This article investigates the effect of using three nanofluids as exhaust gas cooling fluid in an EGR cooler. Reducing the exhaust temperature of diesel engines can reduce environmental and thermal pollutants. In a conventional 3-liter engine in all kinds of vehicles, 20 to 40 kW of its 115 kW power is being wasted. The engine shell temperature rises to 600 degrees Celsius.  Exhaust gas recirculation can recover a part of it. Exhaust gas recirculation can recover thermal energy by exhaust gas recirculation method by charging a thermal energy storage tank to feed a diesel engine in cold start.Many researchers have simulated natural convection in the nanofluids. The innovation of the current research is the use of 61 tubes inside the small heat exchanger that is cooled by the discussed nanofluids in the exhaust gas recirculation system of the diesel engine that works with the paraffin phase changer and the exhaust gas recirculation rate is 60% to Reduce of environmental pollution and smoother operation of diesel engine. The inlet is steady state turbulent. The thickness of the inner tubes is considered close to zero. The shell is adiabatic. Both of them exit the heat exchanger under pressure. Three nanoparticles of diamond, silicon dioxide, and copper are considered. This numerical simulation has solved the continuity equations, energy, Navier-Stokes, the pressure drop along the pipe, flow, and rotation equation, kinetic energy disturbance, and energy loss rate equation. The results showed a higher pressure drop for the silicon dioxide-ethylene glycol nanofluid. Silicon dioxide-ethylene glycol nanofluid has a higher Nusselt number, slightly different from other nanofluids. Also, Copper ethylene glycol has a lower Velocity among nanofluids

Increase of environmental pollution and restricted emission legislations have forced companies to produce automobiles with lower air pollutants. In this respect, discharge of blowby gases into the environment has been prohibited and their recirculation into the combustion chamber is proposed as an alternative solution. In addition, using EGR technique to control and reduce nitrogen oxides in internal combustion engines has been quite effective. An important common feature of these two methods is the fact that improper EGR/blowby distribution leads to the increase in other pollutants and the significant engine power reduction. Therefore, the study of important factors in maldistribution of the injected gases is of great practical importance. Besides the injection position that has significant role on distribution of injected gases, it seems that other parameters such as engine speed, injection velocity and angle may affect the distribution of injected gases. In this numerical study, a new technique is used to determine the effect of these parameters on distribution of injected EGR or blowby gases into the EF7 intake manifold. Numerical calculations are performed for three injection velocities, five injection angles and three different engine speeds. It was found that recirculated gases distribution is slightly influenced by the injection angle and injection velocity, while the engine speed is the most influential factor.

One of the major goals for manufacturers of turbocharged spark ignited (SI) engines is to increase the knock resistance at high loads. In order to move out of knocking combustion, timing of the spark ignition is retarded, thus limiting the maximum pressure and temperature in the combustion chamber. This is an effective method to eliminate the knock. The negative effect of retarding spark timing is increasing the exhaust gas temperature. In order to reduce the exhaust gas temperature, rich mixtures are normally used. As a result, the fuel consumption increases. The cooled EGR can be used to solve this problem. Using the cooled EGR decreases the pressure and the temperature in the unburned zone. There are a number of different possible architectures, each with its specific characteristics. Main objectives of this study were to quantify the increase the knock resistance and to decrease the enrichment in order to the target stoichiometric operation over the full operating range. All the simulations were carried out in the GT-POWER Software on the EF7-TC engine.

In the diesel engine Exhaust Gas Recirculation (EGR) components, valve and connecting pipes are the critical components and often fail during new engine development. These components are important for meeting NOx emission norms. Thus design of these components should remain robust. The compact packaging of complete EGR components on the engine, however, is counted as a designing challenge in which the consequent vibration-related failure plays a major role. Normally in pneumatic EGR valve, shaft spring stiffness is considered important for shaft opening and closing. But during emission testing in this layout, shaft is self-opened without feedback signal from sensor; this is due to resonance where the problem is solved by increasing the spring stiffness. The next key components are the EGR pipes; the flexible bellows on these pipes are useful for thermal expansion during hot conditions. In this case the bellow crack failure is observed due to vibration. Therefore, design improvements due to proper design of bellow geometry and bracket support for these pipes facilitated prevention of EGR pipe failure. This paper also describes the methodology of conducting proper failure investigation to identify the root cause for vibration-related failures of EGR system during new product development.

Cooled exhaust gas recirculation is emerging as a promising technology to address the increasing demand for fuel economy without compromising performance in turbocharged spark injection engines. The objectives of this study are to quantify the increase in knock resistance and to decrease the enrichment and emission at high load. For this purpose four stroke turbo charged Spark Ignition engine (EF7-TC) including its different systems such as inlet and exhaust manifold, exhaust pipe and engine geometry are modeled using GT Power Software. As predicted, using cooled EGR at high load enabled operation at lambda near to one with the same serial engine performances, which offers substantial advantages Such As BSFC reduction (up to 14%), and emission reduction (CO, NOx).