Turbocharging strategy among variable geometry turbine, two-stage turbine, and asymmetric two-scroll turbine for energy and emission in diesel engines

Zhu, Dengting; Sun, Zhenzhong; Zheng, Xinqian

doi:10.1177/0957650919891355

Cited by 10 publications

(8 citation statements)

References 50 publications

(49 reference statements)

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“…There is a long history of studying how to improve the power of an internal combustion engine and achieve the goals of energy conservation and emission reduction based on a supercharging system. An advanced high supercharging system can improve the supercharging ratio and efficiency of the supercharging system and reduce the exhaust energy loss, thus greatly improving the specific power and fuel economy of the engine …”

Section: Research Status Of Variable-altitude Turbocharging Systemsmentioning

confidence: 99%

“…An advanced high supercharging system can improve the supercharging ratio and efficiency of the supercharging system and reduce the exhaust energy loss, thus greatly improving the specific power and fuel economy of the engine. 67 However, all of these studies were done in plain environments. In order to improve the adaptability of a supercharger to a high-altitude environment, improve the high-altitude power of the internal combustion engine.…”

Section: Research Status Of Variable-altitude Turbocharging Systemsmentioning

confidence: 99%

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Summary of Turbocharging as a Waste Heat Recovery System for a Variable Altitude Internal Combustion Engine

et al. 2023

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The increase in altitude causes the decrease in internal combustion engine power and the increase in pollutant emission. Converting waste heat into more useful forms of energy through the recovery of waste heat from internal combustion engines is the most promising mechanism for improving both of these goals. This paper comprehensively reviews the development and research of waste heat recovery technology of an internal combustion engine in a variable altitude environment. It is found that exhaust gas turbocharging is the most promising waste heat recovery technology to restore high-altitude internal combustion engine power. Turbochargers are affected by low temperature and low pressure at high altitudes, resulting in poor environmental adaptability, inadequate supercharging ratios, and decreased supercharging efficiency. Therefore, it is very important to select the high pressurization system facing the plateau area and its reasonable matching characteristics. The quality of exhaust energy determines how much waste heat a turbine can recover, and only the exergy part of exhaust energy can realize heat/work conversion. The main disadvantage of turbocharging technology applied in the plateau area is that the speed ratio deviates from the design value, leading to the increase of flow loss inside the supercharger. Therefore, optimizing the internal flow field of a high-altitude supercharger is a key problem to improve the efficiency of energy recovery. The conclusion drawn from this Review is that a two-stage turbocharging system will be a key technology to improve the thermal efficiency and reduce the fuel consumption of high-altitude internal combustion engines in the coming decades. In addition, the efficient utilization of the exhaust energy of the two-stage turbine and the influence of the variable compression process of the two-stage compressor on the working medium in the cylinder will be the focus of future research.

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Section: Research Status Of Variable-altitude Turbocharging Systemsmentioning

confidence: 99%

Section: Research Status Of Variable-altitude Turbocharging Systemsmentioning

confidence: 99%

Summary of Turbocharging as a Waste Heat Recovery System for a Variable Altitude Internal Combustion Engine

et al. 2023

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“…The exhaust flow was designed to be split into two manifolds, thereby lowering the overall engine backpressure as well as decreasing pumping losses-especially at medium and high loads. Zhu et al [70] performed numerical studies to guide the diesel engine turbocharging strategy, with variable geometry and two-stage, asymmetric twin-scroll turbocharging under various EGR rates. When higher EGR driving rates (>29%) were applied, asymmetric twin-scroll turbocharging was the best option, with lower pumping loss and lower BSFC.…”

Section: Technologies Of Pumping Loss Reductionmentioning

confidence: 99%

A Review of Energy Loss Reduction Technologies for Internal Combustion Engines to Improve Brake Thermal Efficiency

Wang

Shuai

et al. 2021

Energies

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Today, the problem of energy shortage and climate change has urgently motivated the development of research engaged in improving the fuel efficiency of internal combustion engines (ICEs). Although many constructive alternatives—including battery electric vehicles (BEVs) and low-carbon fuels such as biofuels or hydrogen—are being put forward, they are starting from a very low base, and still face significant barriers. Nevertheless, 85–90% of transport energy is still expected to come from combustion engines powered by conventional liquid fuels even by 2040. Therefore, intensive passion for the improvement of engine thermal efficiency and decreasing energy loss has driven the development of reliable approaches and modelling to fully understand the underlying mechanisms. In this paper, literature surveys are presented that investigate the relative advantages of technologies mainly focused on minimizing energy loss in engine assemblies, including pistons and rings, bearings and valves, water and oil pumps, and cooling systems. Implementations of energy loss reduction concepts in advanced engines are also evaluated against expectations of meeting greenhouse gas (GHG) emissions compliance in the years to come.

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“…However, engine fuel consumption increases owing to pumping loss from HP-EGR. [3][4][5][6] Many measures have been proposed to reduce pumping loss and fuel consumption, such as variable nozzle turbine (VNT), 7 twin entry radial inflow turbines with different flow admission conditions, 8 asymmetric twin-scroll turbocharger 9 double exhaust gas recirculation circuits, 10 and two wastegates. 11 In addition, to meet the stringent requirements of the main emission limits of China VI, 12,13 a higher EGR rate is required for reducing the cost of tail gas after-treatment systems by suppressing NOx generation.…”

Section: Introductionmentioning

confidence: 99%

Effect of the design parameters of induced structures on the sensitivity of compressor efficiency and static pressure of induced structure inlets

Zhu

Wang

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part D:

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A gas-entraining diffuser exhaust gas recirculation (EGR) was proposed to induce the entry of the exhaust gas into the diffuser, to completely utilize the lower static pressure at the diffuser for reducing engine fuel consumption owing to the low engine backpressure. Thus, the induced structure was designed such that a large amount of exhaust gas enters the compressor diffuser. To improve the compressor efficiency and reduce the static pressure at the induced structure inlet, the design parameters of the induced structure (induced angle, induced effective inlet area, parallel part width, and position of the induced structure inlet) were investigated using numerical methods. The results show that the peak compressor efficiency reduced by 4% compared with the compressor prototype, and up to 90% of the compressor efficiency reduction is attributed to the induced gas entering the diffuser, except for the 10% induced gas ratio scenario over the near-choking point. This is because the entropy generation of the induced structure is close to 10% of the entropy generation increase in the diffuser system due to the induced gas at a medium flow rate. Second, in most cases, the compressor efficiency and static pressure of the induced structure inlet increase or decrease simultaneously as the design parameters vary. To select the best induced structure, it is necessary to compromise between the compressor efficiency and static pressure of the induced structure inlet. In fact, the compressor efficiency changes by less than 1% by varying the design parameters of the induced structure, compared with case ID1. This demonstrates that the design parameters have little effect on the compressor efficiency. Compared with the compressor efficiency, the static pressure of the induced structure inlet is more sensitive to the design parameters, particularly the induced effective inlet area and the position of the induced structure inlet.

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Turbocharging strategy among variable geometry turbine, two-stage turbine, and asymmetric two-scroll turbine for energy and emission in diesel engines

Cited by 10 publications

References 50 publications

Summary of Turbocharging as a Waste Heat Recovery System for a Variable Altitude Internal Combustion Engine

Summary of Turbocharging as a Waste Heat Recovery System for a Variable Altitude Internal Combustion Engine

A Review of Energy Loss Reduction Technologies for Internal Combustion Engines to Improve Brake Thermal Efficiency

Effect of the design parameters of induced structures on the sensitivity of compressor efficiency and static pressure of induced structure inlets

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