Boiler Efficiency Research Articles

Online Coal Identification Based on One-Dimensional Convolution and Its Industrial Applications

In order to improve the utilization rate of coal generation and reduce carbon emissions from coal-fired boilers, the operation parameters of power plant boilers should be matched with the actual burning coal. Due to the complex and high-risk blending process of multiple coal types, the actual application of coal types inconsistent with expectations may lead to low combustion efficiency of boilers, cause disturbances to the normal operation of thermal power units, increased energy waste and carbon emissions, and even lead to serious explosion accidents. Therefore, the online identification of coal types for thermal power units is of great significance. To obtain the precise type of coal online, in the present work, a data-driven coal identification method is proposed based on convolutional networks that do not necessitate additional hardware detection equipment and are easy to implement. Experimental results indicate that the proposed method exhibits superior performance in comparison to traditional methods, thus ultimately improving the performance of thermal power plant.

A hybrid receding horizon optimization and active disturbance rejection control of boiler superheated steam temperature

Efficient control of superheated steam temperature is critical for maintaining the safety and efficiency of a power plant boiler. Exceeding the safe temperature range can cause irreversible damage. However, unknown disturbances and uncertainties, as well as large delay dynamics, often make superheated steam temperature safety control challenging. To this end, this paper proposes a hybrid bi-level safety control for superheated steam temperature control in a power plant boiler. The bottom level uses active disturbance rejection control, while upper level uses receding horizon optimization. The proposed method combines the advantages of active disturbance rejection control in solving unknown disturbances and the dynamic optimization of receding horizon optimization to effectively and safely control superheated steam temperature and optimize the control system performance. The main novelty of the scheme lies in making receding horizon optimization independent of the model of the plant, in terms of making full use of the closed-loop desired dynamics under active disturbance rejection control. Practical synthesis design methods are also presented to illustrate the tuning and optimization of this control strategy. On-site testing results show that the proposed method improves both disturbance rejection and tracking performance, with improvements of at least 20 % over comparison methods. In conclusion, the proposed bi-level control strategy is a promising approach for improving the safety and efficiency of power plants.

Regional impacts on air quality and health of changing a manufacturing facility’s grid-boiler to a combined heat and power system

ABSTRACT Poor air quality is linked to numerous adverse health effects including strokes, heart attacks, and premature death. Improving energy efficiency in the industrial sector reduces air emissions and yields health benefits. One of these strategies, replacing an existing grid boiler (GB) with a combined heat and power (CHP) system, can improve a facility’s energy efficiency but can also increase local air emissions, which in turn can affect health outcomes. Previous studies have considered air-emissions and health outcomes of CHP system installation at a single location, but few studies have investigated the regional air quality and health impacts of replacing an existing GB with new CHP system. This study estimates the emission changes and associated health impacts of this shift in 14 regions in the US, representing different electricity generation profiles. It assumes that one manufacturing facility in each region switches from an existing GB to a CHP system. The monetized annual US health benefits of shifting a single GB to a CHP in each of the 14 regions range from $-5.3 to 0.55 million (2022 USD), while including CHP emission control increases the benefits by 100–170% ($9,000 to 1.15 million (2022 USD)). This study also includes a sensitivity analysis, which suggests that the facility location (region, state, and county), boiler efficiency, and emission control of the CHP are key factors that would determine whether shifting from a GB to CHP system would result in health benefits or burdens. Implications: Combined heat and power (CHP) systems offer industrial facilities the opportunity to improve their energy efficiency and reduce greenhouse gas emissions. However, CHP systems also combust more fuel on site and can also increase local air emissions. This study evaluates how converting an existing grid boiler (GB) system to a CHP system (with or without emission control) affects local (from combustion) and regional emissions (from electricity consumption) and the associated health burdens in different US regions. A facility can use this study’s analysis as an example for estimating the tradeoffs between local emission changes, regional emission changes, and health effects. It also provides a comparison between the incremental cost of adding SCR (compared to uncontrolled CHPs) and the NPV of the monetized health benefits associated with adding the SCR.

Preliminary Results of Innovative Two-Stage Torrefaction Technology Applied for Thermochemical Treatment of Sunflower Husk

This article proposes an innovative two-stage technology for biomass torrefaction generating high-quality biochar, more specifically biocoal, as solid fuel, and offering a promising solution to the challenges posed by the combustion of biomass. In particular, the higher quality of biochar as solid fuel reduces the build-up of unmanageable deposits on fired surfaces, as these deposits inhibit heat transfer and reduce the efficiency of biomass boilers. The proposed two-stage technology involves torrefaction in a hearth-type reactor at temperatures up to 250 °C, followed by a subsequent stage of cooling achieved through washing with water. The two-stage torrefaction technology is integrated within a vertical hearth reactor vessel composed of three superimposed trays serving for biomass input, torrefaction, and water washing combined with biomass cooling, respectively. Upon contact with torrefied biomass, cooling water turned into water vapor; hence, eliminating the requirement for subsequent biomass separation and drying. The system was tested on sunflower husk, and results showed a reduction in the content of problematic elements such as alkali metal chlorides or sulfur compounds in biochar ash, suggesting lower corrosion rates of convective heating surfaces of the boiler under ash sediments. It is hypothesized that, while water exited hot biomass in the form of water vapor instead of liquid water, as is typically the case in water-washing processes, a share of undesirable elements may still have been removed from biomass through vaporization, without necessitating any additional process for ash removal. Hence, the index values calculated according to the chemical analysis of biomass ash suggested that sunflower husk biochar (biocoal) resulting from the proposed two-stage torrefaction process may display fuel characteristics similar to biomasses whose combustion ash may form reduced levels of deposits on boiler surfaces. Therefore, the proposed technology holds the potential to improve solid fuel characteristics of biomass, targeting enhanced efficiency and sustainability of biomass-fired power plants.

Creating an Advanced Sensor Network to calculate real-time, mass-weighted flue gas composition and air heater leakage of a coal-fired utility boiler under dynamic operating conditions

Utilization of renewable energy sources to minimize the environmental impact of energy production has changed the way utility boilers operate, requiring frequent load cycling between full load and partial loads as low as 30%. Dynamic operation of coal-fired utility boilers significantly reduces boiler efficiency when compared to steady state at full load. Data-driven plant optimization has shown success with coal-fired utility boilers under dynamic operating conditions. The purpose of this work was to create an Advanced Sensor Network (ASN) to provide more extensive real-time data to inform dynamic plant optimization of Net Unit Heat Rate (NUHR). The ASN consists of gas sampling grids in the convective pass of the boiler and downstream of the air heater. These sampling grids allow for quantification of spatial variation of flue gas within the boiler and calculation of mass-weighted composition of flue gas through the combination of composition, velocity, and temperature measurements. The comparison of O2 between the inlet and outlet of the air heater is used to calculate air leakage in real time. Flue gas composition and air heater leakage are both important factors in boiler efficiency and NUHR.The results of this work support the value of mass-weighted averages for determining flue gas composition accurately. The measurements from the ASN show increased composition stratification during dynamic operation, with an average standard deviation 38% higher than observed during steady-state operation. Air heater leakage was also observed to increase from 2.8% to 5.1% following a load change. Prior to the installation of the ASN, these data would not have been available for dynamic control. These real-time data will be leveraged to calculate and optimize for NUHR during dynamic operation in future work.

Part load operation analysis of a biomass steam generator integrated with a Linear Fresnel solar field

Hybrid systems involving the use of biomass and solar energy have been proposed as a promising alternative to reduce greenhouse gas emissions and provide a way to overcome the inherited shortcomings of solar energy, such as intermittent and instability. Nevertheless, some plant components will operate in the off-design condition once solar energy is added to the cycle. In this regard, the objective of this work is to evaluate the performance of an existing biomass steam generator at partial loads, integrated with a Fresnel solar field in fuel-saving mode. The equipment consists of a biomass steam generator with a capacity to produce up to 50 t/h of superheated steam at 420 ℃/45 bar(a) to feed a cogeneration power plant. Measurement data were collected on-site to calculate the boiler efficiency at part loads according to the ASME PTC4 standard. The main components of the boiler were modeled using the OpenModelica® tool and the ThermoSysPro® library. The model accuracy was verified at different loads with the available measurement data and manufacturer datasheets. In conclusion, the implemented model allowed to reproduce the boiler performance in different loads, being able to evaluate the impact of the solar field integration and the hybrid boiler operation.

Revealing steam temperature characteristics for a double-reheat unit under coal calorific value variation

Currently, the severe fluctuation of steam temperature in double-reheat (DR) ultra-supercritical (USC) units has become a major problem that constrains their efficient and flexible operation, wherein the deviation of coal calorific value from the design value is one of the major reasons for this issue. However, the effect of coal calorific value variation on the steam temperature characteristics during the flexible operation of DR USC units remains unclear. A dynamic model of a 1000 MW DR USC unit is developed with primary principles and validated with real operation data. The effect of the coal calorific value variation on the steam temperature characteristics is revealed. Results show that as the calorific value of the coal increases, the main steam temperature can always maintain at the design value with attempering water adjustments, while the two reheat steam temperatures decrease. The steady-state deviations of the reheat steam temperatures are positively correlated with the magnitude of the coal calorific value variation, where the deviation of the secondary reheat steam temperature is larger. Meanwhile, as the load increases, the steady-state deviations of reheat steam temperatures increase, but the response time decreases. Finally, the effect of calorific value variation on the boiler efficiency is studied. As the coal calorific value increases, the boiler efficiency firstly rises caused by the decrease in the loss of the flue gas and then falls caused by the limited furnace temperature increase. This study provides guidance on the DR USC boiler operation under coal variation.

Multiobjective Optimization of the Energy Efficiency and the Steam Flow in a Bagasse Boiler

Renewable energy and energy efficiency are essential for a transition to cleaner and sustainable energy. Photovoltaic and wind turbine systems introduce operation, control, protection, and planning issues, particularly affecting frequency stability in the grid. In contrast to more widespread wind turbines and photovoltaic systems, biomass based electricity systems are more stable with no negative impacts on the grid stability. The efficiency of bagasse boilers is essential to guaranteeing adequate economic profit and environmental performance in sugar plants. To realize universal access to affordable, reliable, and modern energy services by 2030 (SDG 7), the use of renewable energy sources in energy mixing and energy efficiency must increase globally. Sugar plants include cogeneration systems to provide heat and electricity to the process and frequently sell an electricity surplus to the grid, which depends on their energy efficiency. Boilers are an essential component of cogeneration systems in sugar plants, and their efficiency is crucial to guarantee electricity surplus. Therefore, this study assessed a bagasse boiler to optimize its operational efficiency. To this end, the exergy assessment and multiobjective optimization based on a genetic algorithm are used. The results show that the exergy efficiency of the boiler improved by 0.8% with the optimization, reducing bagasse consumption by 23 t/d.

The combustion of torrefied biomass in commercial-scale domestic boilers

The use of solid renewable fuels in domestic-scale boilers, DSB is especially common in places where the distribution of other renewable energy sources is strongly limited (mountain and foothill regions). High moisture content and limited ventilation have a destructive impact on wood pellets' stability. Torrefaction of biomass is recognized as a possible way to enhance the wood pellets’ hardness under wet conditions. It was found that the maximal water uptake for torrefied biomass after its water immersion was only 18.7 wt%. In this work, the combustion performance and emission of main pollutants during the combustion of thermally–treated biomass are analyzed using two types of boilers: coal-fired 25 kWth (retort burner) and biomass-fired 10 kWth (pellets burner). The best results were obtained during the combustion of torrefied biomass in a 10 kWth DSB, i.e. emission of CO 218 g/GJ, SO2 2.5 g/GJ, NOx 111 g/GJ, and particulates 10.5 g/GJ, boiler efficiency of 90.23%. The combustion of torrefied biomass met the requirement of a 5th-class boiler according to the PN-EN 303-5 standard. Thermally–treated biomass can be used as a substitute fuel in DSB. Nevertheless, the boiler construction can be improved to obtain lower emissions of CO.

A Study on Modification of Boiler Chimney against Fouling to Enhance The Efficiency of Boiler

The boilers lose heat through various means, this statement refers to various ways in which heat is released or transferred, such as the emission of hot gases from chimneys, the disposal of hot wastewater, and the transmission of heat from heated surfaces. This study focuses on a chimney originally designed for a 15-ton/hour, 16-bar boiler. The issue with the chimney is that it experiences a high accumulation of carbon particles. In an effort to address the issue, the chimney has been re-engineered to minimize the build-up of scale which impacts the boiler's performance. It is specifically designed for use in boiler chimneys and features a hatch. The goal of this project is to decrease the size of the cross-sectional area of this particular section in order to enhance the flow of flue gases.

Kömür Yakıcılarında Yanma Verimi Tahmini için Gömülü Platformda Çalışabilen Evrişimsel Sinir Ağının Parametre Analizi

Accurately and effectively calculating combustion efficiency in coal burners is crucial for industrial boiler manufacturers. Two main approaches can be used to calculate boiler efficiency: 1) Analyzing the gas emitted from the flue; 2) Visualizing the combustion chamber in the boiler. Flue gas analyzers, which are not user-friendly, come with high costs. Additionally, the physical distance between the flue and the combustion chamber causes the measurement to be delayed. Methods based on visualizing the combustion chamber do not have these disadvantages. This study proposes a system based on visualizing the combustion chamber and has two contributions to the literature: 1) for the first time, the modern Convolutional Neural Networks (CNN) approach is used to estimate combustion efficiency; 2) the CNN architecture with optimal parameters can work on an embedded platform. When classical classification techniques and a CPU-supported processor card are used, efficiency can be calculated from one flame image in 1.7 seconds, while this number increases to approximately 20 frames per second (34 times faster) when the proposed CNN architecture and GPU-supported processor card are used. The results obtained demonstrate the superiority of the proposed CNN architecture and hardware over classical approaches in estimating coal boiler combustion efficiency.

Oxidative Potential of Metal-Containing Nanoparticles in Coal Fly Ash Generated from Coal-Fired Power Plants in China.

The overwhelming magnitude of coal-fired power plants has caused an inevitable release of metal-containing nanoparticles (MNPs) into the atmosphere, which may be inhaled into the respiratory system and cause oxidative stress. In this study, MNPs and oxidative potential (OP) were analyzed in <1 μm fractions of 56 coal fly ashes collected from Chinese CFPPs. The particle number concentrations (PNCs) of Fe- and Ti-containing NPs, as the dominant MNPs in CFAs, were in the range of 1.5 × 109 to 9.4 × 1010 and 6.4 × 108 to 4.1 × 1010 particles/mg, with average particle sizes of 87 and 89 nm, respectively. Average OP values of <1 μm fractions were 1.4-2.2 nmol AA min-1 μg-1 for three simulated lung fluids, which were 2-3 orders of magnitude higher than those of urban atmospheric PM2.5. According to structural equation model analysis, metal concentrations in <1 μm fractions, PNCs of Fe-/Ti-containing NPs, and their corresponding dissolved Fe/Ti (including NPs with minute sizes) can regulate OP of <1 μm fractions in CFAs. Elevated PNCs of MNPs in CFAs can be produced by CFPPs burning low-rank coals and with a low combustion efficiency boiler (e.g., circulating fluidized-bed boiler). Once entering lung fluids, they likely release more dissolved metals or tiny corresponding NPs, thus generating greater OP. This study provides the first comprehensive investigation of OP generated by MNPs in CFAs.

Techno-economic assessment of co-pyrolyzed kitchen waste and rice straw for co-generation of heat and power

Increasing concerns relating to depletion of fossil fuels and global warming coupled with significant growth in waste-to-energy markets have propelled the need for ingenious and flexible technologies that can effectively transform waste biomass into fuels and power at high efficiency. In this study, a comprehensive techno-economic investigation was undertaken to investigate the economic potential of utilizing co-pyrolyzed kitchen food waste and rice straw in a waste to heat and power facility based on microwave pyrolysis and a combined heat and power system. The study involved microwave pyrolysis experiments to investigate the effects of blending proportions of kitchen food waste and rice straw on the evolution of synthetic gas components based on gas chromatography analysis. The optimal blending proportion was then used to run the Aspen Plus heat and power plant simulation. Boiler efficiency, steam cycle thermal efficiency, electrical efficiency, and overall system efficiency were 96.30 %, 36.46 %, 41.61 %, and 35.11 %, respectively. The model had an estimated annual power production of 744,576 kWh/year, hot water production capacity of 1,727,649 L/year, and annual biochar production of 162,045 kg/year. A positive net present value was observed for the project after the second year, coupled with an internal rate of return of 0.62 and a profitability index of 3.85 over ten years. The heat generated can meet rapidly increasing urban heating needs and the power will contribute to grid stabilization. Sensitivity analysis revealed that the greatest potential performance improvements can be achieved by increasing biochar selling price and reducing total investment costs and total annual operating costs. Overall, the study shows scaled-up microwave-based heat and power technology to be a profitable and effective waste management and renewable energy solution.

Modification of perforated plate in fluidized-bed combustor chamber through computational fluid dynamics simulation

The combustion of solid fuels in a combustion chamber can be perfect if all the fuel included can burn out, and nothing remains. The combustion chamber requires sufficient air to burn all the fuel; therefore, meeting the air supply requires modifications with various considerations. The perforated plate modeled through computational fluid dynamics (CFD) was modified to investigate the excess air supply into the combustion chamber. The CFD simulation modeled in this study was used to validate the results of the experiments carried out with the previous fluidized-bed combustor technology. The simulation results show that the temperature increased for all fuels tested in geometry-2 compared with geometry-1. The best boiler efficiency from the simulation results is in geometry-1 for 45% oil palm midrib fuel with a mass flow rate of 7.78 kg/s. The maximum radiation was recorded from geometry-2 at a variation of 66.939 W/m2, with a heat loss level of 1.10 W/m2. Overall, the simulation was performed by modifying the fuel floor plate in geometry-2 to increase the temperature and radiation with lower heat loss.

Application of plasma burners for char combustion in a pulverized coal-fired (PC) boiler – Experimental and numerical analysis

This study considers the combustion of pulverized coal with unburned char recovered from ash of the industrial boiler. The concept of char combustion with coal is implemented by installing two plasma burners on the front wall of the combustion chamber. The main objective is to improve the boiler's efficiency by reducing the amount of unburned fuel. The behavior of the combustion process is investigated using CFD modeling of the combustion chamber with tangentially-fired burners and two plasma burners. Thermogravimetric analysis and laboratory-scale tests in a drop tube furnace are performed to obtain the combustion characteristics of the investigated char and, eventually, to assess the validity of co-firing with coal the unburned char. The CFD simulation of the non-retrofitted boiler with twelve pulverized-fired burners results in the excessive movement of coal particle streams toward the chamber walls outside of the designed swirl diameter caused by a high centrifugal force, thereby contributing to a decreased level of fuel burnout. The CFD results with plasma burners indicated that the swirl diameter is reduced improving the degree of mixing resulting in a more uniform temperature and velocity distributions. The average temperature at the combustion chamber outlet increases by approximately 40 °Creaching 1260 °C.

Energy efficiency of an electric boiler with indirect surface resistive heating of the heat carrier

Introduction. The share of energy for heating of households makes up to 80 % of the total energy consumption. Works on increase of energy efficiency of HVAC equipment make the biggest contribution to reduction of manmade impact on the environment. Power-to-Heat technology — electric boilers used for heating with water systems with radiators and low-temperature heating devices of the “warm floor” type. The research of energy efficiency of the wall mounted electric boiler equipped with the heat generator of indirect surface resistive heating of the heat carrier is presented.&#x0D; &#x0D; Materials and methods. The object of the research is an electric boiler ARDERIA E24, with a nominal capacity of 24 kWh, equipped with a circulation pump, an expansion tank with a volume of 6 L, a group of hydraulic safety and heat carrier recharge. Control of the capacity of the boiler is carried out on semistors with cooling radiators located on the reverse line of the circulation circuit. The boiler is equipped with an electric heat generator with indirect resistor surface heating of the heat carrier.&#x0D; &#x0D; Results. The studied electric heat generators have high specific volumetric power equal to 9.3 kWh/dm3. The average specific power of tubular electric heaters is 25.1 watts/cm2. The coefficient of energy efficiency of the boiler is 0.986. The hydraulic resistance of the unit is 1.25 meters of water column at a flow rate of 1.0 m3/h.&#x0D; &#x0D; Conclusions. The application of the electric heat generator design consisting of a cast aluminum block with tubular heating elements placed inside and a spiral coolant circulation pipe showed high energy efficiency with coefficients of 0.98–0.986 in the modulation range of heat output. The heat output modulation factor of the electric boiler is 12 (2–24 kW). The energy intensity of the heat generator design is 9.3 kWh/dm3, which is significantly higher than traditional heat generation units with “wet” heating elements. The boiler’s heat output control system eliminates the possibility of the temperature rising above 88 °C on the inner heating medium circulation pipe surface.

Techno-economic optimization of high-temperature heat pumps for waste heat recovery

Heat Pumps will play a crucial role in decarbonizing the heat supply, however, the progressive phase-out of environmentally impactful fluids and relevant cost of investments are today limiting the spread of power-to-heat technologies, especially for supply temperatures beyond 100 °C. This paper aims to carry out a comprehensive assessment, investigating the optimal design and most relevant features in different market scenarios. Since iso-butane (R600a) has demonstrated an interesting potential for such an application, it was selected for the purpose of this paper. First, the best heat pump sizing and the contribution of each component are discussed in detail from the techno-economic perspective, through optimization of both efficiency and cost of investment highlighting the greatest impact of evaporator. Eventually, a case study is considered to investigate the viability of replacing gas-fired boilers with HPs to supply heat up to 120 °C. Asensitivity analysis is performed highlighting that the large and centralized heat generationunitsworking almost continuously are generally more attractive. Moreover, this work establishes that when performing a sizing procedure or a sensitivity analysis, it is essential to account for the dependency of retail prices to the yearly energy consumption. The national trends of non-household retail prices are here provided for different countries. A market indicator is here defined, summarizing the market competitiveness of heat pumps vs boilers, combining the gas, and electricity cost, weighted on COP and boiler efficiency, in one single term. This indicator remained stable over the period 2017–2021, characterized by volatile energy market conditions, demonstrating the robustness of the economic conclusions of this paper. Sweden presents the best profitability (up to a net present value of 2.25 M€ for each MW of installed thermal capacity), France and Poland shows intermediate results (ca. 0.6 M€/MW), while in Italy and Germany, the worst markets, the minimum Heat Pump sizes to reach positive profits (ca 0.1 M€/MW) are respectively 1.5 MW and 4 MW.

Experimental Analysis of CFBC Boiler and AFBC Boiler with Different GCV, Boiler Loads and Excess Air

Abstract: The main motive of this study is to experimental analysis of the Atmospheric fluidized bed combustion boiler and Circulating fluidized bed combustion boiler with different gross calorific value of coal, boiler loads and excess air. For this analysis, use textile waste as a primary fuel and calculate GCV with help of bomb calorimeter. Conduct energy calculation of the overall plant and determine the efficiencies and energy losses of all the major components of the thermal power station. The study was carried out at Thermal power station of Industry Yarns at Mandideep and boiler section of thermal power plant is considered for the purpose of exergy analysis. The boiler of a power plant is the most effective section in eliminating exergy. Calculate the efficiency of CFBC and AFBC Boiler with different GCV of Textile waste and it is clearly shows that efficiency of CFBC boiler is higher than AFBC boiler in same GCV of textile waste. The present investigation show results of 30 mw power plant. Experiments were conducted using 0%, 20 %, 30% and 40% of excess air and 65%,70%,75%,80%,85%,90%,95% ,100% boiler loads. In the present investigation boiler house gives the best results at 0% excess air with maximum boiler load as far as the boiler efficiency (75.2%) are concerned. 65% boiler load With 0% excess air the boiler efficiency is found to be maximum (75.2%), which gives minimum heat loss. Without excess air AFBC boiler is not capable to burn low grade fuels show it is clear that for low grade fuel maximum efficiency of thermal power plant achieved by CFBC boiler because low grade fuel completely burns with 0% excess air.

Designing a Turning Guide Vane Using CFD for an Economizer of a Non-Furnace Boiler

Non-furnace boilers can improve the efficiency of industrial once-through boilers. However, temperature non-uniformity occurs in the economizer connected vertically to the boiler. Heat transfer performance is degraded by temperature non-uniformity. To solve this problem, a corbel was installed on the side wall of the economizer, and a baffle was installed on the transition duct. Consequently, although the thermal efficiency of the boiler was improved, significant temperature non-uniformity was still observed in the area upstream of the economizer. To address this issue, this study designed a turning guide vane (TGV) at the economizer inlet using computational fluid dynamics (CFD). First, CFD was performed for a case without a guide vane and a case with an existing baffle installed. By analyzing the streamlines obtained using CFD, two TGV designs were proposed. In the first design, guide vanes were installed along the desired streamline, and the concept of the existing TGV was followed. In the second design, an attempt was made to minimize the pressure drop by arranging guide vanes at the inlet. Both designs reduced the standard deviation of temperature by more than 30% and improved the volume goodness factor by 25%.

FEASIBILITY OF USING A HYDRO-CAVITATION MIXER IN AGRICULTURAL COMPLEXES

At present, the issue of using water-fuel emulsions in order to improve the technical, economic and environmental characteristics of various objects is becoming increasingly relevant in agro-industrial complexes. This is especially true in relation to fuel oils, which are used to obtain thermal energy of medium and low power, which takes place in agro-industrial complexes. As a rule, fuel oil contains moisture, solid fractions, has an increased flash point and other deviations from the norms that violate the combustion regime, contaminate the heating surface, increase fuel underburning, and form deposits of unburned coke particles along the gas path.&#x0D; A complex solution to these problems can be the creation of a uniformly distributed fine fraction of the moisture present in fuel oil and the destruction of quasi-crystalline structures that are part of fuel oil using various types of statutory devices, which, in order to obtain cavitation bubbles of optimal size in terms of technological impact, generate a cavity with a certain nature of unsteady motion in its tail section, which unfortunately leads to the destructive effect of cavitation erosion of hydraulic system elements.&#x0D; The solution to the problem was based on the principle of using the hydrodynamic parameters of moving liquids to form fine emulsions of fuel oils of various grades using a special design developed based on a cavitation generator, which ensures the removal of collapsing cavitation bubbles to the center of the flow, which significantly minimizes cavitation erosion of hydraulic system elements, hydro cavitation mixer.&#x0D; The developed scheme of the hydro-cavitation mixer provides the principle of processing fuel oils with a four-stage technology, which leads to the full combustion of the water-oil emulsion and the reduction of emissions of carcinogenic substances into the atmosphere, an increase in the efficiency of boilers by 2,4% and provides 25% -30% fuel oil savings. As a dispersed phase, not only water can be used, but also liquid fuel waste, industrial water, or mixtures thereof, which reduces the cost of their disposal.&#x0D; The developed hydro cavitation mixer is of particular interest for agro-industrial complexes, since it can be used for pasteurization of food products using the “cold boiling” phenomena, provided that the cavitation generator is made from the appropriate material.