Fire-tube Boiler Research Articles

Boiler efficiency with mixed methane fuel gas calculation

A boiler is a pressurized vessel utilized for the production of high-temperature steam. An often-encountered problem in boiler systems is the inefficiency of the working system, especially in fire tube boilers where heat loss occurs in the steam and fuel systems, leading to a decrease in efficiency. Hence, it is imperative to compute the efficiency of fire tube boilers in order to comply with efficiency regulations in operational procedures in the field. This study utilizes indirect methods to calculate efficiency. The calculation results indicate that the boiler efficiency, determined using the indirect method, is 80.4%. The calculated result satisfies the minimum requirement for boiler efficiency, which is between 70-90%.

Reproduction of decarburization caused by overheating in fire tube boiler material

One of the non-destructive testing methods for analysing fire tubes is the replica technique. This technique allows the investigation of microstructure, cracking, and high-temperature creep under operational circumstances without the cutting of the components. A cellulose-acetate foil was used to make a copy from the topography of the surface, which was suitable for microscopic analysis. In this paper, decarburization was generated in P355N fire tube material. The aim of the reproduction was to investigate the effect of overheating in boilers. The decarburization of the fire tube was made at different temperatures (300 – 900 °C) in an electric heating furnace. General deterioration and decarbonization began at 700 °C. A preliminary step of the decarburization was the transformation of the pearlite, which can be easily detected by scanning electron microscope. Grain growth could not be observed, and the particle size was unrelated to the thickness of the decarbonized layer.

Design and modifications of boiler mounting device in Asmara brewery factory

Energy and environment are closely related and important issues in the present all over world. Present industrial and others organization thought the unique of energy utilization and diverse source reviles such as coal, oil, gas, nuclear, hydropower, solar, wind and biofuel. The Non-renewable energy sources are being limited in this world and energy conservation is one of growing need nowadays. The major issues in the world’s energy consumption are getting used in boilers. Thus, this energy used has to be wisely consumed with great efficiency in industries. Boilers are considered as an important and an expensive property in many industries. In addition to initial cost, boilers have high operational and maintenance cost in order to secure production in safe and acceptable working conditions. In this study concerned with an energy saving, economic and environmental analysis of the fire tube boiler in ASMARA BREWERY. In this project, we concentrated on the improvement of boiler efficiency by recovering a portion of heat content of the flue gas. This is possible due to the most dominant device which is the economizer. The preexisting boiler was designed without an economizer. The present modification involved about the design of economizer in the boiler to reduce fuel consumption and thermal shock. Furthermore, in this type of boiler attain higher efficiency and little enhancement in the efficiency of the boiler will save an outsized amount of fuel and also help to reduce CO2 emission.

A Study on the Efficiency Improvement of Fire-tube Boiler Structure and Fuel

A Study on the Efficiency Improvement of Fire-tube Boiler Structure and Fuel

Evaluation of Boiler Feed Water Quality in Tofu Industry UD. FIT in Bocek Village

The UD FIT industry, situated in Bocek Village, Karangploso District, operates as a tofu factory employing modern equipment, including a fire tube boiler. The quality of feed water utilized in the boiler is essential for optimizing its efficiency. This study aimed to analyze the boiler feed water sourced from household wells at UD FIT's tofu factory, using various indicators such as turbidity, iron content, total dissolved solids (TDS), hardness, and pH levels. The test results revealed a temperature of 26°C, TDS of 253 mg/L, turbidity of 4.74 NTU, iron content of 1.123 mg/L, hardness of 180.5 mg/L, and pH of 7.89, with no detectable odor, color, or taste. Based on these findings, it is concluded that the boiler feed water utilized by UD FIT generally meet the quality standards, except for the pH parameter, which is not in accordance with the standard.

Heat Transfer and Thermal Efficiency in Oxy-Fuel Retrofit of 0.5 MW Fire Tube Gas Boiler

Industrial boilers cause significant energy wastage that could be mitigated with oxy-fuel combustion versus traditional air combustion. Despite several feasibility studies on oxy-fuel burners, they are widely avoided in industry due to major infrastructural challenges. This study measured the performance and heat transfer characteristics of each component in a 0.5 MW fire tube gas boiler after retrofitting it with an oxy-fuel burner. Comparisons were drawn across three combustion modes—air combustion, oxy-fuel combustion, and oxy-fuel flue gas recirculation (FGR). The Dittus–Boelter equation was employed to predict heat transfer in the fire tube for all combustion modes at full load (100%). Heat transfer in the latent heat section of the economizer was measured and compared with predictions using the Zukauskas equation. With this retrofit, oxy-fuel combustion improved the thermal efficiency by about 3–4%. In oxy-fuel combustion, the flow rate of exhaust gas decreased. When integrated into an existing fire tube boiler, the fire tube’s heat transfer contribution diminished greatly, suggesting the economic viability of a redesigned, reduced fire tube section. Additionally, a new design could address the notable increase in gas radiation from the fire tube in oxy-fuel and FGR, as well as aid in the efficient recovery of condensation heat from exhaust gases.

Effect of feed water temperature on the performance and economics of thermal energy driven multiple effect distillation system for water treatment

This study presents the design, fabrication, and experimental analysis of Multiple Effect Distillation (MED) plant with four effects (4+C system). A total of 15 experiments were conducted, systematically categorized based on feed water temperature. Baby fire tube boiler producing 25 kg/h steam were installed with plant for experimental study. The investigation focused on distillate output, Gain Output Ratio, Overall Heat Transfer Coefficient, and the cost of distillate. Investigation demonstrates a notable increase in distillate output and Gain Output Ratio as the feed water temperature increases. Furthermore, improvements in the Overall Heat Transfer Coefficient with higher temperatures was observed. Notably, the cost of distillate decreased from $2.5/m³ to $1.5/m³ as the temperature increased. Findings suggest that 80 °C feed water temperature optimizes distillate output and Gain Output Ratio. Beyond this temperature, a decrease in distillate production occurs due to reduced latent heat of vaporization. The economic analysis reveals a trade-off between distillate output and cost, emphasizing the importance of optimizing feed water temperature. The inlet temperature was maintained at 115 ± 0.3 °C, while the boiler pressure remained at 5 bar. In the pilot plant configuration, MED system operating at 80 °C generated a daily water output of 438.93 L/day. The associated cost for producing fresh water was1.65 $/m3, and the system achieved a maximum Gain output ratio of 1.95.

High Temperature Biomass Fired Stirling Engine (HTBS)

Biomass is an important resource for the utilisation of renewable energy not only in Germany, but in many other countries. Being sufficient to provide base load it is capable to stabilise electricity grids besides contributing to climate change precaution. Additionally it is essential that the applications for heat, power and fuel feature high conversion efficiencies. There fore the on-site generation of electricity is a crucial contribution to renewable energy supply, especially in real small-scale applications. The project “HTBioStir” - development of a high temperature heat exchanger for the coupling of biomass boiler and Stirling engine - is designed and realized as a fundamental research project focusing on important mechanisms of heat transfer. The basic approach to generate electricity and heat implies the transfer of enthalpy on high temperature levels from the flue gases of a wood chip operated fire tube boiler to the working fluid helium through the heater head of a Stirling engine generator set. Using an indirect heat transfer mechanism, air as the carrier, an innovative heat exchanger with surface structured industrial power tube bundle and upstream a similar recuperative air-preheater by which an α-type SOLO 2V is operated to gene rate electricity. The leaving air at a much lower temperature level serves then as preheated oxidant in the furnace, while the flue gases produce hot water in the boiler. At present measure ment campaigns were carried out to establish energy and mass balances of the fire tube boiler as well as the Stirling engine.

Simplified Applicable Model for Fire Tube Boiler

Simplified Applicable Model for Fire Tube Boiler

Emissions and energy/exergy efficiency in an industrial boiler with biodiesel and other fuels

Industrial boilers are significant equipment in industrial operations used to provide steam or heat for production. More than 80% of fire-tube boilers use heavy oil in small and middle industries in Taiwan. Due to biodiesel as a sustainable fuel, the objective of this study is to measure experimentally and evaluated energy and exergy analysis of the fire-tube boiler using biodiesel (BD), undistilled biodiesel (UB), low sulfur oil (LSO), and ultra-low sulfur diesel (ULSD), and the various mixing ratios of undistilled biodiesel and low sulfur oil (UB90, UB70, and UB50) to reduce emissions from fire-tube boilers. Results from BD and UB are comparable, and UB exhibited a high NOx reduction rate of 68.9% and a high SO2 reduction rate of 99.5% compared to LSO. The boiler that employed UB decreased CO2 emissions, NOx, and SO2 emissions. NOx emission increases with increasing LSO content. The boiler’s maximum energy efficiency when using BD is 86.6%, and the overall exergy efficiency is 44.8%. The boiler with UB70 had the lowest energy efficiency of 73.5% and the lowest exergy efficiency of 38.7% because of the increased heat loss. The Benefits of this study are not only for boiler applications but also for government policy references.

Simplified finite volume-based dynamic modeling, experimental validation, and data-driven simulation of a fire-tube hot-water boiler

This paper proposes and implements a novel approach to simulate the dynamic behavior of hot-water fire-tube boilers, in which physical phenomena-based and data-driven modeling methodologies have both been employed. The first model, which includes a reduced one-dimensional finite volume method to simulate the flue-gas side’s behavior, can be employed for accurate sizing of the unit considering end-users’ dynamic consumption profile. In the data-driven model instead, machine learning algorithms are used to estimate hot water’s supply temperature, which makes it a suitable tool for real-time prediction and model predictive control. Utilizing the latter model in combination with an advanced management system allows reducing the plant’s energy consumption and enhancing its controllability. Employing the measurements performed in an Italian industrial firm, the developed model is validated and is demonstrated to have a limited thermal efficiency estimation bias of 1.2%. Furthermore, the data-driven model achieves a mean absolute relative difference error lower than 6%, demonstrating its acceptable accuracy for various prediction horizons.

CALCULATION OF HEAT TRANSFER INTENSITY OF GAS FUEL COMBUSTION PRODUCTS

Link for citation: Mrakin A.N., Afanaseva O.V., Kuleshov O.Yu. Calculation of heat transfer intensity of gas fuel combustion products. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 5, рр.109-115. The relevance of the research is determined by the modern trend in the field of thermal power engineering and heat engineering for the transition from traditional gaseous fuel (methane) to the use of hydrogen, methane-hydrogen mixtures, as well as thermochemical conversion gases. Switching to new non-design fuel is justified by considerations of reducing the negative impact on the environment and increasing the thermal efficiency of fuel combustion plants. In this case, the use of fuels with a composition different from the design one will affect the heat transfer processes. The main aim: carrying out a comparative analysis of indicators of the intensity of radiant and convective heat transfer of combustion products of non-design fuels, such as hydrogen, methane-hydrogen mixture and thermochemical conversion gases. As an assumption in the formulation of the problem and objectives of the study, the constancy of the heat release power in the apparatus due to changes in the amount of fuel burned was taken. Objects: heat exchange surface of a fire-tube hot water boiler. Methods: carrying out numerical calculation using traditional approaches to determine the indicators of the intensity of heat transfer in the system «combustion products – metal wall of the pipe of thermal power plants». We also used the relations tested earlier by other authors to calculate the thermophysical parameters of gas mixtures. Results. According to the results of the performed comparative calculations, we can conclude that the transition from the use of conventional fuel (natural gas/methane) to its thermochemical conversion gases under the considered conditions has almost no effect on the integral heat transfer performance. To a greater extent, this transition is caused by changes in the intensity of heat transfer for products of combustion of hydrogen and methane-hydrogen mixture, which will affect the operation of thermal power and heat technological installations. At the same time, it is necessary to conduct additional research on the combustion kinetics of thermochemical methane conversion gases, their thermophysical properties, etc., because the hardware design, type of the catalyst used and operating parameters of the process will affect the composition of obtained synthesis gas.

Review on Performance Analysis of Fire Tube Boilers

Review on Performance Analysis of Fire Tube Boilers

ВЛИЯНИЕ ГЕОМЕТРИЧЕСКИХ ХАРАКТЕРИСТИК ПРОВОЛОЧНЫХ СПИРАЛЬНЫХ ВСТАВОК НА КОЭФФИЦИЕНТ ТЕПЛООТДАЧИ ПРОДУКТОВ СГОРАНИЯ В ДЫМОГАРНЫХ ТРУБКАХ КОТЛА

The article considers the influence of the geometric characteristics of a wire spiral turbulator on the heat transfer coefficient of combustion products. The design and operation principle of a fire-tube boiler are described. A technique for thermal calculation of a fire-tube boiler and a model for calculating the heat transfer coefficient when using a turbulator are presented. A computational experiment has been carried out and a comparative analysis of the change in the heat transfer coefficient of combustion products depending on various geometric characteristics of a wire spiral turbulator has been carried out. The maximum increase in the heat transfer coefficient by 58 % was recorded with an increase in the angle of inclination of the turns of the turbulator from 30° to 80°

Experimental model validation and predictive control strategy for an industrial fire-tube boiler

This paper presents a flexible control structure for fire-tube boilers based on a suitable integration of the typical decentralized PI control structure and model predictive control technique. First, a dynamic nonlinear reference model of the fire-tube boilers is developed combining models available in the technical literature, based on first principle laws. The overall system model is considered as a gray-box model, and it has been validated with real data. Then, a suitable control-oriented model is derived out of the nonlinear reference model, in order to design a hybrid cascade MPC-PI control structure capable of guaranteeing stability, improving performances and enforcing real-time constraints. The flexibility of such a structure can be exploited to impose different types of functional behavior to the boiler itself, from the performance-related ones to the efficiency increase ones. While the reference non-linear model is large and detailed, the control-oriented one is simplified so that a few process parameters are identified to reduce dramatically the implementation in the MPC controller hardware and software framework. A sensitivity analysis with respect to these process parameters highlights the robustness and easy implementation of such a strategy. Two MPC configurations have been developed and tested in simulation over the validated boiler model. Then, a customized algorithm has been developed to understand a massive quantization phenomenon on the boiler pressure measurement. Finally, a test session conducted on a real fire-tube boiler quantifies the performance benefits of one configuration of the MPC-PI control structure with respect to the PI control. • Tuning of a dynamic nonlinear reference model of the fire-tube boilers with real data. • A hybrid cascade MPC-decentralized PID control structure, easly tunable. • Sensitivity analysis to test the robustness and easy implementation of such a control strategy. • A customized algorithm to reject a massive quantization on the boiler pressure measurement. • Implementation of the optimal control strategy and test session on a real fire-tube boiler.

Performance enhancement of an industrial fire tube boiler

An Industrial boiler is considered as highly energy intensive equipment. The primary objective of this study is to identify and quantify the potential losses of different energy sections of the fire tube boiler and its overall performance. Several energy saving measures such as combustion optimization, excess air control, control of flue gases temperature and effect of excessive or uncontrolled steam blow down optimization, on the overall performance of boiler are also applied. Energy as a result of energy saving measure has been determined as well. In present study, some main causes of energy wastages are summed up, by using a Energy Auditing. From the results of energy audit, the boiler’s thermal energy efficiency and combustion efficiency are found to be 70.09% and 75.7% respectively. It was also observed that these losses can be reduced by controlling stack temperature, excess air and optimized blow down. There covered energy can be utilized to preheat the combustion air and feed water. Economic evaluation of energy saving measure resulted in annual fuel saving of 6.3 Million PKRs without any investment but only improving working methodologies. As a result of these efforts, the savings in terms of cost has also been determined.

Implementation of a multi-setpoint strategy for fire-tube boilers utilized in food and beverage industry: Estimating the fuel saving potential

The present work aims at estimating the fuel saving potential of implementing a multi-setpoint control strategy for a fire-tube boiler that addresses a steam demand with a notable (daily) variation in the requested pressure level. The daily steam consumption profile of an Italian cheese factory is accordingly considered as the case study. Next, a dynamic PID controller is developed and tuned, aiming at enhancing the boiler’s controllability at partial load conditions (in comparison with a traditional PID controller). In the next step, a multi-setpoint strategy is implemented, in which the pressure setpoint (following the desired pressure profile) is dynamically modified. The yearly fuel consumption of the boiler is then determined and is compared with the consumed fuel while employing the currently utilized constant-setpoint approach. The obtained results demonstrate that employing the proposed strategy results in reducing the yearly fuel consumption by 4.5%. The approach that is proposed in the present study can be employed by many steam end-users in the food and beverage industry, specifically in Italy, whose needed pressure level is highly variable.

Failure Mode and Effect Analysis of Fire Tube Boilers Under Specific Operative Conditions

Failure Mode and Effect Analysis of Fire Tube Boilers Under Specific Operative Conditions

Water regime of fire-tube boilers

The active development of autonomous heat supply over the past 25 years has led to the widespread use of low-power hot water boilers up to 2.5 MW. Rational use in the design of autonomous sources of heat supply of the design features of hot water boilers significantly improves their technical, economic and operational performance. The paper considers and analyzes a number of design features, modes of operation and operation of low-power hot water boilers, which significantly affect the efficiency and reliability of their use.

ANALISIS EFISIENSI ENERGI PADA BOILER INDUSTRI TIPE FIRE-TUBE KAPASITAS 2TON/JAM DENGAN BAHAN BAKAR COMPRESSED NATURAL GAS (CNG) DI PT.X

ABSTRACT
 Boiler is a high pressure vessel or tank that functions to produce hot steam. Problems that often occur in the field on boiler machines are not efficient well when the work system or operating process in the field, especially when the process is under operating conditions on a fire tube boiler engine always experiences heat loss in the steam or steam system and the fuel system which affects the efficiency of the engine. fire tube boilers are not optimal for steam output. Therefore, with these conditions, it is necessary to calculate the efficiency of a good fire tube type boiler engine in order to meet the appropriate efficiency value standards in the operating process in the field. The method used in this study is the calculation of efficiency carried out by two methods, namely the direct method and the indirect method. Based on the results of efficiency calculations using the direct method, the efficiency value is 81.04%, while the results of calculations using the indirect method are 85.65%. The results of the calculation of efficiency values ​​that have been carried out from two methods, namely the direct and indirect methods meet the standard efficiency value of the boiler engine ≥ 80 %.
 
 Keywords: Fire Tube Boiler, Efficiency, Heat Loss, Direct and Indirect Method