Areas of Research Expertise: Engines Emissions and Efficiency
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Background: Engines & Energy Conversion Laboratory
The Engines & Energy Conversion Laboratory (EECL) is a unique research/education program housed in the Department of Mechanical Engineering. The laboratory was established in the Old Fort Collins Power Plant in June 1992. In the years since then the laboratory has grown to become one of the largest and most influential engines research programs in the United States. The EECL is widely recognized as an international leader in the fields of large gas engines for power generation and compression, small 2-stroke cycle engines for use in developing countries, alternative fuels for automobiles, computational fluid dynamic (CFD) modeling of engines, and optical combustion diagnostics. The Department has invested in the laboratory through the recent hires of two new faculty members who have established new EECL programs in diesel engines, laser diagnostics, and plasma applications in engines.


 


prechamber
Imaging of a prechamber flame jet in a GMV-4TF engine at 11° ATDC. Prechamber nozzle is at upper left

Ignition in Industrial Engines - back to top

There are two primary areas of ignition research, laser ignition and precombustion chamber ignition. High energy pulsed lasers are being investigated as a means to ignite very lean mixtures in high BMEP engines. Most agree that fiber delivery of the laser light is an enabling technology for this ignition approach. In June of 2005 the CSU research team became the first in the world to run an engine cylinder using a pulsed laser ignition system that employed hollow core fibers to deliver the laser light. Precombustion chambers are an established ignition technology for large industrial natural gas engines. However, to meet more stringent emissions regulations prechamber performance must be improved and NOx generation in the prechamber must be mitigated. As part of this effort the CSU EECL has developed an optically accessible head for our GMV-4TF engine for evaluation of new prechamber concepts. Other diagnostic tools being employed are fast sampling of prechamber gas and spectroscopic analysis of combustion emitted light.


Exhaust Aftertreatment for Industrial Engines - back to top

The primary areas of emphasis in exhaust aftertreatment at this time are nonthermal plasmas and Selective Catalytic Reduction (SCR). Both are targeted for lean burn applications. In the area of nonthermal plasmas a number of different approaches are being investigated. These include different plasma sources as well as various methods for treating the exhaust. On-going testing involves the marrying of nonthermal plasma and SCR technology by creating a nonthermal plasma from the ammonia reductant stream in a standard SCR configuration. In conventional SCR research the CSU EECL is in the early stages of a multi-year program. This research focuses on large bore two-stroke compressor engines. In this work a slipstream SCR research system is being built on the GMV-4TF engine. This system is designed to enable investigation of state-of-the-art SCR technology, such as pre- and post-oxidation catalysts, hydrolysis catalysts, different reductant types, reductant mixing effects, space velocity, catalyst temperature, and different SCR catalyst formulations.


CAT engine
Caterpillar G3516C 50 Hz natural gas engine.

Engines for Distributed Power Generation - back to top

In August of 2005 a 1.7 MW Caterpillar 3516 natural gas engine for distributed power generation was installed at the CSU EECL. The engine is used primarily for engine development work. Current work includes experimental evaluation of ion sensing systems and advanced spark plug technology. There is also on-going electrical grid simulation work. This project involves the installation of various small scale distributed generation sources at the EECL, which include a wind turbine simulator, reciprocating engines, a gas turbine, and a fuel cell. Research will be performed on the stability of the electrical grid as various combinations of these sources are operated through a range of conditions.


Waukesha engine
Waukesha VGF 18 liter engine

Friction Reduction - back to top

The goal of this research is to reduce parasitic losses of natural gas reciprocating engines by reducing piston/ring assemply friction without introducing major adverse effects. The work is being performed on a 6 cylinder Waukesha VGF 18 liter engine. Highly precise measurements of FMEP and oil consumption are recorded for various ring pack designs and configurations. Test results are compared with friction modeling performed at MIT.

 


Gas Composition - back to top

Gas fueled engines are typically designed to operate on gaseous fuel composition within a small "window" bounded by methane number and Wobbe index. When the gas composition falls outside this "window" the engine can experience problems with the emissions compliance, detonation, fuel system capacity, and engine control. LNG imports, aging natural gas wells, biogas and synthetic gas production, landfill and digester gas supply, and other factors have brought gas composition issues to the forefront. The CSU EECL is performing gas composition research and developing capabilities to expand this research activity. We have installed infrastructure to perform propane blending with natural gas to increase the methane number of the gaseous fuel delivered to test engines. This capability is being used for development of knock detection and control technologies. There are plans to add CO2 and N2 blending to simulate landfill gas and add to methane blending to allow full control of methane number.


4045H Deere engine
John Deere 4045H used for biogas testing

Biogas - back to top

A 4.5 Liter 175 HP John Deere 4045 Engine was installed in 2005 at the CSU EECL for biogas research. Specifically, "producer gas" from the gasification of wood is being studied utilizing a Community Power Corporation 15kW Gasification unit. The fuel is ignited using diesel pilot fuel injection. The research focuses on three areas: (1) implementing common rail diesel pilot injection, (2) optimizing timing and duration of pilot fuel injection, and (3) using WAVE modeling for turbocharge sizing.

 

 

 


Stationary Source Technologies - back to top

The EECL specializes in the study of emissions formation in internal combustion engines. The lab has particular expertise in emissions from large stationary engines, small two-stroke engines, and engines operating on alternative fuels. The laboratory has developed emissions control technologies for all of these applications.

The EECL conducts its research in several ways:

  • Basic science studies of chemical kinetics, combustion, and pollution formation.
  • Advanced computation using computational fluid dynamics to examine mixture formation and predict emissions from internal combustion engines; engine simulations to investigate air flow phenomena, engine performance trends, and component design.
  • Advanced optical diagnostics to study air/fuel mixing, combustion, and emissions formation. Tthe EECL houses the world's largest optical engine, complete with a wide variety of sophisticated laser diagnostics.
  • Engine testing. The EECL has the most extensive engine testing capabilities of any universtiy in North America, with capabilities for testing engines of over 150,000 pounds and producing over 2500 horsepower.

Emission measurement capabilities include:

  • 5-Gas Emissions Analysis: chemiluminescence measurement of NOx, flame ionization detection of hydrocarbons, paramagnetic detection of oxygen, non-dispersive infrared detection of CO and CO2.
  • Fourier Transform Infrared Analysis: speciated measurement of HC through C4, speciated measurement of NOx compounds (NO, NO2, N2O,N2O5,NH3, etc), SOx compounds, aldehydes (formaldehyde, acetaldehyde, acrolein). New capabilities are being added to allow measurement of BTEX compounds.
  • Gas Chromatograph analysis: primarily for fuel, but also for exhaust hydrocarbon speciation.
  • Cavity Ringdown Spectroscopy: capable of measuring ultra-low concentrations.


PLIF imaging
Comparison of PLIF imaging (left) and CFD results (right) for high pressure fuel injection

Air Pollution Formation and Control - back to top

Large Engine Studies - The EECL has established the world's only university-based facility for conducting experimental research on large engines. The value of this facility is estimated at over $5 million. Recent key accomplishments from this facility include:

  • Large Bore Engine Testbed - Further development/improvement of the "Large Bore Engine Testbed" for conducting research on the very large slow-speed engines (300-400 rpm) used on the nation's natural gas pipeline system, typically 1,000 - 8,500 hp.
  • Industrial Engine Research Facility - Established for conducting research on the large (500 hp - 2300 hp) medium-speed engines (900-1800 rpm) used for distributed power generation and industrial applications.
  • Optical Engine Facility - Established to allow laser-based diagnostics of mixing, combustion and pollution formation phenomena in large engines. This is believed to be the world's largest optical access engine.
  • Computational Fluid Dynamics - Capability established to perform detailed computational studies of mixing, combustion, and pollution formation in internal combustion engines. The CFD results are compared closely with optical imaging to ensure the validity and relevance of the computational work.

High-Pressure Fuel Injection - The EECL pioneered the application of "high pressure fuel injection" for large natural gas engines, with the first publication on the topic in 1998. The technology is now being rapidly commercialized and is credited with allowing simultaneous reduction in emissions and fuel consumption on the US natural gas pipeline system. Research on high-pressure fuel injection includes:

  • Development/documentation of the technology to simultaneously reduce: NOx emissions by 60%-90% HAPs emissions by 25%-40%, fuel consumption by 6%-9%, and greenhouse gas emissions (CO2 and methane) by over 25%.
  • Technical support for commericialization by companies in Colorado, Texas, New York, and Austria.
  • Establishment of a program of advanced optical diagnostics and computational fluid dynamic analysis to further improve the technique.


Laser Diagnostics for Combustion Systems - back to top

Capabilities include planar laser induced fluorescence (PLIF) and laser induced incandescence (LII) for quantitative, temporal and spatial measurements of NO, OH and CH and soot volume fraction. Existing resources in terms of optical and laser equipment include a Nd:YAG pumped optical parametric oscillator (OPO), a second high-power seeded Nd:YAG laser, several optical tables, low-power alignment lasers, beam conditioning and delivery optics, intensified camera, photo-detectors (photo-multipliers, photodiodes), oscilloscopes, timing boxes, computer acquisition systems etc.


Laser spark
Laser spark formation via a hollow core fiber

Laser Ignition - back to top

Laser Ignition is exploring the potential of using focused lasers to replace the spark plugs currently in use in large natural gas engines. This project is a large effort working with DOE, the California Energy Commission, Argonne National Lab, the National Energy Technology Lab, the Oak Ridge National Laboratory and several engine manufacturers. Successful single cylinder tests were performed at the EECL on slow speed and medium speed natural gas engines.