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Fixed Bed Combustion
Published in Kenneth M. Bryden, Kenneth W. Ragland, Song-Charng Kong, Combustion Engineering, 2022
Kenneth M. Bryden, Kenneth W. Ragland, Song-Charng Kong
Boiler efficiency is defined (see also Chapter 6) as the useful heat output divided by the energy input. Referring to Figure 15.6, ηb=qm˙fHHV+W˙aux where W˙aux is the auxiliary power to run the fans, pumps, and feeder. If the fuel flow rate is known, then the furnace efficiency can be determined directly from Equation (15.2). Frequently the fuel flow rate is not measured, and for this situation the indirect method given by Equation (6.9) may be used. The indirect method is also useful for investigating how to improve the efficiency. In Chapter 6, we noted that the boiler efficiency is increased by reducing the excess air, reducing the extraneous heat loss, and reducing the exhaust (stack) temperature. The excess air should be reduced to the point where the CO, combustibles in the fly ash, and stack opacity just begin to increase. Radiation heat loss from the walls of the boiler is generally less than 1% for large boilers.
Boiler Plant Operations
Published in Carl Bozzuto, Boiler Operator's Handbook, 2021
Testing of safety valves and inspection of the boilers by inspectors are essential in reducing exposure to a boiler failure. Back before the boiler and pressure vessel codes were instituted, the conditions that existed led to millions of injuries and thousands of deaths from boiler failures. It is the benefit of a third party inspection (with no responsibility to the owner of the boiler) that makes the system as good as it is. Every boiler inspector is well trained and tested before receiving a commission as a National Board Inspector. Take advantage of their training and skills during every inspection, calling their attention to changes or conditions that are questionable. Never try to hide things from them. Remember, the operator is likely to be closest to that boiler if it does explode.
Steam and Condensate Systems
Published in Stephen A. Roosa, Steve Doty, Wayne C. Turner, Energy Management Handbook, 2020
Boiler efficiency. The boiler efficiency is the percentage of energy released in the burning of fuel in a boiler that is used to produce steam. The remaining percentage is lost through radiation from the boiler surfaces, blowdown of the boiler water to maintain satisfactory impurity levels, and loss of the hot flue gases in the stack. While this chapter considers boiler efficiency, which is also discussed in Chapter 5, it is important to recognize that this parameter relates the energy savings obtainable by conserving steam to the fuel savings obtainable at the boiler, a relation of economic importance. Thus, if we save 100 Btu of steam energy and have a boiler with an efficiency of 80%, the actual fuel energy saved would be 100 Btu/0.80 or 125 Btu. Because boilers always have an efficiency of less than 100% (more commonly from 75% to 80%) there is a built-in amplifier on any energy savings effected in the steam system.
Emission factors of industrial boilers burning biomass-derived fuels
Published in Journal of the Air & Waste Management Association, 2023
Arpit Bhatt, Vikram Ravi, Yimin Zhang, Garvin Heath, Ryan Davis, Eric C.D. Tan
Factors affecting the types and magnitudes of emissions from the boiler include fuel type (e.g., gas, biomass, coal, or a mixture), type of boiler (fluidized bed, stoker, etc.), fuel properties (such as sulfur, nitrogen, ash, and moisture content), and firing practices employed by the facility. For example, a biorefinery that utilizes biomass as a feedstock may pretreat the feedstock using sulfuric acid and ammonia to break down the cellulose for further processing (Davis et al. 2022), resulting in much higher levels of nitrogen and sulfuric acid in the boiler fuel downstream than the typical woody biomass. The emission factors of combusting biomass could be considerably different than those of combusting solid fossil fuels such as coal. This is due to biomass’ higher heterogeneous particle size, higher volatility, higher moisture content and oxygen level, and lower sulfur content and energy density. Moreover, the transport-limited devolatilization characteristics of biomass particles could affect carbon conversion, heat release, pollutant generation, ash formation (from silicon, potassium, etc.), and deposition, among others (Panagiotis 2010).
Quasi-oppositional JAYA optimized 2-degree-of-freedom PID controller for load-frequency control of interconnected power systems
Published in International Journal of Modelling and Simulation, 2022
Dipayan Guha, Provas Kumar Roy, Subrata Banerjee
To show the efficacy of proposed QOJAYA: 2DOF-PID control algorithm, the dynamic performance of test system has been assessed considering nonlinearities like GDB, BD, and time-delay. The GDB is defined as a total magnitude of sustained speed change within which there is no resulting change in the governor valve position. The backlash type of nonlinearity is used to represent the GDB, and its maximum value is limited to 0.06% (i.e., 0.036 sec) [49]. A boiler is a device meant for producing steam under pressure. To meet the generation with load demand, the turbine valves are controlled through immediate control action imposed by the boiler by sensing the change in steam flow and the drum pressure. The schematic diagram of a drum-type boiler is shown in [50], which involves a considerable time delay in the fuel system. Pade approximation and signal flow methods are used to determine the transfer function model of BD [33]. Owing to the expansion of physical systems, restructuring, and complexities involved in the power system, the LFC study considering time-delay is essential. The signal processing and data exchanging operation produce a considerable delay in the LFC system. Mathematically, the rationalized from of time-delay (TD), by using Pade 2nd-order approximation, can be expressed as [33]
Study on the use of fabric wastes as an energy source for boiler by incineration process
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Boiler is a fuel-burning apparatus for heating water. The heated or vaporized water exits the boiler for use in various processes such as ironing, dyeing, dyeing finishing etc. For running a boiler, we need water, fuel and electricity. Depending on the nature of fuel there are different types of boiler such as gas boiler, diesel boiler, jhut boiler, EGB boiler, electric boiler etc. In this segment, author will analyze total cost and consumption of different nonrenewable energies and how jhut boiler could act as an alternative considering different issues.