Plant Boiler Research Articles

Problems of operating heating boilers of increased environmental efficiency

Purpose. Ensuring reliable operation of heating heat-generating devices with recirculation and exhaust gas heat recovery. Methodology. The normative methods of thermal calculation for surface heat exchange devices and the software according to the requirements of regulatory methods for this type of equipment for processing the results of our own experimental studies on heat exchange during deep cooling of combustion products of gas-consuming boilers were used. Findings. Calculation studies on the thermal operation modes during the heating period under the conditions of recirculation and heat recovery of flue gases of gas-fired water-heating boiler plants not equipped with air heaters were carried out. The main characteristics were determined of the thermal and humidity operation state for the air-supply ducts of these installations under the conditions of recirculation of flue gases’ part into the blown air. Regularities of temperature and dew point changes in the mixture of admixed gases and air under the conditions of using traditional heat recovery technologies and without them in different boiler modes and with different parts of recirculated gases were established. Problems of ensuring the operability and reliability of such boiler plants are highlighted. It is shown that these problems are related to condensate formation on the internal surfaces of air ducts and their freezing in some operating modes during in the cold period of the heating season. It is also shown that an effective solution to existing problems can be the use of air heaters in heat recovery systems to preheat the blown air before its mixing with recirculation gases. Originality. For the first time, the thermal and humidity operation modes of the air-supply ducts of heating boiler plants with increased environmental efficiency, which is ensured by boiler exhaust gases recirculation into the blown air, have been investigated. Practical value. The obtained research results will be used in the design of systems of recirculation and heat recovery of heat-generating devices’ exhaust gases to improve their environmental and thermal efficiency.

Energy-saving installation of a river vessel

This article relates to diesel engineering and can be used by design organizations and river fleet vessels in operation. The device of the energy-saving installation of a river vessel uses a heat pump with a high-temperature two-stage compressor and an Organic Rankine Cycle (ORC). In a two-stage compressor, the temperature of the low-boiling substance reaches 100°C. Further, this steam is condensed in the ORC condenser, while the coolant is heated to 95-98°C and the resulting coolant is distributed through a three-way valve: part of the coolant flow enters the heating object, the other part of the coolant enters the ORC evaporator through a three-way valve, where heat exchange with a low-boiling substance takes place. The resulting high-pressure steam then enters the turbine. In this case, the steam turbine is driven with a generator and electrical energy is generated. The proposed energy-saving installation can be used by river vessels during cargo operations and forced stops, during which the power plant: the main marine diesel engine, diesel generator and auxiliary boiler plant are inoperative, which leads to significant fuel savings of the ship power plant.

Harmonic Mitigation with Active Filter in Coal Boiler Plant PT. Salim Ivomas Pratama

Harmonic Mitigation with Active Filter in Coal Boiler Plant PT. Salim Ivomas Pratama

Internet of things (IoT)-based on real-time and remote boiler fuel monitoring system: a case of Raha Beverages Company Limited, Arusha-Tanzania

RAHA Beverages Company (RABEC) is one of the banana wine production companies that utilizes fuel in steam production in Arusha-Tanzania, where fuel data conditions such as temperature, pressure, discharge, fuel level, and gas leakage with humidity were a challenge to monitor, which provoked boiler malfunction and plant breakdown. Today, RABEC manually uses a dropping stick into the fuel tank to monitor fuel data conditions which is time-consuming and gives inaccurate readings, inefficiency, fuel economy discrepancy, and accidents. This study aimed to design and develop an IoT-based fuel monitoring system. The flow meter, ultrasonic level, thermistor fuel temperature, humidity, and pressure sensors were used to gather fuel information where the GSM module was employed to send fuel data messages to the operator’s phone. An AT mega 328 microcontroller was used to process and analyse the fuel data and send them to the Thing Speak IoT platform using Wi-Fi connectivity. The results showed that when the fuel level was less than the threshold value, an operator was alerted by a refilling message via GSM technology. A pressure of 0.1psi, a fuel temperature of 120 ℃, and 80% of humidity, the system notifies the operator by an alert message to check the injector pressure and if the fuel–air mixture is perfect. In addition, these data were observed on the LCD and ThingSpeak webpage. To conclude, the developed system proved the best performance with a 99.98% of success rate with high accuracy, security, and efficiency rate compared to the current monitoring system.

Innovativeness and Business Process Planning of Startups in the Context of Green Energy Transition

The aim of the artice. Taking into account the urgent need of rebuilding the national economy and energy system after the war destruction on the principles of green energy transition, it is extremely important to develop the startup movement in the field of alternative & renewable energy. The active implementation of the principles of an innovation-oriented circular economy requires significant and well-thought-out reforms in both economic relations and technology advancement. In this context, it is important to actively implement the concept of sustainable development, ensure the promotion of environmentally friendly goods and services on the market, and minimize the consumption of traditional fossil fuels, as well as the use of agricultural land for growing fuel crops. Thus, the purpose of the study is to analyze the innovativeness of business processes of national startups in the field of green alternative energy and to substantiate the peculiarities of business planning of environmentally friendly startup projects in the context of the green energy transition (also associated with the concepts of the renewable energy transition and the green deal). Analysis results. The paper explores business processes in the field of green startups, describes in detail the author's Bioenergy-Startup project, and substantiates its Business Model Canvas. The Bioenergy-Startup project has a positive environmental and economic effect and makes it possible to significantly reduce toxicant emissions from vehicle engines and diesel-fueled boiler plants. The project is also aimed at greening the country's economy by reducing the technogenic load on agricultural land through the use of fat-containing production waste, promoting the rational use of natural resources, and reducing greenhouse gas emissions, as well as the emissions of so-called black carbon. Using the Bioenergy-Startup project as an example, the authors proposed a framework for implementing a startup, starting from the creation of the Business Model Canvas and taking into account the levels of technological innovation and risks. In creating this framework, the authors took into account, in particular, the Customer Development and Lean Startup methodologies, the work of domestic scientists, as well as their own experience in the field of innovative entrepreneurship. During the implementation of the Bioenergy-Startup project, one of the main tasks from the marketing point of view was to create and communicate to the target audience significant competitive environmentally friendly advantages that are not only consistent with the concept of sustainable development and a green (circular) economy but also provide an opportunity to save valuable natural resources, promote the decarbonization of industry and transport, prevent climate change on the planet, etc. Conclusions and directions for further research. To accomplish this task, the authors have developed a marketing strategy for promoting the innovative products of the Bioenergy-Startup, as well as a specific algorithm for promoting the startup's innovative products, a schematic representation of which is given in the paper.

STUDY OF THE PROGRAMMABLE ISOKINETIC SAMPLER EFFICIENCY FOR OF ECOLOGICAL DIAGNOSTICS SYSTEMS OF HEAT ENGINES AND BOILER PLANTS

The work is devoted to the solution of the actual scientific and practical task of creating a universal sampling device for systems of environmental diagnostics of heat engines and boiler plants of various purposes. Ensuring the isokinetic mode of sampling from the exhaust pipe (EP) of the engine is a more difficult task than carrying out a similar sampling process in the chimney of the boiler plant, since the exhaust gases of the engines are characterized by fluctuations of static pressures in the HT with an amplitude of up to ±500 Pa, which must be taken into account in the operation of the sampling equipment. In the course of research, based on the analysis of global and domestic experience in the production and use of equipment for environmental certification of internal combustion engines and boiler houses, a programmable isokinetic sampler (ICT) was created, which allows you to take a proportional part of the gas sample from the full flow of exhaust gases in the EP of the power plant with accuracy ±3%. Motorless and motorized test stands have been developed for modeling and research of gas-dynamic processes in the exhaust systems of engines and boiler plants, which provide the possibility of varying the parameters of gas flows - mass flow rate, speed, temperature, static pressure, velocity pressure in the ranges: 15 - 55 g/s; 5...30 m/s, 20...180 °С, 0...2.5 kPa, 10 - 550 Pa, respectively. On the basis of the created test stands, empirical dependences were established to determine the static pressure differences between the ICP and EP pipelines, in which the isokinetic mode of sampling is ensured, from the dynamic pressure of the gas flow in the EP. With the help of these dependencies, SMART control of the programmable ICP is carried out. An experimental development of the programmable ICP was carried out as part of the MT-1 minitunnel during environmental tests of the 1СН12/14 diesel engine in separate modes and according to the ESC cycle established by the UNECE Regulations R-49. The research results confirmed the compliance of the created sampling device with regulatory requirements for its design and the accuracy of determining the sampling coefficient.

Reducing the Harmful Impact of Boiler Plants on the Environment

World production makes an ever-increasing harmful impact on the natural environment. As a matter of fact, mankind is facing the problem of saving the natural environment. As for the production branches the energy industry has the strongest harmful effect, and as for the production facilities the boiler plants that emit heat and harmful substances into the environment are the most environmentally aggressive. The global fleet of boiler plants is huge and complicated. As the boiler plant wears out, the levels of its environmental, economic and general technical efficiency are increasingly decreased, and the intensity of the harmful impact on the environment is increased worsening progressively its condition. The self-healing process of the natural environment lags behind the process of harmful effects on it. As a matter of fact, the problem of reducing the harmful effects of boiler plants on the environment has arisen. The purpose of this study was to analyze the phenomenon of interaction between the energy sector, primarily boiler plants and the natural environment and search for the ways to resolve the existing contradictions of this interaction. The task of improving the environmental friendliness of worn-out power equipment and, above all, boiler plants is an urgent issue. The purpose of this research paper was to analyze the possibilities of solving the problem of ecological interaction of boiler plants with the natural environment through their partial, full or redundant renovations. This research is relevant, because the boiler plants of the domestic fleet are extremely worn out. Full or redundant renovation is highly resource intensive and appropriate resources are currently unavailable. A realistic way to solve the problem of reducing the harmful effects of boiler plants on the environment is to increase the environmental friendliness of worn-out boiler equipment by partially upgrading it using relatively simple and affordable methods, such as normalizing the boiler air mode, reducing heat losses with exhaust gases, rationalizing and implementing daily and weekly schedules of the boiler operation in order to extend the full load carrying mode. Successful implementation of the forthcoming program of partial renovation of worn-out boiler plants will ensure a significant reduction of their harmful impact on the environment.

Monitoring of the floristic diversity of the Teremky Tract of the “Holosiivskyi” National Nature Park in the conditions of anthropogenic load

The article presents the results of monitoring the floristic diversity of the Teremky Tract, which is part of the “Holosiivskyi” National Nature Park as a separate territory. The tract is located in the city of Kyiv, directly adjacent to a large residential area and two highways. An analysis of the main factors affecting the ecological state of the territory was conducted. Among the main factors negatively impacting the state of the ecosystem of the Teremky Tract, the following can be distinguished: vandalism, which includes setting fire to old trees and causing various types of damage to them; plucking of flowering plants; environmental pollution with solid household waste; direct and indirect influence of hazardous objects such as boiler plants and gas stations; and the influence of transport infrastructure. The article demonstrates the need for constant monitoring of the ecological state of natural biotopes located within modern megacities. It is shown that the monitoring of floristic diversity, controlling the preservation of valuable and rare plant species, and tracking the appearance and spread of invasive alien species can be effective indicators of the ecological state of the natural biotope. Thus, populations of forest lily (Lilium martagon L.) and cuckoo’s tears (Listera ovata L.) were found on the territory of the Teremky Tract, which are included in the Red Book of Ukraine. Additionally, a group of 400-year-old oak trees grows in this area. However, the presence of invasive alien species such as red oak (Quercus rubra L.), the ash-leaved maple (Acer negundo L.), black cherry (Prunus serotina L.) and Robinia pseudoacacia L. was also observed. Monitoring of floristic diversity in natural biotope areas within megacities plays an important role in timely response to the effects of negative natural and anthropogenic factors for the preservation of the environment of these urban ecosystems. Such monitoring can be conducted both through field observations and using remote methods and analysis of global biodiversity databases such as iNaturalist and GBIF.

Bagasse dust exposure and chronic respiratory symptoms among workers in the Metehara and Wonji sugar factories in Ethiopia: a longitudinal study design

BackgroundEthiopia’s sugar factories are growing by creating job opportunities for thousands of workers with varying educational, professional and socioeconomic backgrounds. These sugar factories are a source of several hazards that...

Techno-economic assessment of Bi-directional Low Temperature Networks

This work presents an approach to determine the optimal design configuration and circulation temperature for a given Bi-directional Low Temperature Network (BLTN) using scenario analysis. BLTNs are capable of supplying both heating and cooling via a bi-directional network of ‘warm’ and ‘cool’ pipes. They feature decentralised network circulation pumps and building integrated heat pumps, permitting low pipe circulation temperatures and thereby enabling low-grade heat to be rejected into the network. As a case study, a BLTN layout was conceived for a small section of a university campus, currently served by a high temperature heating network with gas-based CHP and boiler plant heat sources. The proposed BLTN utilises a horizontal ground source array and considers future estimated cooling loads which must be served by the network, in addition to existing heating loads. After analysing different design configurations at various heating to cooling load ratios, the headline result from this study is that an ambient temperature design, without centralised ground source heat pumps to control the network temperature, represents the most cost effective option. This result, based on the levelised cost of heating and cooling (LCOHC) over a 50 year period, is consistent regardless of the heating to cooling load ratio for the system. Moreover, as cooling loads are increased, the ambient temperature design becomes increasingly cost-effective relative to other options.

OPERATION FEATURES OF ENVIRONMENTALLY EFFICIENT BOILER PLANTS OF MUNICIPAL THERMAL POWER ENGINEERING

The work is devoted to research on the improvement of thermal energy production technologies in gas-consuming heating boiler installations while improving their environmental performance and increasing the operation reliability. The work purpose is to study the heat and humidity modes of the air-supply ducts of boiler plants with exhaust gases recirculation systems into the blown air. The main objectives of the study are: to determine the thermal parameters of a heating boiler with a 2 MW heating capacity with a exhaust gases recirculation system mixed with blown air into its furnace space under conditions of using heat recovery technologies and without them; determination and analysis the heat and humidity parameters of this mixture in different operating modes of boiler plants. Known thermal calculation methods of boiler plants and data from our own experimental studies of heat transfer during deep cooling of boiler plant exhaust gases were used. The thermal calculation results of the heating boiler with a system for exhaust gas recirculation into its furnace space mixed with blown air are presented. The regularities of changes in the adiabatic combustion temperature and heat-humidity characteristics of the above mixture depending on the boiler heat load in different its operation modes during the heating period and the share of flue gas recirculation from 10 to 20 % were established. The research results show that the introduction of recirculation gases leads to a decrease by 150 – 250 °С of the adiabatic combustion temperature tad due to the need to consume fuel heat for heating the introduced ballast and the greater of the recirculation share s the lower the level of the indicated temperature. The research results also showed that gas recirculation causes insignificant (in the range of 0.5 – 4.7 °С) changes in the temperature of the boiler exhaust gases. Based on the data obtained, the change regularities in the heat-humidity characteristics (temperature and dew point) of the mixture of recirculated gases and air in different boiler operating modes during the heating period and under the studied recirculation shares were established. It is shown that recirculation causes condensate formation on the surfaces of air ducts in all operating modes of boiler and in some modes their icing is possible. To prevent these negative phenomena, it is necessary to apply measures to increase the temperature of the gas-air mixture by a value not less than Δtsum = 15 – 35 °С.

IMPROVING THE PERFORMANCE OF BOILER PLANTS DUE TO THE USE OF DIRECT AND REVERSE RANKIN CYCLES

To generate electricity from biofuels at heat and power enterprises of Ukraine, the direct Rankine cycle is used, which ensures the efficiency of energy transformation within  = 0.25-0.55. To improve the efficiency of fuel energy, use in boiler plants, it is also proposed to implement a reverse Rankine cycle scheme. Such a proposal is good to use in enterprises where there is a need for drying biomaterials. Instead of a separate boiler for drying processes, it is proposed to use the energy of water condensation from flue gases. In this case, the cost of electricity for the operation of the compressor is significantly less than the amount of heat obtained by condensing water from flue gases. The efficiency coefficient or COP of the reverse Rankine cycle can have values greater than one  = COP  3. The combination of direct and reverse Rankine cycles in the technological scheme of the boiler plant increases the efficiency of using primary energy sources. The paper analyzes the representation of energy as a combination of two components: the potential P and the dynamics D. The Leibniz model, in which the power N is represented as the product of the potential P and the dynamics D with the unification of the unit of measure Watt, allows calculating the efficiency of transformation processes of different types of energy. To improve the energy performance of boiler plants, further development of the Newton model is proposed, which makes it possible to calculate the process dynamism indicator – . In Newton's model, within the framework of one type of energy, the dynamism indicator is calculated – as the ratio of dynamics to the initial potential  = D / P. Dynamism  can be calculated as the reciprocal of the resistance R, provided that the units of measurement of the energy components – potential and dynamics are unified. To increase the efficiency of biofuel combustion energy use, the idea of the reverse Rankine cycle has been implemented. The moisture condensation temperature of the flue gases increases due to an increase in the pressure of the medium. To do this, the smoke exhauster is moved from the discharge zone to the pressure zone. The additional energy from the flue gases of the boilers can be used to increase the efficiency of drying biomaterials. It is possible to refuse an additional boiler for drying materials, which significantly reduces fuel costs, and also improves the environmental performance of technological processes.

Risk management framework and practices for boiler operations in Malaysia

Boiler operations had a reputation for being one of the most hazardous work environments. Workers in the boiler plant face many safety risks due to the nature of the job. The work environment is often hot and noisy, consisting of several major equipment and operations involved in its process, and there is always a risk for crushing injuries, electrical shocks and burns, boiler fires and explosions, and contact with hazardous chemicals. Numerous activities performed in boiler operations are complex; these operations are hazardous and can cause accidents. This study aims to develop and propose risk management frameworks for working in a hazardous working environment at the boiler plant in Malaysia to prevent and control accidents and implement adequate safety and health management. Next, to analyze the risk factors and hazards for boiler operations based on the nature of work at the boilers in Malaysia using several methods: Bowtie Risk Assessment, Hazard and Operability Study (HAZOP), Failure Mode and Effect Analysis (FMEA). The result showed that the rate based on hazard sources in the boiler division has Extreme Risk levels (8%), High (14%), Medium (35%), and Low (43%). Risk assessment based on the type of hazard in the boiler division has risk levels ranging from high to the lowest score is the danger of Mechanical (25%), Electrical hazard (10%), chemical hazards (6%), and physical hazards (59%). The developed risk management framework with enhanced risk assessment techniques may solve the integration of sustainability aspects in boiler operations safety and risk management.

Techno-Economic Analysis of Co-firing for Pulverized Coal Boilers Power Plant in Indonesia

The utilization of co-firing (coal-biomass) in existing coal-fired power plants (CFPPs) is the fastest and most effective way to increase the renewable energy mix, which has been dominated by pulverized coal (PC) boilers, particularly in the Indonesian context. This study aims to investigate the technical and economic aspects of co-firing by conducting a pilot project of three PC boiler plants and capturing several preliminary figures before being implemented for the entire plants in Indonesia. Various measured variables, such as plant efficiency, furnace exit gas temperature (FEGT), fuel characteristic, generating cost (GC), and flue gas emissions, were identified and compared between coal-firing and 5%-biomass co-firing. The result from three different capacities of CFPP shows that co-firing impacts the efficiency of the plant corresponding to biomass heating value linearly and has an insignificant impact on FEGT. Regarding environmental impact, co-firing has a high potential to reduce SO2 and NOx emissions depending on the sulfur and nitrogen content of biomass. SO2 emission decreases by a maximum of 34% and a minimum of 1.88%. While according to economic evaluation, the average electricity GC increases by about 0.25 USD cent/kWh due to biomass price per unit of energy is higher than coal by 0.64×10-3 USD cent/kcal. The accumulation in the one-year operation of 5%-biomass co-firing with a 70% capacity factor produced 285,676 MWh of green energy, equal to 323,749 tCO2e and 143,474 USD of carbon credit. The biomass prices sensitivity analysis found that the fuel price per unit of energy between biomass and coal was the significant parameter to the GC changes.

Ресурсы ветра западного сектора Арктической зоны Российской Федерации и возможные направления их использования

The authors consider the potential and technical resources of wind energy in the Western sector of the Arctic zone of the Russian Federation. They have stated that increased wind speeds take place in the Arctic coastal areas. Their average annual values ​​at a height of 10 m reach 6—8 m/s. The strongest winds are observed in winter. It is during this period that the demand for heat and electricity from all categories of consumers is maximum, which is a significant prerequisite for the use of wind energy. On the example of the Murmansk region, the authors show the prospects for the use of wind-driven power plants (WPPs) for the production of electricity as part of the Kola electric power system, where there are 17 hydroelectric power plants that can compensate for the variability in the supply of wind energy. Promising is the joint work of WPPs with diesel power plants and boiler plants. The positive effect of such work is expressed in saving the imported fuel and reducing harmful emissions into the environment. The authors propose promising sites for the construction of energy complexes focused on the production of environmentally friendly hydrogen through the use of high-potential wind resources.

Evaluation of the cost-effectiveness of solutions to improve the efficiency of atmospheric deaeration in boiler plants

The reliable and economical operation of equipment for thermal power plants, heat supply systems and boiler houses has been a relevant problem in the field of thermal power engineering for many years. In many industries, industrial steam is often used, for which steam boilers are used at thermal power plants. The water consumed by the boilers undergoes pre-treatment, which, in addition to its softening, includes thermal deaeration — the removal of aggressive gases that lead to equipment corrosion. Atmospheric deaerators are often used for this purpose. They are easy to use, quite effective, but have a disadvantage — a considerable amount of heat is lost with the removed flash steam. The article is dedicated to evaluating the cost-effectiveness of the technology for additional heating of return system water using deaerator steam and considering a method for improving the efficiency of atmospheric deaeration by partial closure of flash steam output in boiler plants. The paper presents a calculation of the scheme of operation of a deaeration plant, which makes it possible to increase the efficiency and effectiveness of the boiler house of the AB InBev Efes brewery in Ulyanovsk due to additional heating of return system water with atmospheric deaerator flash steam. The article also discusses the scheme of operation of an atmospheric deaerator, in which the flash steam will be discharged into the atmosphere only if it is necessary to remove aggressive gases. Thanks to the developed scheme, when the deaerator operates with a closed flash steam removal pipeline and without being fed with chemically purified water, the consumption of industrial steam is reduced, especially with a significant return of condensate, which increases the efficiency of the entire boiler room as a whole. According to preliminary calculations, assuming the average return of condensate from production per day of about 300 m3, the production steam savings will be 0.8 tons.

INCREASING THE EFFICIENCY OF BOILER PLANTS WITH FLUE GAS RECIRCULATION AND DEEP HEAT RECOVERY

The thermal calculation results of a heating boiler plant with recirculation and heat recovery of flue gases are presented. The thermal efficiency of the complex heat recovery system use designed for heating the return heat-network water and blown air is investigated. Various options of flue gas selection for recirculation into the blowing air are considered, namely: after the boiler, after the water-heating heat recovery exchanger and after the air-heating heat recovery exchanger. The changes in the temperature of the exhaust gases regularities of the studied boiler plant various elements in the case of using the considered options for recirculated gas selection under conditions of changing their share in the air-gas mixture from 10 to 20 % and the relative heat load of the boiler from 30 to 100 % were established. Under these conditions, the levels of increase in efficiency in all elements of the boiler installation and the total efficiency with and without the proposed heat recovery system were determined. It is shown that the use of this system provides deep cooling of exhaust gases in the heat recovery process. The lower the temperature of the flue gas admixed in the options considered and the higher the share of gas recirculation, the lower the temperature of the exhaust gases for all elements of the boiler plant. The increase in the boiler plant efficiency due to the use of the proposed heat recovery system varies from 3 to 5 % in the case of a water-heating heat recovery exchanger and from 1 to 3 % in the case of an air-heating heat recovery exchanger, depending on the boiler load, the part of admixed gases and the options of their selection. The resulting increase in the boiler plant efficiency with a heat recovery and flue gas recirculation system is 1.4–4.7 %.

Paraffinic oil residues after heating as a basis for fuel

The possibility of reuse of heavy residues (oily sludge) of low-sulfur, highly paraffinic Mangyshlak oils as a basis for fuel with improved environmental characteristics for engines to marine, river and railway transport, gas turbine and boiler plants, steam boilers and industrial furnaces was shown. A variant of the joint application of the methods of nuclear magnetic resonance, laser confocal microscopy and rheology for study of micro- and mesoscopic structure and some physicochemical properties of crude oil products has been developed. It has been shown that preliminary heating to 90 ° C leads to disruption of the structure and hydrogen bonds between oil associates and complexes, increasing sample homogeneity due to precipitation of solid impurities, partial removal of water content, air bubbles and dissolved gases. The addition of medium distillate diesel fractions to preliminary heated oil residues will make it possible to obtain a higher quality version of the fuel with a reduced resinous and asphaltene substances, lower pour point, good energy content and low sulfur content. Thus, valuable energy-containing raw materials can be reused. It should also be noted that the reuse of accumulated oil waste will reduce the harmful effects of landfills, will preserve the natural landscape, and will cut the cost of extracting natural resources.

THERMAL ASPECTS OF HEATING BOILER PLANTS OPERATION WITH HEAT-RECOVERY AND EXHAUST GAS RECIRCULATION

The feature analysis of application for heating boiler plants of relatively small heating capacity, which are not equipped with air heaters, of the method of reducing the emission of nitrogen oxides due to decrease the temperature in the boiler furnace by recirculating exhaust gases into the blown air are presented. At the same time, heating gas-consuming boiler plants with traditional heat recovery systems of exhaust gases and implementation of this method with the selection of recycled gases after the boiler and heat-recovery exchanger are considered. The study results for a water-heating boiler with a heating capacity of 2 MW of the change regularities of the combustion temperature in the boiler furnace, the its exhaust gases temperature and water heated in the boiler as well as the boiler efficiency, depending on its relative heat load changed (from 30 to 100%) and with different parts of recirculated gases (from 10 to 20%) in the mixture with the blown air are presented. The studies were performed with and without them recirculation and heat recovery of flue gases. The research results show that the use of waste gas recirculation causes a noticeable decrease (by 150 – 250°C) in the combustion adiabatic temperature and a slight (by 0.5 – 4.7°C) decrease in the boiler waste gases temperature. Recirculation also leads to a decrease in boiler efficiency by 1.3 – 3.1% during the heating period, and the use of the considered heat recovery system of boiler waste gases with heating of return heat-network water by cooling them provides an increase in boiler efficiency by 2.5 – 8.1%. The resulting increase in boiler efficiency with a heat recovery and recirculation system is 0.1–4.8%.

Increasing the Operational Reliability and Efficiency of Boiler Plant Equipment of Thermal Power Stations by Improving the Quality of Measuring their Technological Parameters.

Increasing the Operational Reliability and Efficiency of Boiler Plant Equipment of Thermal Power Stations by Improving the Quality of Measuring their Technological Parameters.