Study of Combustion Behavior and Combustion Stability of HCCI-DI Combustion for a Wide Operating Range using a Low Cost Novel Experimental Technique

2014 ◽  
Author(s):  
Pranab Das ◽  
PMV Subbarao ◽  
JP Subrahmanyam
Keyword(s):  
Experimental Technique ◽  
Low Cost ◽  
Combustion Stability ◽  
Operating Range ◽  
Combustion Behavior ◽  
Wide Operating

scholarly journals Dynamic equivalent modeling for power converter based on LSTM neural network in wide operating range

2021 ◽  
Vol 7 ◽  
pp. 477-484
Author(s):  
Yunlu Li ◽  
Guiqing Ma ◽  
Junyou Yang ◽  
Haixin Wang ◽  
Jiawei Feng ◽  
...  
Keyword(s):  
Neural Network ◽  
Power Converter ◽  
Operating Range ◽  
Dynamic Equivalent ◽  
Wide Operating

Methods to Improve Combustion Stability, Efficiency, and Power Density of a Small, Port-Injected, Spark-Ignited, Two-Stroke Natural Gas Engine

2017 ◽  
Author(s):  
Derek Johnson ◽  
Mahdi Darzi ◽  
Chris Ulishney ◽  
Mehar Bade ◽  
Nima Zamani
Keyword(s):  
Natural Gas ◽  
Power Density ◽  
Low Cost ◽  
Exhaust System ◽  
Combustion Stability ◽  
Liquid Fuels ◽  
Delivery Ratio ◽  
Resonance Theory ◽  
Indicated Mean Effective Pressure ◽  
Exhaust Systems

Two-stroke engines are often used for their low cost, simplicity, and power density. However, these engines suffer efficiency penalties due to fuel short-circuiting. Increasing power density has previously been an area of focus for performance two-stroke engines — such as in dirt bikes. Smaller-displacement engines have also been used to power remote controlled cars, boats, and aircraft. These engines typically rely on gasoline or higher-octane liquid fuels. However, natural gas is an inherently knock-resistant fuel and small natural gas engines and generators could see increased market penetration. Power generators typically operate at a fixed frequency with varied load, which can take advantage of intake and exhaust system tuning. In addition, stationary engines may not be subject to size restrictions of optimal intake and exhaust systems. This paper examines methods to improve combustion stability, efficiency, and power density of a 29cc air-cooled two-stroke engine converted to operate on natural gas. Initial conversion showed significant penalties on delivery ratio, which lowered power density and efficiency. To overcome these issues a tuned intake pipe, two exhaust resonators, and a combustion dome were designed and tested. The engine was operated at 5400 RPM and fueling was adjusted to yield maximum brake-torque (MBT). All tests were conducted under wide-open throttle conditions. The intake and exhaust systems were designed based on Helmholtz resonance theory and empirical data. The engine utilized a two-piece cylinder head with removable combustion dome. The combustion dome was modified for optimal compression ratio while decreasing squish area and volume. With all designs incorporated, power increased from 0.22 kW to 1.07 kW — a factor of 4.86. Efficiency also increased from 7% to 12%. In addition to these performance gains, the coefficient of variation (COV) of indicated mean effective pressure (IMEP) decreased from just above 11% to less than 4%.

Steam Injected Gas Turbine (STIG) for Load Flexible CHP: Aspects of Dynamic Behaviour, Control and Water Recovery

2019 ◽  
Author(s):  
Thorsten Lutsch ◽  
Uwe Gampe ◽  
Guntram Buchheim
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Power Plants ◽  
Operating Cost ◽  
Combined Cycle ◽  
System Response ◽  
Water Recovery ◽  
Operating Range ◽  
Demand Fluctuations ◽  
Wide Operating

Abstract Industrial combined heat and power (CHP) plants are often faced with highly variable demand of heat and power. Demand fluctuations up to 50% of nominal load are not uncommonly. The cost and revenue situation in the energy market represents a challenge, also for cogeneration of heat and power (CHP). More frequent and rapid load changes and a wide operating range are required for economic operation of industrial power plants. Maintaining pressure in steam network is commonly done directly by a condensation steam turbine in a combined cycle or indirectly by load changes of the gas turbine in a gas turbine and heat recovery steam generator arrangement. Both result in a change of the electric output of the plant. However, operating cost of a steam turbine are higher than a single gas turbine. The steam injected gas turbine (STIG) cycle with water recovery is a beneficial alternative. It provides an equivalent degree of freedom of power and heat generation. High process efficiency is achieved over a wide operating range. Although STIG is a proven technology, it is not yet widespread. The emphasis of this paper is placed on modeling the system behavior, process control and experiences in water recovery. A dynamic simulation model, based on OpenModelica, has been developed. It provides relevant information on system response for fluctuating steam injection and helps to optimize instrumentation and control. Considerable experience has been gained on water recovery with respect to condensate quality, optimum water treatment architecture and water recovery rate, which is also presented.

Multilayer structured AgNW/WPU-MXene fiber strain sensors with ultrahigh sensitivity and a wide operating range for wearable monitoring and healthcare

2019 ◽  
Vol 7 (26) ◽  
pp. 15913-15923 ◽  
Author(s):  
Jun-Hong Pu ◽  
Xing Zhao ◽  
Xiang-Jun Zha ◽  
Lu Bai ◽  
Kai Ke ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Strain Sensors ◽  
Operating Range ◽  
Highly Sensitive ◽  
Ultrahigh Sensitivity ◽  
Stretchable Sensors ◽  
Wide Operating

Integrating slippage and crack propagation points in a new direction towards highly sensitive and stretchable sensors for wearable healthcare.

A Low-Cost Electronic Method for Measuring Thyristor Convertor Output

1984 ◽  
Vol 21 (1) ◽  
pp. 75-83
Author(s):  
S. K. Tso ◽  
P. T. Ho
Keyword(s):  
Feedback Control ◽  
Low Cost ◽  
Design Concept ◽  
Control Applications ◽  
Operating Range ◽  
Electronic Method ◽  
And Performance

A low-cost opto-electronic method of measuring convertor output currents is proposed serving to overcome the inherent non-linearity of the simple opto-coupler. The design concept and performance of a laboratory-built transducer are described. Over the full operating range much reduced distortion is achieved. The method is useful for feedback control applications.

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