Boiler Water Research Articles

21 Bar Yoshimin Boiler Maintenance with Controlling Residual Phosphate

Boiler as the steam generator is usually utilized as a turbine drive and other industrial processes. Boiler needs good treatment and surveillance to keep its best performance. Boiler water (BW) and boiler feed water (BFW) quality control is essential in boiler maintenance since it preserves boiler from crust, corrosion, and carry over, moreover, it also prevents boiler pipe to break. Boiler maintenance in sugar refinery factory is carried out by controlling the quality of BFW, Chemical injection (inner maintenance) and blowdown of boiler water. BFW mineral content (SiO 2 , total hardness) is maintained as small as possible using a softener (cation resin) or demineralization unit (cation and anion resin). Chemical injection is performed by the addition of soda in order to control the pH of boiler water. Phosphate addition aims to tie up total hardness level which is caused by concentration process of water boiler and slipped of hard water from BFW. Blowdown process has purpose to reduce crust and corrosion caused by mineral concentrate inside boiler. The experiment was conducted by controlling pH of BFW from 7.5-8.5, maximum total hardness at 3 ppm, maximum SiO 2 concentration at 3 ppm and maximum Total Dissolve Solid (TDS) at 100 ppm while BW was controlled its pH at 10.5-11, maximum total hardness at 20 ppm, maximum SiO 2 concentration at 50 ppm, maximum Total Dissolve Solid (TDS) at 2000 ppm, and residual phosphate ion between 4 – 10 ppm. The experiment time was adjusted as a milled day or about for 140 days. The result of the experiment showed that the treatment had a good impact on the condition of the boiler drum pipe.

Development of a Loss Method for Energy and Exergy Audit of Condensing Hot Water Boilers

Abstract Condensing boilers are used in commercial and residential buildings extensively. In this article, a loss method is proposed to estimate the energy and exergy efficiencies of condensing hot water boilers. The presented method is based on the development of the method presented in ASME PTC 4.1. Energy loss terms consist of exhaust flue gas, carbon monoxide formation, radiation, and condensate outflow sensible heat. Exergy loss terms also include radiation losses, physical exergy of the exhaust flue gas, chemical exergy of the exhaust flue gas, increase in the chemical exergy of the flue gas due to carbon monoxide formation, condensate outflow exergy, boiler exergy destruction, and economizer exergy destruction. Energy and exergy efficiencies are calculated by estimation of these loss terms. To depict the method’s capability and compare results with the direct method, an experimental setup was designed and constructed. Results of energy and exergy audition of the boiler by applying the loss method are compared with the direct method. The results show that, although the condensing economizer improves energy efficiency, it does not improve the exergy efficiency significantly. The energy and exergy efficiencies were 98.65% and 5.14%, respectively.

Optical fibre long period grating based chemical sensor for the analysis of silica in boiler water

Silica deposits in turbine blades, boiler tubes and cooling water circuits lead to serious loss in efficiency of power plants. Hence silica deposition is one parameter that is seriously monitored i...

Optical fibre long period grating based chemical sensor for the analysis of silica in boiler water

Optical fibre long period grating based chemical sensor for the analysis of silica in boiler water

A Study of Boiler Water Level System with Fuzzy Control Method

A Study of Boiler Water Level System with Fuzzy Control Method

Failure analysis of SA210-C steel pipe in power plant

The reason and mechanism of the failure of SA210-C steel liquid wall were analyzed by means of macro morphology analysis, chemical composition analysis, microstructure analysis and XRD phase analysis. The test results show that the main reason for the failure of SA210-C steel water wall tube is the corrosion under the inner wall scale, and the long-term unqualified boiler water quality is the main factor causing the corrosion of water wall.

Study of the efficiency of energy use of willow chips and torrefied hydrolytic lignin pellets

The lack of raw materials to provide power plants with biofuel requires the search for new energy sources. In the European North of Russia, it is recommended to grow plantings of the willow (Salix L.) in the form of trees or tree-like shrubs, while ensuring a short interval between fellings. The studies show that the artificial cultivation of willow plantations on postagrogenic lands is economically more expedient than the exploitation of natural willow forests. This study examines the energy efficiency of willow wood, which is necessary when planning its use for the production of biofuel (wood chips or fuel pellets) and pellets obtained from torrefied hydrolytic lignin. A comprehensive study of the energy efficiency of willow chips, willow chips with bark, hydrolytic lignin pellets during the operation of the “Firematic 60” hot water boiler was carried out. The elemental composition of the fuels and the resulting ash was studied using an EDX-8000 X-ray fluorescence spectrometer and a Euro EA-3000 analyzer. The components of the heat balance and emission of harmful substances were determined. The emissions of particulate matter and the content of soot particles were studied.

Studies on densification and conversion of wastes as fuel briquettes for power generation

Energy in the world is on high emergency now days. Energy resources are abundant but exhausted as per present conditions. Search for alternate energy sources has been trending worldwide. Solar and wind energies are of present interest to minimize cost of investment. But utilization of Municipal and Solid waste as an alternate source of energy is vital in research. Producing fuel briquettes with naturally available waste materials which are biodegradable is an asset. The experimentation is carried out for moisture content, ash content, volatile matter, fixed carbon, sulfur, calorific value and water resistance. The waste materials are mixed with all purpose flour in different ratio’s. Calorific value is evaluated based on ultimate analysis. The effects of various parameters as fuel briquettes for power production were measured of data consisting of characterization (FTIR and XRD), Analysis of materials (Proximate and Ultimate) and Estimation of properties for fuel briquettes (Calorific value, porosity, waster absorption, shatter index, compressive strength, optimization of materials quantity using Response Surface Methodology, Tumbling test, Degree of Densification, Water Boiler Test–Thermal Efficiency, Power Estimation and Power Calculated). The experimental data are obtained by conducting batch experimentations. In the present investigation, the prospective of four materials (leaves) namely red sandal, Wrightiatinctoria, teak and mixed leaves were evaluated to estimate their performance as fuel briquettes for the power production. The result of four biomasses wastes are in fact potential sources of energy which has been validated by the quite substantial amounts of briquettes obtained using these as raw materials and fuel briquettes have environmental benefits that include reduced tree degradation, better management of waste and reduced emissions.

The Main Directions for Improving the Efficiency of the Power Equipment of a CHPP

The article discusses matters concerned with rational use and improvement of the thermal efficiency of operating combined heat and power plants (CHPPs) that form a power and heat generation system under real operating conditions. Factors influencing the CHPP performance indicators, including design solutions, the extent of equipment wear in the course of operation, which is connected with deviations of operating modes from their design parameters, etc. are analyzed. It is shown that decreasing the electricity production by T and PT turbines operating in the condensing cycle, increasing the supply of heat from the uncontrolled extractions of high-efficient condensing turbines, and modernization of the equipment and thermal cycle circuits are an important reserve for improving the thermal efficiency of the operating CHPPs. The specific generation of electricity by CHPPs operating in the cogeneration mode is compared for CHPPs equipped with T-250/300-23.5, T-185-12.8, T-100/110-12.8, and T-175/210-12.8 cogeneration turbines and for various solutions on applying gas turbine units (GTUs) at gas-fired CHPPs, including those containing hot-water boilers heated by exhaust gases, including the version of the fully variable combined cycle plant (CCP) for a capacity of 20–25 MW developed at the All-Russia Thermal Engineering Institute. Modern thermal cycle circuits and calculation methods used in designing the modernized flow paths of CHPP steam turbines are presented. The necessity of applying a systems approach in elaborating the requirements for modernizing particular CHPPs by optimizing the structure of generating capacities is pointed out. Recommendations on improving R and TR turbines (with cogeneration back pressure) and uncontrolled steam extractions from large-capacity condensing turbines are formulated with due regard to the systems approach. The article points out the advantages of electricity generation in the CCP condensing cycle, the effectiveness of domestically produced power-generating GTUs with the electrical capacity equal to 16 or 25 MW equipped with heat-recovery hot water boilers or CCPs equipped with these turbines (provided that gas fuel is available for newly constructed capacities), and also limited scales in which the commissioning of cogeneration CCPs is advisable in areas containing large heat loads.

The Use of Information Systems for Regulation of Gas Engine Operating Parameters

The purpose of the work is to indicate the possibility of using selected IT systems to analyse work and regulate operating parameters of gas engines. An additional task of the work is to indicate new possibilities of using IT systems in power plants. The publication shows the development of industrial information systems in recent years. It is shown how these systems are used for direct control and adjustment of operational parameters of power equipment, ranging from water boilers to steam boilers, turbines and cogeneration aggregates. These systems implement technical safeguards and can be used to analyse work characteristics in an appropriate configuration. The more elaborate energy systems, the wider the scope of use of IT systems. Due to the full automation and control of cogeneration gas-powered power generators, an automatic heating water flow control system through heat exchangers can be used in these installations. This solution requires the expansion of the heating water pumping system with pumping sets with inverters and fittings of the pumping station with remote control.

Mathematical Models for Assessing the Thermal Engineering Reliability of Boiler Units of Power Complexes

The analysis is carried out and the definitions of the concept of thermal engineering reliability, the determining parameter and the determining function of boiler units, are given. A classification has been developed for the determining parameters of steam and hot water boilers by level in the chain of cause-and-effect relationships in the event of a thermal failure. It is proposed to divide the determining parameters and functions of boilers according to their spatial localization into integral and local. A lot of models for defining functions with different mathematical properties (for example, the presence or absence of discontinuities of the second kind) are considered. The defining functions (reliability criteria) currently used in boiler construction have been identified. The analysis of the safety factors for overturning and stagnation in direct-flow and drum boiler units is carried out. The incorrectness of the currently used dependence is shown. A formula has been proposed for these coefficients using internal useful heads, which is especially relevant for boilers with natural circulation at ultrahigh pressure.

Оптимизация работы теплофикационной насосной станции ТЭЦ

The article describes the optimal algorithm for controlling a group of pumps equipped with frequency controllers, which gives great savings and allows to completely eliminate throttle regulation in the network, as well as realize a new principle of protection of hot water boilers from a decrease in water pressure, which is necessary for the implementation of the above algorithm.

Burner development for efficient combustion of biogas

Now in metallurgical production energy resources demand is almost completely satisfied by gaseous fuel. Biogas obtained during organic waste processing is considered as an alternative and cheaper type of fuel. The experience of biogas application has shown that in most modern burners decrease of efficiency and limitation of the range of load regulation is observed. To apply biogas in an industrial environment, it is necessary to develop burners and the methods of its combustion, which provide a high combustion efficiency, as well as a higher energy conversion efficiency. The authors have used the results of gas analysis of biogas obtained in the process of anaerobic decomposition process of organic waste in the reactors of a bioenergy plant. Methods of mathematical statistics with the use of regression analysis of experimental data were used to assess the indicators of the energy efficiency of the gas burner. The possibility of using biogas and landfill gas in the process of roasting, blast-furnace smelting, production of rolled products and steel, as well as heat treatment of metal has been experimentally proven. The properties and composition of biogas at the outlet of the methanogenesis reactor of the bioenergy plant “EcoVoltAgro” are described. A new design of a gas burner is proposed. In this model the efficiency of mixture formation and the completeness of combustion of the flow of a methane-containing gas mixture are significantly increased (up to 32 %) due to the effect of rotation of the perforated pipelines of the gas inlet pipe. On the basis of the results of the full-scale experiment, the optimal values of the gas-air mixture supply rate, the temperature of the supplied air, the volume fraction of methane were determined in order to obtain the largest width of the zone of deviations of the permissible concentrations of carbon dioxide. The use of the designed gas burner provides energy-efficient combustion of biogas in metallurgical furnaces, kilns, and dryers, as well as in any steam and hot water boilers.

Combined scheme of solid fuel combustion in low power boilers

Different constructive schemes of solid fuel combustion in heating boilers up to 100 kW with the analysis of their efficiency depending on the quality of the burned solid fuel are considered. It is established that low-power solid fuel boilers with various types of combustion devices depending on the characteristics of the burned fuel and the accepted level of service are used in heat supply systems of premises, buildings and structures: from simple furnaces with manual maintenance to automated combustion devices of complex design. Mostly pre-prepared high-quality fuel is used for combustion: fuel pellets, briquettes, high-quality coal, the high cost of which significantly increases operating costs. In order to reduce capital and operating costs, it is advisable to introduce relatively inexpensive models of low-power heating boilers with an acceptable level of mechanization of combustion technology of cheap fuel, including local, with minimal costs for its preparation. The design of a heating water boiler with a semi-mechanical furnace and a technological scheme of combustion is proposed, which combines the processes of drying, gasification and combustion of fuel in a shaft with a clamping grate and combustion of coke in a layer on a moving grate. It is noted that the periodic supply of fuel in the furnace with a moving grate is maintained the stability of the combustion process in the combustion chamber, in the period between cleaning of ash and slag, without significant changes in the composition of above-layer gases. Due to the smooth movement of the next portion of hot coke from the fuel shaft to the combustion chamber on the rotating grate, conditions are created to maintain the uniformity of the boiler with the normative indicators. A reduction in harmful emissions in the exhaust gases was achieved during the combustion of the reaction fuel by passing a secondary blast of air through a collector and directing it to the combustion zone of light substances at the outlet of the clamping grate. Analytical equations for determining the size of the combustion zone according to the regime and design parameters of the combustion process are given. The efficiency of application of the combined (shaft-layer) technological scheme in low-power boilers was tested during testing of combustion of different quality coal in a semi-mechanical furnace with a rotating grate in the electric coal boiler with a heat output of 50 kW for railway carriages.

Investigation on the welding-induced multiple failures in boiler water wall tube

In this study, by performing visual inspection, chemical composition analysis, mechanical performance testing, micro-structure and micro-morphology analyses, a failure investigation is presented on the surfacing weld induced bursting of 20G water wall tube in a thermal power plant. Besides, to identify the environmental medium and deposits, the Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction (XRD) have been conducted. The tube has undergone the localized wall thinning by fly-ash erosion burst after being repaired for 4000 h. As revealed from the macroscopic examination on the tube, significant corrosive products have been produced on the water-side of the surfacing layer position of the tube. According to the metallographic analysis of the rupture region, the massive widmanstatten overheated structure has been found in the heat-affected zone (HAZ). Furthermore, in the failure parent metal, extensive intergranular cracks, severe decarburization and mechanical performance degradation (∼20 HV10) have been identified. The micro-morphology analysis has described the partial-melting process, spherical particles and the dendrite on the fracture surface. As revealed from the EDS and XRD results, the accumulation of Cu on the inner surface of the rupture region of the tube was demonstrated. The comprehensive study has suggested that the excessive welding heat-input leads to the generation of local over-heating and over-burning. Lastly, the electrochemical corrosion and the hydrogen corrosion cracking are generated in the inner wall of the welding region.

RESEARCH OF COMBUSTION MODES DURING LAYER-BURNING OF SHUBARKUL COAL ON THE FIRE GRATE WITH THE HAND FURNACE OF THE KSVR-0.43 HOT WATER BOILER

Experience shows that the trend towards using solid fuels in the energy sector of Kazakhstan will be implemented for a rather long time. At the same time, the global trend is currently tightening environmental requirements. They set the task to continue improving coal combustion efficiency and minimize emissions of harmful substances and greenhouse gases into the atmosphere. This article aims to conduct complex thermal engineering tests of the KCVr-0.43 hot water boiler. For this, the following measurement and control tools were used: the standard boiler room secondary devices, an industrial gas analyzer Testo-350, a control (reading) module Testo-454 with temperature probes and a Pitot tube, a soot number meter Testo-308, a temperature meter 2TPM1, a portable liquid flow meter Vzlet-PRC and a stopwatch. All they had valid verification and calibration certificates. An analysis of the gas composition and technical parameters of the KCVr-0.43 hot water boiler in the investigated operation mode with Shubarkul coal during a long-term test showed that it seems possible to operate boilers of this series under low load conditions without boosting air and fuel. They can reduce emissions of toxic NOx and greenhouse gases CO2 into the atmosphere. In this case, burning Shubarkul coal without forcing through the air is characterized by significant carbon monoxide CO emissions. The formed nitrogen oxides NOx decompose in reactions with CO with the formation of molecular nitrogen and oxygen. Burning, coke residue in the layer, coal-burning stages, emissions of harmful substances.

PRIMER PRIMENE ISO STANDARDA 14001:2015

Standard ISO 14001 danas je naj­rašireniji međunarodno prihvaćen standard za uprav­ljanje životnom sredinom. Implementacijom ISO 14001 utvrđuje se koji od procesa u kompaniji zagađuju životnu sredinu, određuju se realni ciljevi i uvode se neophodne mere koje podpomažu ostvarenje ciljeva. U radu je opisana procena rizika zagađujućih materija u vazduhu toplovodnih kotlova u JKP „Novosadska toplana”. Cilj rada jeste da se prikažu dobijeni rezulzati analize procene rizika primenom ISO standarda 14001:2015.

Optimization and sensitivity analyses of a combined cooling, heat and power system for a residential building

In the quest for a better use of energy resources, energy integration, and cogeneration strategies have been employed in the industrial and commercial sectors with considerable benefits realized. However, the residential sector remains underexplored. An optimization procedure should be carried out whenever there is a need to ensure or verify the economic viability of an energy system. This study uses Mixed Integer Linear Programming to optimize the energy supply to a residential building, with 20 floors and 40 apartments, located in the city of Joao Pessoa (northeast Brazil). The equipment available includes gas engines, electric and natural gas boilers, heat exchangers, cooling towers, and absorption and mechanical chillers. The optimization establishes the optimal system configuration and operational strategy (operation throughout the year). Economic, technical, and legal aspects were considered in the minimization of the total annual costs associated with the building?s energy supply. The energy demands were calculated on an hourly basis, throughout one year, by the EnergyPlus software and corresponded to hot water (83 MWh per year), electricity (171 MWh per year), and cooling (242 MWh per year) demands. The optimal system was entirely reliant on the electric grid to meet the electricity demand directly and to satisfy heating and cooling demands by means of an electric hot water boiler and a mechanical chiller. The optimal solution is tested by varying, within reasonable limits, selected parameters: natural gas and electricity tariffs, the behavior of residents, amortization factor, and relationship between the tariffs of electricity and natural gas.

Implementation of water chemistry in fossil power plants with drum boilers and in combined cycle/HRSG plants

Current water chemistry practice at fossil power plants with drum-type boilers and heat recovery steam generators includes ammonia dosing into the feedwater train and sodium phosphate or sodium hydroxide into the boiler water. The issues and impact on equipment with the use of phosphate or sodium hydroxide boiler water treatment, as well as optimum conditions for the use of these chemicals are discussed. Another operational issue of boiler unit is associated with flow-accelerated corrosion (FAC) of material, especially in the low-pressure circuit. The major reasons for boiler failures are outlined, with the data on FAC failure locations. An effect of oxygen and ammonia on boiler corrosion processes is discussed.

The Exploitation of Low-Temperature Hot Water Boiler Sources with High-Temperature Heat Pump Integration

The article presents an original and innovative technical solution for the exploitation of low-temperature excess heat from hot water boilers that use gas or liquid fuel for the needs of high-temperature heating in buildings or in industry. The primary fuel efficiency used for hot water boilers can be significantly increased by utilizing the excess low-temperature heat of flue gases that are discharged into the environment and thus also reduce CO2 emissions. Hot water systems usually operate at higher temperatures of the heating water, which is transported to the heat consumer via supply pipe, and the cooled heating water is returned to the hot water boiler via the return pipe. For the excess low-temperature heat exploitation of the flue gases from hot water boiler, it is necessary to install a condenser in the flue gas discharge pipe, where condensation of water vapour present in the flue gas heats water or a mixture of water and glycol. The heating water, which is cooled and returned from the heat consumer via the return pipe, is led to the condenser of the high-temperature heat pump, where it is preheated and then led to the hot water boiler, where it is heated to the final temperature. A computer simulation with the Aspen plus software package for the series or parallel connection of high-temperature heat pump to a hot water heating system and the economic analysis of the excess heat exploitation from the flue gases are also performed.