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This research presents an investigation of an energy recovery solution from exhaust gases in internal combustion based on the heat exchange to distil fresh water from the sea water. Consequently, an optimization of the flow field design of the heat exchanger was performed using the commercial computational fluid dynamics (CFD) software. The result...
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... on the parameters of this engine, the engine model was built in AVL-Boost to simulate its operation. Consequently, the exhaust gas flow was calculated and considered as the inlet boundary conditions for the heat exchanger as shown in Table 1. Fig. 3 shows the temperature distributions of the exchanger corresponding to a variety of the engine loads and reference locations. ...Citations
... As a result, the engine load which can reach 33% when the engine is completely loaded is the only factor affecting the energy recovery of the exchanger. [9] Giuseppe-Bianchi et al (2015) Presented a vane pumps work to save energy and vane expanders the slide was used to efficiently convert energy into a mechanical form, where the energy recovery performance of the power unit equipped with sliding spray machines was evaluated using lubricating oil as a heat source, where 1.7 kilowatts were recovered in mechanical form, and the power unit was tested based on ORC with an internal combustion engine at some operating points where the mechanical power recovered was up to 1.9 kilowatts [10]. To fulfill future energy needs and cut carbon emissions, it is essential to harvest energy from the environment. ...
... The waste heat in the cooling system as well as that in flue gases can be recovered within the thermodynamic limits available based on technology applied [44,62]. The performance of exhaust waste heat recovery systems is a function of engine load, and recovery technology reached but can generally be between 25% and 35% of the waste heat in the exhaust [63,64]. Other important parameters for exhaust heat recovery are the quality of heat source, evaporator quality, system output and loading, and complicity of the system [20]. ...
Waste heat recovery systems convert the thermal energy in waste fluid streams into useful work. Diesel engine cogeneration systems are waste recovery systems using technologies and devices with main elements being the diesel engine prime movers, the electric generator, Rankine cycle steam turbine, exhaust heat recovery boiler super heaters, and control and instrumentation devices. Diesel engines exhaust significant recoverable heat energy that can be converted to extra electricity using a Rankine cycle plant. In this study, the cogeneration potential of an operating diesel engine power plant was established. The cogeneration potential of a 119.7 MW operating power plant in Kenya is established. The study showed that subject to limits imposed by presence of sulphur in fuel and hence existence of sulphur dioxide in the exhaust, each engine of capacity 17.1 MWe has recoverable thermal energy of about 1.33 MWth while the whole plant with seven engines is about 9.3 MWth for the 7 engines at plant optimum loading conditions which can generate 8.5 MWe extra electricity under optimum conditions. The study recommends the development of up to 9 MWe Rankine cycle steam turbine-based cogeneration power plant. Diesel power plant cogeneration is a technically and economically viable strategy to increase the generation efficiency of diesel power plants and reduce the pollution intensity and financial performance of the diesel power plant leading to reduction in cost of power and higher return on investment for investors.
The utilization of waste exhaust heat energy into inlet preheated air is investigated using heat pipe heat exchanger. This study focuses on waste heat energy, which comes out as exhaust from standalone diesel engine is around 60–70%, this energy is converted into preheated air and supplied as inlet air for the engine using heat pipe with DI water as working fluid. This preheated air makes improvement in efficiency of the engine and is economically effective in all conditions. In this study, the effect of specific fuel consumption (SFC), brake thermal efficiency (BTE), smoke intensity, oxides of nitrogen (NOx), carbon monoxide (CO), and hydrocarbon (HC) emissions is reported for various loads ranging from no load to loaded (0–90%). The results are compared with and without heat pipe conditions and performance is analyzed. The study warranted that at 38 °C as input temperature and 50% load condition, the better performance is achieved for SFC as 0.23 kg/kW h and 37% for BTE. The observation reports as influence of heat pipe for utilizing the waste exhaust heat makes improved in the performance of the engine.
Biogas is a renewable energy resource that can play a leading role in the sustainable energy transition through green electricity generation. Biogas can be converted to electricity and renewable fuels through different technologies and prime movers. Prime movers that can be used for biogas power generation include gas and steam turbines, diesel engines, Otto cycle engines, Stirling engines as well as direct conversion in fuel cells. Since biogas has high octane rating, it can be used directly or with minimal modifications in spark ignition or petrol engines, but needs several modifications for use in dedicated diesel biogas engines or dual fuel engines and bi engines. The dual fuel mode which uses biomethane or biogas and diesel requires little or no engine modifications unlike the conversion to a dedicated gas engine. The performance of biogas prime movers is greatly enhanced if enriched biogas or biomethane is used in place of raw biogas. Other than use in various engines, biogas can be cleaned and used in fuel cells and manufacture of renewable hydrogen. As renewable natural gas, biogas in the form of biomethane can be injected to the natural gas grids for domestic and industrial application as natural gas substitute in applications which include power generation.
Designing and manufacturing a combined system that utilizes the thermal energy of coolant and exhaust gases from Internal Combustion Engines (ICE) to distill fresh water from seawater on Vietnamese offshore fishing vessels is an education ministry-level project that the research team is working on. Utilizing this heat sources not only improve heat efficiency, but also provide fresh water on equipped vehicles. The experimental process shows that, the heat energy emission changes consecutively according to the ICE modes, directly affects the performance of the heat recovery equipment as well as the performance of the system. The content of this paper will present the process of designing a waste heat recovery tube by assessing the effect of heat exchanger structure in exhaust heat recovery equipment to the heat transfer efficiency between exhaust gases and sea water. The studies were conducted on Ansys Fluent software, in which the input data was determined from experimental data. The research results depict that the exhaust heat recovery efficiency is highly dependent on the heat exchanger fins structure. With a reasonable format, the heat recovery efficiency can reach up to 40% in most engine operating modes which lead to an improvement of approximately 12% of the total input energy.
In the Internal Combustion Engine (ICE) working operation, fuel is fed into the combustion chamber, where it is burnt in air to convert the chemical energy of fuel into heat according to the first law of thermodynamics. However, the amount of energy transformed into actual power is only 21-33% and 25-40% for gasoline engines and diesel engines, respectively. Consequently, about two-thirds of the remaining energy is lost due to the heat transfer to the surrounding environment, in which the heat energy removed by the exhaust occupies the largest proportion (about 30-35%). Therefore, utilizing the regenerative heat from the exhaust gases is a potential solution to improve the ICE’s efficiency. This paper presents the simulation results of the effect of heat exchange tube structure on waste recovery capacity in the system, which utilizes the heat of exhaust gases and cooling water of ICE based on Ansys Fluent. In addition, the boundary conditions, the flow, and exhaust temperature are determined by simulating the engine’s working process using AVL-Boost. This research shows that the heat utilization efficiency of exhaust energy can be achieved up to 34%, corresponding to a reasonable structure. This research’s study outcomes are the foundation to implement the complete design of the heat waste recovery system of ICE.
