Overview

The use of ammonia is increasing at power plants for both NOx reduction and turbine inlet cooling. The EC-F9-NH₃ electrochemical sensor is excellent for monitoring ammonia at low ppm levels without false trips for either gas sensing application.

In NOx reduction applications, the gas sensors will be placed around the receivers, pumps and injection equipment used in flue gas conditioning. Piping to ductwork and injection nozzles are also potential sources of ammonia leakage. Most equipment will be located outdoors and the special challenges of outdoor sensing, i.e., prevailing winds, temperature and moisture conditions, must be considered. Manning Systems sensors can be equipped with ATMOS technology for outdoor applications.

The EC-F9-NH₃ gas sensor is specific to ammonia and can trip as low as 15 ppm without nuisance alarms. Because there is nothing to actually contain a leak outdoors, it is imperative to monitor and recognize a leak as quickly as possible to eliminate the hazards associated with an ammonia release into the air. Electrochemical technology is designed to recognize and react to a leak while it is still in the low ppm range without responding to the numerous potential interference gases present in the power plant environment, such as sulfur dioxide, hydrogen sulfide, methane, etc.

In turbine inlet cooling applications, ammonia is used as a refrigerant, involving compressor rooms, and sometimes ice building or chilled water heat exchangers. In an enclosed room containing ammonia equipment, recent fire and mechanical codes mandate ammonia-specific sensing for both low and high trip levels. The EC-F9-NH₃ electrochemical sensor is used for low ppm ammonia sensing, and high level detection in the 1-2% range is provided by the IR-NH₃ infrared detector. Typical trip levels for a compressor room are 50/150 ppm and 1-2% (20,000 ppm) ammonia.

If the sensor must be located downstream of an ammonia coil in the turbine inlet, special sensor construction assures that no loose pieces can be released into the inlet.

Related products and technology

All Manning Systems sensors can be monitored by the GM-JR single channel gas monitor or the HA20, HA40 or HA71 multi-channel gas safety systems that provide an individual bargraph display of gas concentration for each channel, plus relay outputs for emergency response and ventilation control. Calibration Gas Kits are always available from Manning Systems to maintain and verify the highest level of total system performance.

The new AirAlert™ 96d multi-channel gas monitoring system adds addressable RS-485 Modbus communication protocol to the broad line of Manning Systems readout/alarm units. A total of 96 gas sensors and relay modules can be linked to a single controller.

Manning Systems offers personal protection portables for the single- and multi-sensor toxic gas detector market. These innovative, low-cost portables are ideal for industrial hygienists, safety managers, petrochemical applications, fire departments, police and emergency responders at risk of exposure to toxic contaminants.