Grantee Research Project Results
Final Report: Portable Emissions Testing System
EPA Contract Number: 68D00227Title: Portable Emissions Testing System
Investigators: May, David F.
Small Business: Analytical Engineering Inc.
EPA Contact:
Phase: I
Project Period: September 1, 2000 through March 1, 2001
Project Amount: $69,987
RFA: Small Business Innovation Research (SBIR) - Phase I (2000) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , SBIR - Air Pollution , Small Business Innovation Research (SBIR)
Description:
This project initiated the development of a prototype, hand held, totally self-contained system for measurement of gaseous emissions from practically any internal combustion engine. Based on the performance of laboratory grade instrumentation, the 40 pound package provides 1 second timeslice sampling frequency and 1 ppm precision for gases of interest. The system will operate with a real-time observer (in a laptop manner) or can be left to operate on the vehicle autonomously. Data is stored in the system computer such that it can be monitored instantaneously by the operator or reviewed at a later time.A key requirement for the project was the successful development of a vibration and thermal gradient tolerant interferometer and optical gas cell combination. To address this need, the project was initially concentrated on the fundamental design of a very robust and mechanically stable interferometer platform. The primary work for this development program included the design, development and prototype generation for subcomponents including an interferometer, multireflection high temperature gas cell, system optics, rechargeable battery pack, housing, communications systems, computer algorithms, optical molecular gas mixture quantification and exhaust mass flow. At the current culmination of this Phase I effort, all subcomponent prototypes and code have been developed. The prototype system utilizes a radically new exhaust mass flow measurement system that provides excellent correlation to laboratory measurements.
The system is designed for use with diesel, gasoline or turbine engine applications. The exhaust sampling probe is designed to provide ease of installation, non-intrusiveness for the engine/exhaust system and provides accurate instantaneous exhaust mass flow. With this information, mass, fuel and brake specific emissions measurements can be measured directly.
Summary/Accomplishments (Outputs/Outcomes):
This Phase I project has resulted in the design and development of the major components and assemblies needed for a portable FTIR based mobile emissions measurement system. This very successful research focused primarily on the design and iterative development of a robust, lightweight and very small interferometer. Currently, the project has generated two distinctly different prototype interferometers, an integral multi-reflection gas cell, a revolutionary exhaust mass flow measurement system and a state-of-the-art enclosure system that includes global positioning, cellular modem communications and a high power density rechargeable power pack. A portion of the effort focused on the development of gaseous analysis strategies and algorithms. Laboratory methods were developed for porting into the mobile system that include chip level code for FFTs, phase correction, apodization functions and statistical treatment of spectral data for complex mixture interspecie discrimination, improved quantification in complex mixtures and multicomponent analysis of complex gas mixtures.A key component to the success of this technology is the exhaust mass flow measurement. A parallel effort progressed through the Phase I project which resulted in the development of a highly effective in-situ exhaust mass flow measurement module. This easily removable module, which resides inside the exhaust pipe of practically any type of vehicle or stationary power plant utilizes a revolutionary process through which the hot, particulate laden exhaust gas mass flow is measured without fouling or sensitivity to thermal or density heterogeneity or pulsations. The design also allows for ease of installation on a variety of geometrical pipe configurations and sizes. This single innovation has alone generated several contacts interested in acquiring units. With the measurement of total instantaneous exhaust mass flow and carbon balance calculations from the FTIR based CO, CO2 and hydrocarbon measurements, fuel consumption can be determined. Through novel statistical treatments of these data with NO and NO2 measurements, instantaneous torque and horsepower predictions are made with astonishing accuracy. This revolutionary predictive capability results in the ability to determine brake specific emissions on mobile platforms without relying on a direct, mechanical torque and engine speed measurement - therefore greatly improving installation times, cross-platform compatibility and non-intrusiveness.
Conclusions:
The work in Phase I has resulted in the clear determination that a mobile FTIR based analyzer is feasible, and practical, for data collection. Work to further package and enhance the system in Phase II will result in a very useful tool for the accurate quantification of practically any optically active gas present in diesel, gasoline, turbine or furnace based emission sources. With the ability to combine 1 second timeslice multi-gas measurements with highly accurate instantaneous exhaust mass flow and crankshaft power predictions, the prospect for achieving on-vehicle brake specific emissions measurements for regulated gaseous emissions is realized. This technology will greatly influence the future processes through which emissions regulations are enacted, evaluated and enforced.The combination of independent operation, ease of installation, and durability, along with cellular download capability, promises to lower the cost of emissions information gathering to an unprecedented level. This will, for the first time, allow cost effective database establishment in reasonable time frames.
Supplemental Keywords:
Inspection and maintenance, On-Vehicle emissions measurements, Non-Road emissions modeling, Non-intrusive on-vehicle mass airflow measurement., RFA, Scientific Discipline, Air, Toxics, Ecosystem Protection/Environmental Exposure & Risk, air toxics, Chemistry, HAPS, Monitoring/Modeling, Environmental Monitoring, tropospheric ozone, Environmental Engineering, Engineering, chromatography, ambient air quality, Nitrogen Oxides, Field Fourier Infrared (FT-IR), stratospheric ozone, environmental measurement, continuous measurement, real time, air pollutants, hydrocarbon, field portable monitoring, nitrogen dioxide (NO2), ambient air, gas chromatography, ambient monitoring, air sampling, field monitoring, analytical chemistry, portable device, FTIR, portable detection system, measurement, continuous emissions monitoring, hydrocarbons, field detection, portable chemical analyzer, aerosol sampling, nitrogen oxides (Nox), field measurements, measurement methods , aerosol analyzers, atmospheric chemistryThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.