designing new modern buildings. The energy management structure is a set of main input devices and relationships between them. The paper presents the issue of thermal comfort conditions with regard to intelligent buildings. Thermal comfort describes the human satisf...

Solid fuels combustion is rather complicated because there is always environment pollution by emissions, mainly by particulate matter. The efforts of heat sources manufacturers and also operators should be increase the effectivity of the combustion process with minimizing of emissions production. Nowadays it is possible effectively burn the biomass...

Achieving efficient combustion of solid fuels, especially biomass, with a low negative impact on the environment is rather complicated. Incorrect settings of combustion conditions can cause various problems like increased production of emissions and ineffective using of energy content of burned fuel. Combustion process may be influenced by many fac...

Nowadays, high emphasis is placed on the efficient use of resources for optimum management of transport infrastructure. The use of non-destructive diagnostics is the main application for visualization and support of intelligent infrastructure models. Moreover, such models also have enormous potential to support the “smart city” concept. Disaster ma...

The correct course of the combustion process has a great influence on several output parameters. In addition to the impact on the performance and efficiency of the device, the impact on the formation and properties of gaseous emissions and solid residue is particularly noticeable. The solid combustion residue, in particular in the form of ash, rema...

Rising use of renewable energy sources has brought many new challenges and use of many unusual energy resources. These resources are often of lower quality, a by-product or simple waste. Landfill gas is one of resources with lower quality and unwanted elements, as sulphur derivatives. After chemical or another treatment, the gas can be used in any...

The article is focused on increasing the efficiency of fireplace inserts by means of a device used to preheat the combustion air with a part of the heat from the flue gases. The proposed device is a heat pipe with a closed loop, where its evaporator takes heat from the flue gas in front of the chimney orifice and transfers it via saturated steam to...

One of the most important issues in choosing a heating system is the question: What kind of fuel can be burned in given heating system. Modern automatic solid fuel boilers are often specialized only on a narrow range of suitable pellet materials. Pellets from cheaper sources are also beginning to appear on the market. However, many burners are unab...

At the present, the numerical techniques, such as computational fluid dynamic (CFD) is useful engineering tool for design and optimization process. The CFD gives a possibility to predict the combustion phenomena. This article deals with biomass combustion simulation by using the Eddy Dissipation Concept (EDC) model. The Eddy Dissipation Concept (ED...

The main topic of my article is the search for new energy raw materials especially low cost biodegradable municipal waste (BMW). Local governments in European union spend a lot of money on collection and transportation BMW which ends in the landfills. However, this material carry a significant amount of energy stored in chemical bonds. This energy...

At the present is still paid a lot of attention to particulate matter, because these particles have negative effect to environment and also they are harmful to human health. It is a reason why we must reduce their concentration in the atmosphere. They are getting into atmosphere from various mobile, as well as stationary sources including combustio...

The biomass combustion process affects several aspects, fuel properties, amount and distribution of combustion air and others. One of these aspects is the geometric shape, respectively fuel batch shape. This work deals with the influence of the geometric shape of the fuel in a small local heat source. As an experimental heat source was used a firep...

It is important to pay attention particulate matter mainly due to their negative effects on human health. Into the atmosphere, they are getting from various mobile, as well as stationary sources including combustion. These emissions consist of solid and liquid material dispersed in the atmosphere. It is important to separate particulate matter befo...

Wood pellets as biofuel are more and more used in small heat sources in Europe. Standard wood pellets are produced from wood sawdust without bark. The paper deals about the impact of bark in wood pellets on their properties and combustion process. Special attention in this work is paid to production of particulate matter during combustion of wood p...

Exhaust gases from combustion plants contain complex mixtures of air pollutants, of which many are harmful to human health. From all of these pollutants, particulate matter has the greatest negative effect on health. Small heat sources with biomass combustion are associated with high concentrations of particulate matter. It is crucial to reduce the...

The aim of this paper is to point out possible solutions to the further development of heat pipes by numerical modelling of phase-change heat transfer. Numerical modelling has now become a standard method that helps to reduce the economic costs of research and development of new and innovative devices. The article describes the procedures for using...

Air quality is related to the using of solid fuel based heat sources in which the human factor has a major influence on the quality of combustion, which can lead to higher emissions into the air. One of the negative factors is the use of alternative fuels in heat sources. The article deals with the combustion of various alternative fuels, on a wast...

Process of production wood pellets is difficult and this process has an impact on the final properties of pellets. The article deals with the comparison of the energy and mechanical properties of experimental pellets that have been made under different conditions. Sample A was manufactured in laboratory conditions and sample B was made in factory p...

The article deals with the utilizing of solar energy by the means of concentric trough collector based on own design. It focuses on achieving optimal position of the trough with respect to incident radiation during its operation. Due to the collector virtual sun tracking system, which was proved to be ineffective and could not achieve the desired r...

It is very important to separate particulate matter before their leaving into the air because of their harmful impact on human health. It exists a lot of devices, which can separate these particles. But their implementation and operation in small heat source can be considerably difficult on finances, and often have complex maintenance. Therefore, i...

The effect of beech wood burnt in a furnace of fireplace insert on the energy efficiency, energy performance and emission production is analysed in the paper. Burning the fire beech firewood with the moisture content of W = 12.49% resulted in the highest energy performance, the highest energy efficiency and the lowest emission production at the sam...

The combustion leads to pollution with particulate matters (PM). These emissions are considered to cause the greatest harm to human health. Particulate pollutants consist of the following substances: carbon, ammonium, metals, organic materials, nitrates and sulfates. This article deals with analysis of the particulate matters samples from wood biom...

One of the important fuel properties is ash melting. Fuel with high ash sintering is not applicable for most of the boilers. Sintering is the process that can occur in the burner and block air flow to the base fuel layer. One of the materials, which can participate on this process, is wood bark. The ash melting from combustion of wood bark has nega...

This work deals with the utilization of solar energy using parabolic trough collector. Testing of solar collector manufactured according our own design has taken place in Žilina. Collector consists of firm frame attached to concrete floor, which limits the sun tracking to one axis. Trough of the collector is oriented as east-west position with a sm...

Most popular renewable energy source is biomass. The typical form of biomass is wood. Use of wood for fuel have long tradition in Slovakia. Between a normally trees in Slovakia belongs beech and spruce. This article deals with the energy properties of spruce (Picea Abies). On different parts of the tree have been performed experimental measurements...

The pulp and paper industry in Europe produces over 11 million tons of waste per year. Given high landfill operational costs, thermal co-processing with biomass may be a viable management and valorisation option for such wastes. In this work, the analysis of biomass (wood sawdust), mixture of primary and secondary pulp mill sludge and their respect...

Particulate matter arises also during combustion of solid fuels and then pollutes our atmosphere. Therefore, these particles are one of the most watched emissions. Several factors influence on their formation. It is possible to reduction of particulate matter formation with knowing and affecting these factors. Knowing of PM take-off velocity is imp...

Rural areas are characterized by a larger number of older family houses with higher fuel consumption for heating. Some areas are not gasified, which means that the fuel base for heating the buildings is very limited. Heating is mainly covered by solid fuels with high emissions and low efficiency. But at the same time, the amount of energy in the fo...

The combustion of biomass is relatively complicated. To minimize the emission production it is necessary to ensure the optimal setting of combustion process. The article deals with the impact of bark content in wood biomass on performance and emission parameters of a small heat source. The increasing content of bark in wood biomass changes its chem...

Constant effort to reduce heating costs leads not only to production of high-quality pellets from pure wood but also to production of cheaper vegetable pellets of inferior quality in terms of energy properties (1, 2). The combustion of alternative pellets in small boilers causes many problems, mainly ash sintering, due to their low melting temperat...

Biofuels are more and more popular energy source and they are used in more households in the Eastern Europe region. Straw from the agriculture crops is promising and significant biomass source of energy but now it is at least energy utilized. In terms of straw burning is the most important feature of its quick and easy volatilization. Another prope...

Utilization of biomass for energy purposes is becoming more current and supported by almost the entire world. One form of the biomass is wood pellets. At present, one of the disadvantages of wood pellets using is their relatively high price. It is mainly caused by high price of input (starting) material – wood sawdust of good quality without bark c...

Possible solution to the increasing energy consumption in the world may be use of alternative energy sources in micro-cogeneration in combination with increasing energy effectiveness. The use of renewable sources, such as biomass, represents an important contribution to possible solution of this problem. When designing a new heat source it is requi...

Application additives into the material for the production of wood pellets achieve an improvement in some properties such as pellets ash flow temperature and abrasion resistance. Additives their properties influence the course of combustion, and have an impact on the results of issuance. The experiment were selected additives corn starch and dolomi...

Temperature as a primary aspect of the environment affects the drying process greatly. The temperature of drying air in a hot air drying depends on the temperature of the ambient air blown into the system. This temperature determines the drying time and energy consumption of the drying process. The work describes the effect of ambient temperature o...

Thesis deals with the measurement of performance and emission parameters of small heat source for combustion of biomass in each of its operating modes. As the heat source was used pellet boiler with an output of 18 kW. The work includes design of experimental device for measuring the impact of changes in air supply and method for controlling the po...

Phytomass, particularly wheat straw as a source of energy has countless benefits, but it has many problems in its direct burn too. The worst problem is the ash flow temperature. The aim of study was to analyze and reduce the problems of the wheat straw combustion. The experiment was conducted under realistic conditions. In this paper was implemente...

The paper deals about the problematic of energy properties of solid biofuels in comparison with solid fossil fuels. Biofuels are alternative to fossil fuels and their properties are very similar. During the experiments were done in detail experiments to obtain various properties of spruce wood pellets and wheat straw pellets like biofuels in compar...

The fireplace combustion of wood is a significant and largely unregulated source of emission pollution. Therefore article deals about experimental measurements of emission parameters from combustion of biomass in small heat sources. The objectives of the present work are to analyse basic pollutants arising from the combustion process and to define...

Biomass as fuel is used for many years. At present it is important to effectively use energy sources because price of energy is more and more expensive. This is the main reason for building of modern low-energy houses. The projected thermal performance of these buildings rarely exceeds 4-6 kW. During most days of heating season these buildings need...

Waste production is greater every year with society evolution. The same problem is also in Slovak republic, but Slovakia is significantly behind other developed countries in municipal waste management especially in area of energy utilization and recovery of the municipal waste. This problem will be totally reflected after the ban of the waste dumpi...

The article describes impacts of incinerating PET bottles and HDPE, LDPE bags in heat sources intended for combustion of solid fuels on emission load of environment. As primary fuel was intended brown coal and municipal waste was admixed in various amounts. The article describes the process of measuring and evaluating emissions during their inciner...

The paper presents a numerical model of heat transport from melting charge of the electric arc furnace designed for ferroalloy production, into a cooled roof of the electric arc furnace from which waste heat is led to the heating system of a company. The model considers the influence of an asymmetric flue gas removal and geometry of electrode arran...

Design of effective heat transfer devices and minimizing costs are desired sections in industry and they are important for both engineers and users due to the wide-scale use of heat exchangers. Traditional approach to design is based on iterative process in which is gradually changed design parameters, until a satisfactory solution is achieved. The...

Nowadays, the most used biofuel in Slovak republic is log wood. Alternatively, there are also biofuels based on vegetal biomass (phytomass) like wheat straw or grass. The advantage of these biofuels is lower cost price because they are usually considered as waste product. The major disadvantage of these vegetal biofuels is their problematic combust...

Woody biomass is an abundant, renewable energy source. Forest residue is the fraction remaining after harvest and the outtake of wood timber, including tree tops and bark. Compared with the wood portion, bark has a wide variation of ash content. Wood usually has a relatively low ash content, while bark has considerably higher ash content, which may...

Combustion of the solid fuel in the burner is an important issue when discussing the CFD simulation of combustion in automatic boiler. In the present work is employed a simplified method for modeling the fuel bed, which is based on mass and heat balances in order to simplify the simulation of combustion in pellet boiler. The model for solid fuel co...

It is relatively complicated to effectively burn biomass. Combustion of biomass fuel itself as a renewable energy source does not automatically ensure the best use of its energy content with low emission production. Biomass combustion with bad settings of combustion conditions can be ineffective and with a high production of emissions. The article...

The thermodynamic derivatives based on fundamentals thermodynamic space and physical parameters of natural gas influences other variables of pipeline systems such as pressure, temperature, velocity, density, gas compressibility, etc. These variables are crucial for gas pipeline system knowledge and its accurate operation. Fundamental parameters are...

The use of renewable energy sources in Slovakia is currently very debated issue. The main cause of this discussion is the increase of energy prices, which increasingly burden the population and companies. The use of renewable sources, including biomass, represents an important contribution to solve this problem. When new heat source is designed, se...

The paper presents a new criterion equation for calculating the Nusselt number for heat transport by natural convection from different numbers of cylindrical surfaces of heating sources. Horizontal cylindrical surfaces are situated one above the other and each of them is independently electrically heated by constant power output of Joule heating. C...

This article is focused on research into the effect of the position of directional tubing with respect to a shaped heating surface during free convection. Local heat transfer coefficients along a vertically shaped heating surface are defined in the material with changes in the position of the directional tubing. The contactless holographic interfer...

A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don't contain the bark and branches represent th...

The paper is aimed at the visualisation of temperature fields in the system of horizontal tubes arranged above each other to analyse heat transfer parameters. The experiments were carried out at the constant surface temperature of 323 K and free air convection. To carry out the experiment the method of holographic interferometry was used and experi...