Firstly, Any simulation of air flow through turbocharger compressor.
As we all know, compressors have been widely used as effective method to improve the performance and decrease the emissions of diesel engines. The increasingly strict emission regulations and heavy exhaust gas recirculation are likely to push the engine operating conditions toward less efficient or even unstable regions. Under this situation, low speed and high load working conditions of diesel engines require the turbocharger compressors to supply highly boosted air at low flow rates, however, the performance of turbocharger compressors is usually limited under such operating conditions.
Therefore, improving turbocharger efficiency and extending the stable operating range are becoming critical for viable future low emission diesel engines. CFD simulations carried out by Iwakiri and Uchida showed that a combination of both the casing treatment and variable inlet guide vanes could provide wider operating range by comparing than that using each independently. The stable operating range is shifted to lower air flow rates when the compressor speed is reduced to 80,000 rpm. However, at 80,000 rpm, the stable operating range becomes narrower, and the pressure ratio becomes lower; these are mainly due to the reduced tangential flow at the impeller exit.
Secondly, the water-cooling system of turbocharger.
An increasing number of efforts have been tested to improve the cooling system in order to rise the output by more intensive use of active volume. The most important steps in this progression are the change from (a) air to hydrogen cooling of the generator, (b) indirect to direct conductor cooling, and finally (c) hydrogen to water cooling. The cooling water flows to the pump from a water tank which is arranged as a header tank on the stator. From the pump water first flows through a cooler, filter, and pressure regulating valve, then travels in parallel paths through the stator windings, main bushings, and the rotor. The water pump, together with the water inlet and outlet, are included in the cooling water connection head. As a result of their centrifugal force, a hydraulic pressure is established by the water columns between the water boxes and coils as well as in the radial ducts between water boxes and central bore. As mentioned before, the differential pressure of the cold and hot water columns due to water temperature rise acts as a pressure head and increases the quantity of water flowing through the coils in proportion to the increase of water temperature rise and centrifugal force.
Reference
1. Numerical simulation of air flow through turbocharger compressors with dual volute design, Energy 86 (2009) 2494–2506, Kui Jiao, Harold Sun;
2. PROBLEMS OF FLOW AND HEATING IN ROTOR WINDING, D. Lambrecht*, Vol I84
Post time: Dec-27-2021