Further thermal efficiency increase of the Diesel combustion for commercial engines

2017 ◽  
pp. 575-589
Author(s):  
Gernot Graf ◽  
Hans Seitz ◽  
Helmut Theißl ◽  
Alexander Machold
Keyword(s):  
Thermal Efficiency ◽  
Diesel Combustion ◽  
Efficiency Increase

Flow Insulation Characteristics of Combined Two Cordierite Alumina Porous Plates with Free Space

2017 ◽  
Vol 889 ◽  
pp. 275-281
Author(s):  
Preecha Khantikomol ◽  
Maitree Polsongkram
Keyword(s):  
Fluid Flow ◽  
Air Temperature ◽  
Thermal Efficiency ◽  
Free Space ◽  
Porous Plate ◽  
Temperature Drop ◽  
Fluid Temperature ◽  
Air Flow Rate ◽  
Efficiency Increase ◽  
Flow Through

Flow insulator is the material which having fluid flow through itself resulting to the fluid temperature difference between the upstream and downstream regions. The flow insulation characteristics of combined two cordierite alumina (Cr-Al) porous plates with 2 mm free space was investigated experimentally. The results indicated the air temperature drop across the flow insulator and the thermal efficiency increase with the inlet air temperature and decrease with increasing air flow rate. The higher PPI porous plate placing upstream layer resulted in increasing the thermal efficiency of the flow insulator significantly.

Experimental Comparison of GCI and Diesel Combustion in a Medium-Duty Opposed-Piston Engine

2018 ◽  
Author(s):  
Reed Hanson ◽  
Ashwin Salvi ◽  
Fabien Redon ◽  
Gerhard Regner
Keyword(s):  
Thermal Efficiency ◽  
Combustion Efficiency ◽  
Experimental Comparison ◽  
Diesel Combustion ◽  
Compression Ignition ◽  
Piston Engine ◽  
Load Range ◽  
Combustion Performance ◽  
Poppet Valve

The Achates Power Inc. (API) Opposed Piston (OP) Engine architecture provides fundamental advantages that increase thermal efficiency over current poppet valve 4 stroke engines. In this paper, combustion performance of diesel and gasoline compression ignition (GCI) combustion in a medium duty, OP engine are shown. By using GCI, NOx and/or soot reductions can be seen compared to diesel combustion at similar or increased thermal efficiencies. The results also show that high combustion efficiency can be achieved with GCI combustion with acceptable noise and stability over the same load range as diesel combustion in an OP engine.

Laser thermal efficiency increase by means of fast acousto-optic beam scanning

2009 ◽  
Author(s):  
Sergey Antonov ◽  
Valery Proklov ◽  
Alexander Vainer ◽  
Arseniy Yunusov ◽  
Yuri Rezvov
Keyword(s):  
Thermal Efficiency ◽  
Beam Scanning ◽  
Efficiency Increase

Thermal Efficiency Improvements with Split Primary Fuel Injections in Semi-Premixed Diesel Combustion with Multi-Peak Shaped Heat Release

2019 ◽  
Author(s):  
Kazuki Inaba ◽  
Yosuke Masuko ◽  
Yanhe Zhang ◽  
Yoshimitsu Kobashi ◽  
Gen shibata ◽  
...  
Keyword(s):  
Heat Release ◽  
Thermal Efficiency ◽  
Diesel Combustion

Improvements in Thermal Efficiency of Premixed Diesel Combustion with Low Distillation Temperature Fuels

2013 ◽  
Author(s):  
Qian Xiong ◽  
Kazuki Inaba ◽  
Tatstunori Obe ◽  
Hideyuki Ogawa ◽  
Gen Shibata
Keyword(s):  
Thermal Efficiency ◽  
Diesel Combustion ◽  
Distillation Temperature

Mechanism of thermal efficiency improvement in twin shaped semi-premixed diesel combustion

2021 ◽  
pp. 146808742110264
Author(s):  
Kazuki Inaba ◽  
Yanhe Zhang ◽  
Yoshimitsu Kobashi ◽  
Gen Shibata ◽  
Hideyuki Ogawa
Keyword(s):  
Heat Release ◽  
Thermal Efficiency ◽  
Gas Flow ◽  
Fuel Injection ◽  
Premixed Combustion ◽  
Combustion Noise ◽  
Diesel Combustion ◽  
Combustion Mode ◽  
Secondary Stage ◽  
Combustion Phase

Improvements of the thermal efficiency in twin shaped semi-premixed diesel combustion mode with premixed combustion in the primary stage and spray diffusive combustion in the secondary stage with multi-stage fuel injection were investigated with experiments and 3D-CFD analysis. For a better understanding of the advantages of this combustion mode, the results were compared with conventional diesel combustion modes, mainly consisting of diffusive combustion. The semi-premixed mode has a higher thermal efficiency than the conventional mode at both the low and medium load conditions examined here. The heat release in the semi-premixed mode is more concentrated at the top dead center, resulting in a significant reduction in the exhaust loss. The increase in the cooling loss is suppressed to a level similar to the conventional mode. In the conventional mode the rate of heat release becomes more rapid and the combustion noise increases with advances in the combustion phase as the premixed combustion with pilot and pre injections and the diffusive combustion with the main combustion occurs simultaneously. In the semi-premixed mode, the premixed combustion with pilot and primary injections and the diffusive combustion with the secondary injection occurs separately in different phases, maintaining a gentler heat release with advances in the combustion phase. The mechanism of the cooling loss suppression with the semi-premixed mode at low load was investigated with 3D-CFD. In the semi-premixed mode, there is a reduction in the gas flow and quantity of the combustion gas near the piston wall due to the suppression of spray penetration and splitting of the injection, resulting in a smaller heat flux.

scholarly journals Numerical Modelling of a Concentrating Photovoltaic Thermal Collector

2019 ◽  
Vol 16 (2) ◽  
pp. 6482-6501
Author(s):  
M. Valizadeh ◽  
F. Sarhaddi ◽  
F. Sobhnamayan
Keyword(s):  
Ambient Temperature ◽  
Thermal Efficiency ◽  
Fluid Velocity ◽  
Incident Beam ◽  
Inlet Temperature ◽  
Beam Radiation ◽  
Electrical Efficiency ◽  
Current Voltage ◽  
Diameter Pipe ◽  
Efficiency Increase

In this paper, the performance evaluation of a concentrating photovoltaic thermal (CPVT) collector is carried out. By writing energy, balance for the various components of CPVT collector, a set of nonlinear equations is obtained to calculate the temperature of different parts of the system. The electrical parameters of the CPVT collector are calculated by the four-parameter model of current-voltage. The simulation results of the present study are in good accordance with the previous studies data. The results show that with the fluid velocity increase from 0.08 to 0.43 m/s, the electrical efficiency and thermal efficiency increase by 1.05% and 2.2%, respectively. The thermal efficiency is enhanced by 9.4% as the receiver width is increased from 0.06 to 0.2 m. With the increase of diameter pipe from 0.017 to 0.06 m an increase of 2.75% and 3.9% is observed in the thermal and electrical efficiencies, respectively. The thermal efficiency has an ascending/descending trend with the increase of collector length. The increase of fluid inlet temperature from 273.15 to 363.15 K reduces the thermal and electrical efficiencies by 7.3% and 4.05%, respectively. The increase of the incident beam radiation from 300 to 1000 W/m2 enhances the electrical efficiency by 4%, while the thermal efficiency has an ascending/descending trend. The ambient temperature increase causes an increase of 5.1% in thermal efficiency. The effect of receiver width and ambient temperature on electrical efficiency is negligible.

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