Continental Controls Corporation (CCC) has introduced a new ultra-low emissions system that offers automatic compliance without the normally required operator intervention.
The key to our breakthrough for this system is the addition of a NOx sensor downstream of the non-selective catalytic converter (NSCR). This NOx sensor provides feedback and confirmation that the engine is running well, the catalyst is working correctly and the entire emissions control system is working as it should.
As the NSCR ages and the oxygen sensor drifts over time, adjustments to the air fuel ratio (AFR) system will be made automatically based on input from the NOx sensor. This is a quantum step forward in controlling emissions for natural gas engines over an extended period of time.
Other manufacturers have achieved this level of compliance for a short time but nobody has developed a system like this that is auto-correcting for changes in ambient conditions, changes in sensors or ageing NSCR that does not require frequent operator intervention.
The concept of using a NOx sensor to maintain the ideal set-point to optimise the emissions reduction from an NSCR catalyst is quite novel and CCC has applied for a patent on the system and method.
NOx sensors have been used to try to minimise NOx from lean-burn engines but this is the first product to use NOx sensor on a rich burn engine with an NSCR catalyst.
CCC has been designing and manufacturing some of the most effective fuel control
products for gas engines and gas turbines for more than 20 years. They have pioneered ideas such as advanced flow control and variable pressure control fuel valves, valves that have integrated AFR controls and even electronic carburettors with integrated support for advanced oxygen sensors.
Even with advanced techniques and technologies, until now it has not been possible to maintain long-term compliance without having an operator test emissions with a portable emissions analyser to determine the optimum AFR to obtain the level of reductions required.
Now, by adding the CCC catalyst monitor with the NOx sensor in the engine exhaust and providing dynamic feedback to the AFR, it is possible to keep the engine in compliance over a much longer time frame.
CCC vice-president Rick Fisher said: “During our field test at Fontana Wholesale Lumber on their Waukesha Engine, we left the engine completely alone for more than three months and we were still at the lowest required levels of both NOx and CO without any operator intervention. We believe that this may be the first time that this has been achieved.”
All of CCC’s emission control valves now use CAN Bus communications, which allows for multiple devices to communicate on the same bus. This puts the fuel valves, the NOx sensor and the Cat Monitor all in constant communication, allowing for some new and unique control architecture.
Cat Monitor logs data related to emissions control and has the ability to report that information back to a central control office via Ethernet TCPIP, cell or satellite modem for remote locations.
CCC is a controls and components manufacturer for gas turbines and reciprocating natural gas engines.