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Nizhniy Novgorod, Russia

Kirillov V.A.,RAS Boreskov Institute of Catalysis | Samoilov A.V.,RAS Boreskov Institute of Catalysis | Shigarov A.B.,RAS Boreskov Institute of Catalysis | Ivanov D.A.,Moscow State University of Mechanical Engineering | Zaletov D.V.,Mobil GazService Ltd
Biosciences Biotechnology Research Asia | Year: 2015

This work discusses the issues of thermochemical recovery as a method to improve efficiency of fuel utilization in external heat engines (EHE). The article presents thermodynamic analysis of efficiency of external thermochemical recovery (TCR) upon steam reforming of low alcohols, as well as efficiency of internal TCR upon steam reforming of methane. The issues of selection of catalysts are considered and mathematical simulation of variants of TCR solutions with regard to EHE operating by the Stirilng and Rankine cycle is performed. Variants of technical solutions of catalytic heat exchangers with external, internal and combined heat input are analyzed in thermodynamic cycles of EHE, as well as of internal combustion engines (ICE) with respect to thermochemical recovery. Variants of implementation of external and internal TCR have been studied. It is demonstrated that the most promising variants of heat recovery is the external TCR with application of oxygen-containing compounds as fuels, characterized with low point of conversion into synthesis gas (SG). A mathematical model is developed for numerical analysis of devices for TCR of heat in the combustion products of Rankine engine heater. The influence of working fluids on the cycle efficiency is analyzed, it is demonstrated that the most promising variants are gaseous carbon dioxide and ammonia. Source


Khripach N.A.,Moscow State University of Mechanical Engineering | Papkin B.A.,Moscow State University of Mechanical Engineering | Korotkov V.S.,Moscow State University of Mechanical Engineering | Nekrasov A.S.,Moscow State University of Mechanical Engineering | Zaletov D.V.,Mobil GazService Ltd
Biosciences Biotechnology Research Asia | Year: 2015

This paper presents a study of how a thermoelectric generator can affect the vehicle fuel efficiency in a real-world environment. Real-world drive cycles are significantly different from the standard cycles, which certainly has a negative impact on fuel economy. Given low share of hybrid vehicles, it is advisable to assess the impact of a thermoelectric generator, which partially recovers thermal energy of exhaust gases, on fuel efficiency of a vehicle with a conventional power plant. Tests were run at actual vehicle routes and involved registration of thermodynamic parameters of exhaust gas and coolant in addition to the basic parameters of the vehicle and its internal combustion engine. The results were used to calculate the electric output of the thermoelectric generator at each moment of time, which allows to evaluate its effect on the fuel economy of the vehicle as a whole. The results showed an improvement of the internal combustion engine fuel consumption of about 3% after installation of a thermoelectric generator, which is significantly less than known simulation results based on standard driving cycles. It can be explained by sudden powerful accelerations of the vehicle during the test drives as well as other factors. Source


Khripach N.A.,Moscow State University of Mechanical Engineering | Papkin B.A.,Moscow State University of Mechanical Engineering | Korotkov V.S.,Moscow State University of Mechanical Engineering | Zaletov D.V.,Mobil GazService Ltd
Biosciences Biotechnology Research Asia | Year: 2015

This article presents a study of the influence of design parameters, such as the thickness and width of thermal fins and inter-fin grooves, on the performance of a thermoelectric generator for an automotive internal combustion engine. The overall dimensions of a thermoelectric generator and, as a consequence, the size of the surface, which exchanges heat with the exhaust gases, are often subject to limitations because it has to fit inside the vehicle's exhaust system. Changing the thermoelectric generator body design by adding fins that increase the heat exchange area can significantly increase the amount of the recuperated thermal energy. However, it inevitably increases the exhaust gas pressure drop in the thermoelectric generator, which is certainly a negative impact on the internal combustion engine as a whole. According to our research methodology the fin thickness ranged from 0.75 to 5.0 mm and the groove width from 1.0 to 8.0 mm. Consequently, we considered 48 variants of the thermoelectric generator heat exchanger in total. The obtained results show a high degree of non-uniformity of temperature distribution in the cross sections of the thermoelectric generator, which leads to uneven heating of the thermoelectric generator modules, reduced efficiency and overheating. This research enabled us to select a design of the fins, which allows to achieve the heat flow through the thermoelectric generator modules of 19kW with exhaust gas pressure drop of 2.5 kPa, while taking into account additional technical solutions. This research helps to improve the technical and economic parameters of a thermoelectric generator for an automotive internal combustion engine at the model design stage, which significantly accelerates the process of its development. Subsequent laboratory tests of the developed thermoelectric generator model enable us to refine the parameters of the mathematical model and significantly improve accuracy of the calculations. Source


Lezhnev L.Y.,Moscow State University of Mechanical Engineering | Ivanov D.A.,Moscow State University of Mechanical Engineering | Zaletov D.V.,Mobil GazService Ltd
Biosciences Biotechnology Research Asia | Year: 2015

This paper presents an algorithm to control the motion of the displacer and the working piston of a free-piston Stirling engine (FPSE). An active control method is used to correct the motion of the pistons, which allows to adjust the pressure in the gas spring (GS) of the displacer, compression space and the buffer chamber (BC) for each operating cycle. The pressure changes inside the spaces fit in a narrow range. They are aimed to compensate the working fluid (WF) flow-over between the inner spaces of FPSE due to leakages through the sealings. The proposed algorithm and means for its implementation allow to adjust the range of the displacer and working piston travel and keep the phase angle and average WF pressure in the inner spaces within a calculated range. Combination of these parameters ensures stability of the self-oscillating process in FPSE. Source

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