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Biofilm Monitoring and On-line Control: 20-Month Experience in Seawater
Published in A. K. Tiller, C. A. C. Sequeira, Microbial Corrosion, 2021
G. Salvago, G. Fumagalli, P. Cristiani, G. Rocchinp
It is well-known that biofilms develop on metallic surfaces in contact with water and that this is one of the factors responsible for corrosion of metals and alloys. In the case of heat exchange equipment cooled with seawater biofouling as well as corrosion, will increase the resistance to heat transfer and lead to a decrease in efficiency. For thermal power plants, for instance, the decrease of the thermal efficiency increases the specific consumption of fuel so that costs for electric energy production increase [1, 2].
Vapor and Advanced Power Cycles
Published in Kavati Venkateswarlu, Engineering Thermodynamics, 2020
Electric power generation in the world largely depends on thermal power; thus it is essential to improve the thermal efficiency of steam power plants. A small increase in thermal efficiency can cause a large fuel savings and reduction in greenhouse gas emissions. Generally thermal efficiency of a heat engine cycle can be increased by either raising the temperature at which heat is added (considering the metallurgical limits) or lowering the temperature at which heat is rejected. The least possible temperature of the heat rejection is the temperature of surroundings.
Bare Necessities
Published in S. Can Gülen, Gas Turbine Combined Cycle Power Plants, 2019
In performance analysis, the primary goal is calculating net electric power output and thermal efficiency (or, equivalently, heat rate or HR) of the GTCC power plant at design and off-design conditions. The former is obvious; it is the raison d’être of the book you are reading. Thermal efficiency is the ratio of power output (net or gross, see below) to heat (fuel) consumption. Its importance cannot be overstated due to its impact on Conservation of limited fuel resourcesMinimization of operating costsReduction of criteria pollutants and CO2 emissions.
Performance comparison study on differently configured solar photovoltaic thermal water collector systems
Published in International Journal of Ambient Energy, 2022
Ratio between output thermal power and input power is defined as thermal efficiency. Table 9 presents the periodic variations in the ηT obtained from the system during 8 consecutive days of experiments. Average ηT observed during 8 continuous days of experimentation varies between a minimum of 5.90% (±0.267%) in CASE-C and maximum of 20.23% (±0.267%) in (CASE-G). The orders of ηT delivered by all the eight systems tested under this study are as follows: CASE-A is primarily designed only for the generation of the electrical power. Also, there is no provision or a principal component to convert principle solar energy into the electrical energy. Thus, the CASE-A is not listed in the above order of ηT.
An evaluation of alternative fuels’ spray penetration at various spray cone angles and injection pressures using a simple evaporation model
Published in Biofuels, 2022
Joanne Lim, N.A. Razak, Nurul Musfirah Mazlan
Despite alternative fuels, the combustion process can be optimised to improve thermal efficiency and reduce gas emissions at the same time. This process involves improving spray quality, which can be measured through spray penetration, spray evaporation and droplet size distribution. Spray penetration is the maximum distance the spray can reach when injected into stagnant or crossflowing air. The penetration is influenced by the kinetic energy of the initial liquid jet and the aerodynamic resistance of the surrounding gas [17]. Spray evaporation involves heat and mass transfer between the drop surface and the surrounding hot gas through conduction and convection. Many factors influence the overall rate of evaporation, such as the pressure and temperature of the gas, droplet temperature and volatility, and the size and velocity of the droplets [17].
Mitigation of harmful exhaust pollutants of DI diesel engine using emulsified fuel and hythane gas in a dual-fuel mode
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Radha Krishna Gopidesi, Premkartikkumar Sr, Vallapudi Dhana Raju
It is defined as the amount of power generated concerning the heat supplied to the engine. It is the sign for the conversion of chemical energy into the amount of useful power generation. Thermal efficiency essentially relies upon the heating value of fuel and the effective mass of fuel utilization in the combustion process. The BTE of the pure diesel and the emulsion samples of WiDE5, WiDE10, and WiDE15 are obtained as follows: at rated load these are 28.54%, 25.71%, 26.49%, and 26.02%, respectively. Figure 4 shows the entire BTE of fuel samples related to BP. Diesel operation showed a higher BTE than all WiDE samples. But WiDE10 showed slightly higher BTE than the WiDE5 with the effect of an increase in droplet life. The reason behind the lower BTE for the WiDE is the poor air-fuel mixture formation and prior injection timing with the effect of the higher viscosity and density of WiDE. The fuel burning characteristics are highly influenced by the Cetane number of fuel. Higher Cetane number of fuel results in higher efficiency and smoother combustion. The viscosity and density increased by an increment in the water quantity in the emulsion reported by Nanthagopal and Subbarao (2009).