Hydrogen Containing Nanofluids in the Spark Engine’s Cylinder Head Cooling System

The article is devoted to the following issues: boiling of fluid in the cooling jacket of the engine cylinder head; agents that influenced the thermal conductivity coefficient of nanofluids; behavior of nanoparticles and devices with nanoparticles in the engine’s cylinder head cooling system. The permissible temperature level of internal combustion engines is ensured by intensification of heat transfer in cooling systems due to the change of coolants with “light” and “heavy” nanoparticles. It was established that the introduction of “light” nanoparticles of aluminum oxide into the water in a mass concentration of 0.75% led to an increase in its thermal conductivity coefficient by 60% compared to the base fluid at a coolant temperature of 90 °C, which corresponds to the operating temperature of the engine cooling systems. At the indicated temperature, the base fluid has a thermal conductivity coefficient of 0.545 W/(m °С), for nanofluid with particles its value was 0.872 . At the same time, a positive change in the parameters of the nanofluid in the engine cooling system was noted: the average movement speed increased from 0.2 to 2.0 m/s; the average temperature is in the range of 60–90 °C; heat flux density 2 × 102–2 × 106 ; heat transfer coefficient 150–1000 . Growth of the thermal conductivity coefficient of the cooling nanofluid was achieved. This increase is determined by the change in the mass concentration of aluminum oxide nanoparticles in the base fluid. This will make it possible to create coolants with such thermophysical characteristics that are required to ensure intensive heat transfer in cooling systems of engines with various capacities.

Analisa Kegagalan Conrod Bearing Pada Kapal Cepat

Kerusakan conrod bearing pada main engine kapal cepat akibat design material, peningkatan panas yang berlebih pada sistem engine cooling (overheat) dan pengeoperasian. Untuk mengidentifikasi penyebab kerusakan dilaksanakan beberapa pengujian seperti pengamatan visual makro, analisis komposisi kimia, kekerasan mikro dengan vickers, fraktografi,metalografi, pengukuran ketebalan lapisan. Hasil analisis telah terjadi overheating dan deform pada conrod bearing akibat bergesekan dengan connecting rod dan terlihat pada daerah tepi alur adanya gesekan, dan tidak ditemukan lapisan babbit dikarenakan lapisan tersebut sudah lebur (fase liquid) pada temperature 354°C sesuai dengan standar logam babbit ASTM B23-00 2014 serta lapisan back steel mengalami deform.

Engine Cooling Device of New Energy Vehicle

With the environmental pollution and the shortage of oil resources becoming more and more serious, the development and application of new energy vehicles have attracted more and more attention. Engine is an important part of new energy vehicles, and its performance has a great impact on the vehicle. Compared with traditional industrial motors, new energy vehicle engines have higher requirements on power density, and the improvement of power density poses new challenges to the design of motor cooling system. The purpose of this paper is to study the engine cooling device of new energy vehicles and improve the overall performance of the vehicle. The main research content of this paper is to lay a foundation for the theoretical basis of the engine cooling device, elaborate the working principle of the motor cooling system and the loss of the motor in operation. Then, the heat dissipation system of permanent magnet synchronous motor based on heat pipe is studied experimentally. Aiming at the problem of only considering the temperature rise and ignoring the pressure loss in the flow channel design, a flow channel design method considering the motor temperature rise and the flow channel pressure loss is proposed, and the motor flow channel is optimized. The test results show that the maximum temperature rise at the end is close to 16.56 °C, which is in good agreement with the simulation results. It shows that the heat pipe based heat dissipation system can effectively reduce the temperature rise of motor winding, which provides a new idea for the heat dissipation design of permanent magnet synchronous motor

Thermohydraulic Performance Optimization of Automobile Radiators Using Statistical Approaches

Automobile radiator which is one of the vital components used for engine cooling in vehicles, is expected to provide higher thermal performance without changing the exterior dimensions of the radiator with the development of engine technology. This situation necessitates changes in both design and operating parameters in the currently used radiator. In the present study, all fundamental parameters affecting the thermal and hydraulic performance of an automobile radiator are evaluated and optimized with statistical methods. Optimization study is carried out using Taguchi and ANOVA methods for two specified objective functions (heat transfer and pressure drop). The order of importance and impact rates for each design and operating parameter, the best and worst working conditions in terms of both target functions are determined. Air velocity, air inlet temperature, coolant inlet temperature and fin pitch are found to be the most effective parameters on the heat transfer with a contribution ratio of 88%. The best and worst working conditions are obtained for the heat transfer and under these working conditions, they are calculated as 43.68 kW and 1.63 kW, respectively. When the system is examined in terms of the pressure drop, the results show that the coolant flow rate and tube height have a great impact with a contribution ratio of 67.04% and 32.06%, respectively. Lastly, the maximum and minimum pressure drop within the studied operating condition range, are determined as 20.68 kPa and 0.12 kPa, respectively.

Challenges and development directions of membrane bioreactors operated on passenger ships in international shipping

In membrane bioreactor (MBR) technology, the activated sludge method is integrated with the separation of solid particles by ultrafiltration (UF). The technology ensures a high effluent quality, a shortened hydraulic retention time and a long sludge age that promotes slowly growing microorganisms and low sludge production. These advantages and the modular construction mean that MBRs have started to treat wastewater generated on passenger ships to adjust the treatment systems to the International Convention for the Prevention of Pollution from Ships. The aim of this paper is to present operational aspects of MBRs treating wastewater generated on ships, which are different from the aspects of MBR operation on land. This paper describes the consequences of separate treatment of gray wastewater (from showers, washing machines and kitchens) and black wastewater (from toilets), and of discontinuous flow of wastewater resulting from very high variability in the passenger numer and the use of the MBR as a ship ballast element. The possibility of introducing a water recovery technology using the existing infrastructure on passenger ships as well as the hybrid UF/reverse osmosis technology is presented. The findings demonstrated that gray effluent may be reused for marine main engine cooling jackets of high and low temperature, ship boilers or ship laundry.

Development of on-line neural network based adaptive fractional-order sliding mode robust controller on electromechanically actuated engine cooling system

The reduction of temperature fluctuations around desired reference and control input energy for cooling actuators are among the most important aims of engine thermal management system. However, maintaining of engine/radiator outlet temperature within certain limits is a challenging process in different engine operating conditions due to unknown in-cylinder variable heat transfer rate in terms of the control theory. For this purpose, the thermodynamic model is obtained by dividing into two subsystems, such as the engine and the radiator subsystem in the presence of unknown heat transfer rate, external disturbance, and uncertainties in this study. To increase system robustness, tracking engine inlet/outlet temperature control of engine cooling components is performed using the adaptive fractional-order sliding mode control structure. Moreover, the disturbances acting on the system and unknown heat transfer dynamics of the system are estimated with a radial basis function on-line neural network estimator. The efficiency of proposed controller strategy for electromechanically actuated engine cooling system is compared by proportional–integral–derivative and classical integral sliding mode control under the NEDC (New European Driving Cycle) and WLTP (Worldwide Harmonized Light Vehicles Procedure) transient operating conditions. The temperature error tracking performance is tested by paying attention integral square error, integral absolute error, integral time-weighted absolute error along to the driving cycles. The obtained results showed that the adaptive fractional-order sliding mode control–based engine cooling system outperforms compared to the optimally gain tuned proportional–integral–derivative and integral sliding mode control schemes in terms of reducing of tracking error and engine cooling actuators energy consumption for all engine operating cycles.