Experimental Study of Ion Current Signals and Characteristics in an Internal Combustion Rankine Cycle Engine Based on Water Injection

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Zhe Kang ◽  
Zhijun Wu ◽  
Lezhong Fu ◽  
Jun Deng ◽  
Zongjie Hu ◽  
...  
Keyword(s):  
Water Vapor ◽  
Water Injection ◽  
Rankine Cycle ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Ion Current ◽  
Pure Oxygen ◽  
Current Signal ◽  
Injection Process ◽  
Current Detection

The internal combustion Rankine cycle (ICRC) engine utilizes pure oxygen as the oxidant instead of air during combustion to prevent the generation of nitrogen oxide emissions and lower the cost of CO2 recovery. To control combustion intensity and increase efficiency, water injection technology is implemented as it can increase the in-cylinder working fluid during combustion process. To further enhance the system thermal efficiency, the injected water is heated using coolant and waste heat before being directly injected into combustion chamber. The main challenge of controlling the ICRC engine is the interaction between water injection process and combustion stability. Ion current detection provides a potential solution of real-time detection of in-cylinder combustion status and water injection process simultaneously. In this paper, the characteristics of ion current signal in an ICRC engine were studied. The results indicate the ion current signal is primarily affected by the combination of trapped water vapor injected in the last cycle and in-cylinder combustion intensity. The water vapor contributes to the ionization reactions, which lead to enhanced ion current signals under water cycle. The ion current signal is capable of reflecting the operating conditions of the in-cylinder water injector. The phase of the ion current peak value has a linear relation as the water injection timing is delayed, and ion current detection technology has the potential to detect the combustion phase under different engine loads in an internal combustion Rankine cycle engine.

scholarly journals Chemical kinetic analysis of in-cylinder ion current generation under direct water injection within internal combustion Rankine cycle engine

2021 ◽  
pp. 161-161
Author(s):  
Zhe Kang ◽  
Yang Lv ◽  
Nanxi Zhou ◽  
Lezhong Fu ◽  
Jun Deng ◽  
...  
Keyword(s):  
Initial Temperature ◽  
Water Injection ◽  
Rankine Cycle ◽  
Internal Combustion ◽  
Chemical Kinetic ◽  
Ion Current ◽  
Residual Water ◽  
Current Signal ◽  
Injection Process ◽  
Direct Water Injection

Direct water injection provides feasible solution for combustion optimization and efficiency enhancement within internal combustion Rankine cycle engine, while the feedback signal of close-loop direct water injection control is still absent. Ion current detection monitors in-cylinder electron variation which shows potential in revealing direct water injection process. For better understanding of unprecedented augment of ion current signal under direct water injection within internal combustion Rankine cycle engine, a chemical kinetic model is established to calculate the effect of intake oxygen fraction, fuel quantity, initial temperature and residual water vapor on in-cylinder electron formation based on GRI Mech 3.0 and ion current skeleton mechanism. The simulation results indicate direct water injection process show significant impact on in-cylinder electron formation through chemical interactions between H2O and other intermedia species including HO2, O2, CH3 and H, these reactions provides additional OH radical for propane oxidation facilitation, which result in large portion of CH radical formation and therefore, lead to higher in-cylinder electron generation. The initial temperature plays a vital role in determining whether residual water vapor show positive or negative effect by in-cylinder temperature coordination of direct water injection. Results of this work can be used to explain phenomenon related to direct water injection and ion current signal variation under both internal combustion Rankine cycle or traditional petrol engine.

Carbon Capture for Automobiles Using Internal Combustion Rankine Cycle Engines

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Robert W. Bilger ◽  
Zhijun Wu
Keyword(s):  
Water Vapor ◽  
Power Output ◽  
Power Plants ◽  
High Efficiency ◽  
Co2 Storage ◽  
Rankine Cycle ◽  
Internal Combustion ◽  
Production Costs ◽  
Specific Power ◽  
Specific Power Output

Internal combustion Rankine cycle (ICRC) power plants use oxy-fuel firing with recycled water in place of nitrogen to control combustion temperatures. High efficiency and specific power output can be achieved with this cycle, but importantly, the exhaust products are only CO2 and water vapor: The CO2 can be captured cheaply on condensation of the water vapor. Here we investigate the feasibility of using a reciprocating engine version of the ICRC cycle for automotive applications. The vehicle will carry its own supply of oxygen and store the captured CO2. On refueling with conventional gasoline, the CO2 will be off-loaded and the oxygen supply replenished. Cycle performance is investigated on the basis of fuel-oxygen-water cycle calculations. Estimates are made for the system mass, volume, and cost and compared with other power plants for vehicles. It is found that high thermal efficiencies can be obtained and that huge increases in specific power output are achievable. The overall power-plant system mass and volume will be dominated by the requirements for oxygen and CO2 storage. Even so, the performance of vehicles with ICRC power plants will be superior to those based on fuel cells and they will have much lower production costs. Operating costs arising from supply of oxygen and disposal of the CO2 are expected to be around 20 c/l of gasoline consumed and about $25/tonne of carbon controlled. Over all, ICRC engines are found to be a potentially competitive option for the powering of motor vehicles in the forthcoming carbon-controlled energy market.

Modeling of Ion Current Signal in Diesel Combustion

2013 ◽  
Author(s):  
Fadi Estefanous
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Process ◽  
Operating Conditions ◽  
Ion Current ◽  
Ionization Mechanism ◽  
Diesel Combustion ◽  
Current Signal ◽  
Three Dimensional Model ◽  
Cycle Simulation ◽  
Soot Precursors

Ionization in internal combustion engines produces a signal indicative of in-cylinder conditions that can be used for the feedback electronic control of the engine, to meet production goals in performance, fuel economy and emissions. Most of the research has been conducted on carbureted and port injection spark ignition engines where the ionization mechanisms are well defined. A limited number of investigations have been conducted on ionization in diesel engines because of its complex combustion process. In this study, a detailed ionization mechanism is developed and introduced in a 3-D diesel cycle simulation computational fluid dynamics (CFD) code to determine the contribution of different species in the ionization process at different engine operating conditions. The CFD code is coupled with DARS-CFD, another module used to allow chemical kinetics calculations. The three-dimensional model accounts for the heterogeneity of the charge and the resulting variations in the combustion products. Furthermore, the model shows the effects of varying fuel injection pressure and engine load on the ion current signal characteristics. Ion current traces obtained experimentally from a heavy duty diesel engine were compared to the 3-D model results. The results of the simulation indicate that some heavy hydrocarbons, soot precursors play a major role, in addition to the role of NOx in ionization in diesel combustion.

Simulation on Effect of EGR on Oxy-Fuel IC Engine

2011 ◽  
Vol 130-134 ◽  
pp. 790-795 ◽  
Author(s):  
Xiao Yu ◽  
Zhi Jun Wu
Keyword(s):  
Reaction Rate ◽  
Gasoline Engine ◽  
Water Injection ◽  
Combustion Process ◽  
Engine Performance ◽  
Rankine Cycle ◽  
Ic Engine ◽  
Injection Process ◽  
Working Cycle ◽  
Exhaust Heat

Internal combustion Rankine cycle engine uses oxygen instead of air as oxidant during the combustion process in gasoline engine. Recycled fluid is employed to control the reaction rate and recycles the exhaust heat inside the cylinder as well. CO2 could be recaptured after separated from the exhaust gas (CO2 and water vapor) during condensation, and an ultra-low emission working cycle is achieved. Considering the side effects of water injection process, EGR is employed to control the combustion process and thermal efficiency of the oxy-fuel combustion cycle is calculated and optimized in this paper. Results show that the application of EGR could slow down the combustion process effectively, and appropriate EGR rate matched with ignition timing would control the reaction rate and cylinder pressure, therefore enhance the engine performance.

scholarly journals Exhaust gas heat recovery through secondary expansion cylinder and water injection in an internal combustion engine

2017 ◽  
Vol 21 (1 Part B) ◽  
pp. 729-743
Author(s):  
Toosi Nassiri ◽  
Amir Kakaee ◽  
Hazhir Ebne-Abbasi
Keyword(s):  
Internal Combustion Engine ◽  
Thermal Efficiency ◽  
Combustion Engine ◽  
Water Injection ◽  
Internal Combustion ◽  
Exhaust Gas ◽  
Exhaust Gases ◽  
Injection Process ◽  
Direct Water Injection ◽  
Novel Concept

To enhance thermal efficiency and increase performance of an internal combustion engine, a novel concept of coupling a conventional engine with a secondary 4-stroke cylinder and direct water injection process is proposed. The burned gases after working in a traditional 4-stroke combustion cylinder are transferred to a secondary cylinder and expanded even more. After re-compression of the exhaust gases, pre-heated water is injected at top dead center. The evaporation of injected water not only recovers heat from exhaust gases, but also increases the mass of working gas inside the cylinder, therefore improves the overall thermal efficiency. A 0-D/1-D model is used to numerically simulate the idea. The simulations outputs showed that the bottoming cycle will be more efficient at higher engines speeds, specifically in a supercharged/turbocharged engine, which have higher exhaust gas pressure that can reproduce more positive work. In the modeled supercharged engine, results showed that brake thermal efficiency can be improved by about 17%, and brake power by about 17.4%.

Improving the Efficiency of Power Generation Plants Based on Internal Combustion Engines

2015 ◽  
Vol 752-753 ◽  
pp. 941-945
Author(s):  
Artem Yur’evich Budko ◽  
M.Yu. Medvedev ◽  
Vladimir Vladimirovich Matsiborko
Keyword(s):  
Power Generation ◽  
Spectral Analysis ◽  
Wave Packet ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Ion Current ◽  
Combustion Engines ◽  
Current Signal ◽  
Paper Work

This paper describes a method developed by the authors for the detection and estimation of knock intensity in the cylinders of internal combustion engines. The method is based on the spectral analysis of the ion current signal, which is detected within the combustion chamber of the engine. The method allows estimation of the total wave packet energy for different waves speed and frequency. The estimation results of wave’s energy arising in the normal and knock combustion to engine VAZ 2110 are also presented in the paper work.

Ion Current Detection During Cold Starting and Idling in Diesel Engines

2012 ◽  
Author(s):  
Sanket Gujarathi ◽  
Tamer Badawy ◽  
Naeim Henein
Keyword(s):  
Feedback Control ◽  
Signal Detection ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Ion Current ◽  
Current Signal ◽  
Gasoline Engines ◽  
Cold Starting ◽  
High Concentrations ◽  
Current Detection

Cold starting of diesel engines is characterized by inherent problems such as long cranking periods and combustion instability leading to an increase in fuel consumption and the emission of high concentrations of hydrocarbons which appear as white smoke. The ion current signal has been considered for the feedback control of both gasoline and diesel engines. However, the ion current signal produced from the combustion of the heterogeneous charge in diesel engines is weaker compared to that produced from the combustion of the homogeneous charge in gasoline engines. This presents a problem in the detection of the ion current signal in diesel engines, particularly during starting and idling operations. This paper investigates and addresses the ion current detection problems pertaining to cold starting and various idling speeds. Also, different approaches have been investigated to improve the signal detection under these conditions.

Three-Dimensional Computational Fluid Dynamics Modeling and Validation of Ion Current Sensor in a Gen-Set Diesel Engine Using Chemical Kinetic Mechanism

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Tamer Badawy ◽  
Naeim Henein
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Low Cost ◽  
Combustion Process ◽  
Chemical Kinetic ◽  
Operating Conditions ◽  
Ion Current ◽  
Design Parameters ◽  
Current Signal ◽  
Dynamics Modeling

Ion current sensing is a low-cost technology that can provide a real-time feedback for the in-cylinder combustion process. The ion current signal depends on several design parameters of the sensing probe in addition to the operating conditions of the engine. To experimentally determine the effect of each of these parameters on the ion current signal, it requires modifications in the engine which would be costly and time consuming. A 3D computational fluid dynamics (CFD) model, coupled with a chemical kinetic solver, was developed to calculate the mole fraction of the ionized species formed in different zones in the fuel spray. A new approach of defining a number of virtual ion sensing probes was introduced to the model to determine the influence of sensor design and location relative to the spray axis on the signal characteristics. The contribution of the premixed and the mixing-diffusion controlled combustion was investigated. In addition, the crank angle resolved evolution of key ionization species produced during the combustion process was also compared at different engine operating conditions.

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