Research of Exhaust Gas Boiler Heat Exchange Surfaces with Reduced Corrosion When Water-Fuel Emulsion Combustion

Abstract

The application of water-fuel emulsion (WFE) in internal combustion engines enables to reduce the consumption of sulfurous fuel oils, thereby protecting the environment from emissions of sulfur and nitrogen oxides, as well revealing a great potential for the heat utilization of exhaust gases. The efficiency of utilization of exhaust gas heat in exhaust boilers (EGB) depends on their temperature at the outlet of EGB, id est. the depth of heat utilization. Exhaust gas temperature is limited by the rate of low-temperature corrosion (LTC), which reaches a level of 1.2 mm/year at the wall temperature of about 110 °C for the condensing heat exchange surfaces (HES) and reduces the reliability of the HES operation. Therefore, decreasing the corrosion rate of condensing HES at wall temperature below 110 °C to an acceptable level (about 0.2 mm/year) when undergoing WFE combustion will make it possible to reduce the exhaust gas temperature and, consequently, increase the efficiency of EGB and fuel saving during the operation of the ship power plant. The aim of the research is to assess improvements to the reliability, durability and efficient operation of condensing HES in marine EGB undergoing WFE combustion in a diesel engine based on experimental studies of the LTC process. A special experimental setup was developed for investigation. The use of WFE with a decreased wall temperature of HES below 80 to 70 °C would improve the reliability of the EGB along the accepted service life, increase the lifetime of the HES metal by almost six times as well as the overhaul period, and reduce the cost of repairing condensing HES. Furthermore, due to the reducing corrosion rate under WFE combustion, the application of low-temperature condensing HES makes it possible to enhance the efficiency of deeper exhaust gas heat utilization and provide sustainable efficient operation of a diesel engine plant on the whole at a safe thermal and environmentally friendly level.

Analysis of the Calorific Value and Specific Gravity of Breadfruit Peel Bioalcohol (Artocarpus Altilis) as an Alternative Fuel at Various Distillation Temperatures

“…This is because at a high temperature of 90ºC it is closer to the boiling point of water by 100ºC, so that the water also evaporates and mixes with the alcohol. This is confirmed by the theory which states that the calorific value is inversely proportional to the water content (Lu et al, 2019;Yang et al, 2022). The composition of the ethanol content in the samples tested influences the calorific value of the fuel.…”

Research of hydrodynamic processes in the flow part of a low-flow thermopressor

“…A general way to increase the efficiency of power plants is to utilize the exhaust heat [1][2][3] and cool the working fluid [4] to provide favorable conditions for their efficient operation by application of waste heat recovery chillers [5,6] or electrically driven vapor compression refrigeration machines as in air conditioning system [7,8]. The air is a general working fluid in the majority of the power plants based on combustion engines, in particular, gas turbines [9,10], internal combustion engines [11,12], as well as in air conditioning systems as subsystems which provide processing (cooling) engine intake air or as autonomous systems in stationary [13][14][15] and transport application [16,17].…”

Innovative approaches and modified criteria to improve a thermodynamic efficiency of trigeneration plants

“…Different heat exchangers might be used to intensify heat transfer [17,18] in utilizing [19,20] and heat transforming contours [21,22]. Besides, special jet devices [23,24], using high pressure potential, can be applied for circulation of working fluids such as ejectors and thermopressors [25,26] in stationary and transport applications [27,28].…”