Papers by Keyword: Flue Gas

Abstract: The present research targeted the measurement of flue gas flow rates in industrial boiler applications, to improve boiler efficiency in Sri Lanka. This study discussed three methodologies for flow measurement and placed significant emphasis on the benefits of thermal mass flow meters, given their accuracy and reliability, especially within low flow rates. A thorough literature review was conducted to pinpoint critical parameters involved in the generation of boiler performance: flue gas composition and draft regulation. This research spotlights the deficiency in the current measurement practices, hence, a systematic approach to develop, a cost-effective and regionally adaptable solution is presented for the flue gas flow measurement. The investigation validates the proposed measurement techniques by using a combination of theoretical analysis and CFD simulations and demonstrates that the simulated flow rates are close to calculated values, with minimum differences of 0.000461 kg/s. results imply that the optimization of flue gas flow measurement can result in significant enhancements in combustion efficiency. The research ultimately contributes to the betterment of boiler operation practices in Sri Lanka by providing recommendations for future studies and practical implementations to enhance resource management and environmental sustainability within the industrial sector.

Abstract: As the energy crisis's impact spreads, energy consumption has emerged as the fundamental impediment to industry's long-term viability. Utilizing and recovering various sources of waste heat can considerably reduce an organization's energy use. Energy conservation is crucial not just for fuel use, but also for the conservation and protection of the global ecosystem. As a result, it is necessary to make a concerted effort to save energy generated by waste heat. This paper aims to develop flue gas as a substitute for wood burning for drying mold at foundry shop of G-7 trading and industrial PLC. Flue gas temperature and velocity were measured at various locations throughout this study, and an analytical computation was done on the flue gas supply system and mold drying chamber. To show what happens within the hot flue gas supply duct and mould drying chamber, Computational Fluid Dynamics (CFD) Ansys software was used. The business benefits by eliminating the usage of wood as a fuel and making the process more cost-effective and environmentally friendly by capturing hot flue gas from the top section of the furnace or chimney and supplying it through duct to the drying chamber to dry the mold. As a result, the negative impact of deforestation will be mitigated, and a favorable working environment will be established.

Abstract: This paper presents the optimal design of vent pipe in a fire station by using design of experiments and analytical method of heat transfer theory. In order to calculate formulation without using tables, equations in terms of temperature are developed for five air properties such as specific heat, thermal conductivity, kinematic viscosity, density and Prandtl number. It is shown that the equations accurately approximate the variations of air properties in terms of temperature. Series of design analysis are performed under considering the process parameters such as inlet temperature, pipe diameter and heat transfer rate. Orthogonal arrays of L₂₇ are used. The signal-to-noise (S/N) and analysis of variance (ANOVA) are utilized to determine the effect of parameters on objective functions, surface temperature and outlet temperature. From the results it is clear that inlet temperature is prominent on objective function.

Abstract: Energy conservation is a major topic of concern since our energy sources are exhausting exponentially. This paper focuses on waste heat recovery using which scrap preheating is done in metal castings using sand molds. During solidification of molten metal, most of the heat is lost to the sand. The proposal is to prepare the sand mould with aluminium shots surrounding the mold cavity. These shots absorb some of the heat from the solidifying metal in the mold cavity. The heated shots are separated from the mold and they are allowed to transfer their heat energy to the metal scrap by conduction. The experiments indicate that at least 6.4% of heat recovery is achievable. This will be instrumental in reducing the enormous amount of energy spent to melt the metal considering the fact that casting is the most widely used manufacturing process globally.

Abstract: Air pre-heater and economizer are heat transfer surfaces in which air temperature and water temperature are raised by transferring heat from other media such as flue gas. Hot air is necessary for rapid combustion in the furnace and also for drying coal in milling plants. So an essential boiler accessory which serves this purpose is air pre-heater. The air pre-heater is not essential for operation of steam generator, but they are used where a study of cost indicates that money can be saved or efficient combustion can be obtained by their use. The decision for its adoption can be made when the financial advantages is weighed against the capital cost of heater. The efficiency of the boiler increases with the increase in the temperature of the combustion air used in the furnace. This is achieved by the increased temperature of the flue gas in the air preheater and economizer zone. This paper deals with the different ways to obtain the maximum heat from the flue gas travelling through the air preheater and the economizer zone to improve the boiler efficiency.

Abstract: Mercury is one of harmful pollutants during the coal-burning process that can not be ignored. The Ontario-Hydro method, Method 30B and Method 29 are mainly used for sampling the mercury in the flue gas from the coal-fired industrial boilers. This article studied the control ability of the mercury by the electrostatic precipitator (ESP), wet flue gas device (WFGD) and the dust removal and desulfurization integration at home and abroad.

Abstract: In this paper, a new system which absorbs the water vapor in flue gas of natural gas fired boiler (NGFB) by desiccant solution is introduced. This system can recover the latent heat of water vapor and improve the thermal efficiency of the NGFB significantly. In the theoretical analysis, the packed tower which is the most important equipment of solution circulation heat recovery system (SCHRS) can be designed by establishing a mathematical model. Based on the recovery efficiency of water vapor by desiccant solution absorption, the thermal efficiency analysis of NGFB is discussed, which show that SCHRS has a good application prospect in NGFB waste heat recovery.

Abstract: The revamping project of turning coal-burning boiler into gas-fired boiler for urban heat supply in Tianjin causes high vapor content in flue gas, which has great influences on the day lighting of surrounding buildings. In this paper, CFD software is introduced to simulate the distributions of NO_x, SO₂ and vapor in space after leaving the chimney and their impacts on surrounding buildings with the effect of the atmosphere. Result shows that flue gas discharged from the chimney with the height of 30 m has significant impacts on the surrounding buildings.

Abstract: Flue gas of boiler is a kind of great potential waste heat resource. Relatively high temperature of exhaust has caused a vast waste of energy and serious environmental thermal pollutions. To make a full and reasonable use of the heat resource, a simplified single-tube heat exchanger is introduced in this paper. Dry air and wet air with different temperatures transfer heat with flue gas in the same model. And the results show that heat near the inner wall exchanges more violently than any other space in the heater. For dry air, the higher temperature of the air enters into the heater, the lower heat transfer effect of the heater. Heat exchange effect of the wet air with 0.03 mole fraction of water is more higher than that of dry air in this model.

Abstract: Currently, climate change and global warming are the main issues on environmental concern due to the higher amount of carbon dioxide in the atmosphere. The main sources of carbon dioxide are energy-related activities such as power generation. Now, the effective technology to remove CO₂ from these sources is absorption especially with amine solution. The commercially used amine solutions are monoethanolamine (MEA) and methyldiethanolamine (MDEA). Nevertheless, they also have disadvantages such as low capacity, corrosion and high energy requirement. Therefore, many new solvents have been developed to improve efficiency for CO₂ capture. Therefore, the objective of this work is to measure the vapor-liquid equilibrium of CO₂ in a 5M aqueous solution of 2-(Diethylamino) ethanol (DEAE) as a novel solution at the temperature from 30 °C to 80 °C and CO₂ partial pressures ranging from 5 to 100 kPa. The solubility results of CO₂ in DEAE solution are compared with those of aqueous solution of MEA. For cyclic capacity, the results present that DEAE provides higher performance which is up to 861% higher than that of MEA. This means that DEAE can save more energy and cost for solution regeneration.