Nitrogen Oxide Sensor to Optimize Dispatchable Distributed Generation Systems
January 21, 2021
Energy Research and Development (500)
Electric Program Investment Charge - EPIC
Ryan Ehlig, Vince McDonell
The increase in intermittent renewable sources has created a need for clean dispatchable generation sources that can quickly generate electricity to meet demand. Dispatchable generation devices include microturbines and reciprocating engines. They can be certified as low emission, but the certification process involves generating at full capacity. Often, only partial capacity generation is needed to meet demand, yet a means to ensure clean operation at partial capacity is needed. This project evaluated the viability of using low-cost automotive sensors for nitrogen oxides (criteria air pollutants typically generated from the combustion process) and oxygen to continuously monitor emissions performance of a 60-kilowatt microturbine generator. In this study, the generator operated over a programmed range of capacity for six months, during which sensors from UniNOx and NTK, two commercial manufacturers, were evaluated for durability and accuracy by comparing their readings to a referee instrument, Horiba PG-350. Results showed that both sensors were robust and did not exhibit significant errors. The NTK sensor proved to be more precise and was thus selected for integration into the 60-kilowatt engine operating system. The project team developed the necessary electronics and control algorithms and modified the engine control software to integrate both. Testing of active control of the engine operation using the sensor information led to a reduction of about 10 percent in nitrogen oxides compared to baseline emissions levels. The project demonstrated that using such sensors to attain performance to minimize emissions is feasible and relatively economical.