PCME’s involvement with the Power generation industry over many years has led to the development of a range of unique solutions for in-stack measurement of particulate concentration. PCME provide a wide range of approved (TUV and MCERTS) technologies to measure particulate concentration under the varying conditions found in different power generation plant, to facilitate legislative compliance, and also to support ISO 14000 objectives and save operational costs by reducing filter maintenance requirements and process downtime. From this experience, PCME understand the particulate monitoring challenges facing Power Plant operators, including:
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The differing characteristics of combustion emissions and fugitive emissions (eg from fuel pulverising plant), and the most suitable application of corresponding techniques and technologies for low-maintenance particulate monitoring instruments in these differing process conditions
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Meeting or exceeding regulatory requirements such as the ‘Large Combustion Plant Directive’ and supporting standards EN 14181 and EN 13284-2 in Europe, or PS-1 and PS-11 for PM CEMs in the USA, whilst maintaining low cost of ownership and reduced maintenance requirements
A broad range of emissions abatement plant is in use for coal, gas, oil and biomass fired power plant worldwide, in particular electrostatic precipitators, fabric baghouses, cyclones, and a variety of wet scrubbers such as venturi scrubbers and moving-bed scrubbers. Recognising that there is no single measurement technology to best suit all conditions, PCME offer a range of technologies and instruments which are specified for each application in close consultation with PCME, to provide unrivalled performance and quality data for legislative compliance and also to facilitate filter and process optimisation.
Coal Fired Power Plant
Sources of particulate emissions include coal milling plant, where fugitive emissions from the pulverising process are typically collected by means of fabric baghouse filters. As the fugitive pulverised coal dust is fed back into the process, gains in process efficiency can be made by monitoring abatement plant performance to maximise efficiency and minimise fuel loss.
Boiler plant is subject to strict emission controls, where electrostatic precipitators are most commonly used to abate particulates formed via gas phase combustion or pyrolysis, such as soot and fly ash, including silicon and calcium oxides, polycyclic aromatic hydrocarbons and various toxic metallic compounds. Flue gas desulphurisation via a variety of wet scrubbing systems can present problems for many particulate emissions monitoring systems, due to the condensing and corrosive nature of the flue gas. The PCME STACK 181 WS offers a solution for successfully measuring particulate concentration in wet flue gas and after FDG plant.
Gas & Oil Fired Power Plant
The combustion of liquid fuels such as heavy fuel oil is also a source of particulate emissions, although to a lesser extent than coal, and is even less significant in the case of gas fired boilers. However with gas fired power plant, particulate emissions rise significantly when running on fuel oils during start-up or under abnormal conditions. Gas and oil fired power plant therefore require increased sensitivity and high resolution from particulate monitoring systems, with the capability to accurately measure very low particulate concentrations.
Gas Turbines
Modern gas turbines require conditioned inlet air to ensure high performance and minimised maintenance, and to preventing fouling, corrosion and erosion. This is typically achieved with a combination of bagfilters and high efficiency particulate air (HEPA) filters, where filter performance is critical for the peak performance of the turbine. By monitoring particulate concentration in the inter-space between primary and secondary filters for gas turbine inlet air, preventative maintenance measures can be undertaken before the secondary HEPA filter is blocked or damaged, ultimately reducing costs and reducing process down-time.
Biomass Power Plant
Biomass fired power plant emissions are subject to a range of regulatory controls including Local Authority, IPPC and WID schemes (UK & Europe) depending on the scale of power generation and the type of biomass fuel in use. Cyclone filters after smaller biomass boilers and baghouse filters for larger biomass power plant, particularly when ceramic filters are in use, represent a significant operating cost where managing the service life of individual filter elements through filter performance monitoring can provide a considerable reduction in costs. In addition, the ability to monitor individual rows and compartments in large multi-chamber baghouses allows the identification and location of individual filter elements with reduced performance before gross failure occurs. This provides plant operators with data for improved maintenance planning with a reduction in unplanned process intervention and down-time, and minimised emission limit excursion events.
Sufficient minimum detection level for highly abated emissions:
PCME’s ElectroDynamic™ Probe Electrification technology has a minimum detection level (0.1mg/m3) suitable for highly abated emissions, such as those found from oil & gas fired power plant, including QAL1 approved instruments with certification range 0-15mg/m3 for Emission Limit Values as low as 10mg/m3. ProScatter™ Forward Scatter instruments such as PCME QAL 181 are suitable for lower concentrations of <0.1mg/m3, and are also certified to the most demanding European (MCERTS and TUV) and US EPA (PS-11) standards. For monitoring emissions after electrostatic precipitators, PCME’s range of DynamicOpacity™ Ratiometric Opacity instruments are also available with TUV performance approvals.
Range of Technologies:
PCME recognise that differing ambient conditions and process applications require different technologies to ensure maximised system reliability, to provide the most accurate emissions measurement, and to provide operators with data that facilitates process and arrestment plant management for reduced costs and maximised efficiency. Selecting the best technology for an application can mean considerably reduced maintenance and servicing requirements.
For electrostatic precipitator abatement plant, PCME offer a range of DynamicOpacity™ Ratiometric Opacity instruments, which require significantly reduced maintenance compared to typical Opacity instruments. PCME’s DynamicOpacity™ technology also operates with heavy lens contamination of up to 90%, and the instrument is not damaged in the event of air purge failure. For PS-11 (US) and EN 14181 (Europe) compliance for power plant, the PCME QAL 181 using unique ProScatter™ Light Scatter technology offers high sensitivity (minimum detection limit <0.05mg/m3.) and rugged operation with extensive quality assurance and audit features to meet or often exceed regulatory requirements. Bagfilter arrestment plant can be monitored by a networked system of ElectroDynamic™ Probe Electrification instruments, certified to TUV and MCERTS performance standards with patented features for high performance under a wide range of process conditions.
The PCME STACK 181 WS is suitable for measuring particulate emissions from wet scrubbers and other processes where the flue gas falls below the dew point (cold stack conditions) or has water droplet presence. The instrument is able to monitor a saturated flue gas which is critical for the application of monitoring emissions from coal fired power plant using wet flue gas desulphurisation (FDG), while meeting the requirements of PS-11 (US) and EN 14181 (Europe).
Quality Assurance:
Strict compliance programs and more rigidly enforced emission limits within the power generation industry mean that operators require an increased level of quality assurance and complete confidence in their emissions monitoring systems to operate correctly and also minimise emission limit excursion events. PCME offer systems approved to the latest MCERTS & TUV standards, with manual or automated zero and span / reference drift checks for ongoing quality assurance, and other system self-checks such as short circuit, probe contamination and network communication checks to provide confidence in data integrity and to facilitate predictive maintenance scheduling.
High Temperature and Explosive Atmosphere Operation:
PCME instruments include medium and high temperature options up to 800°C, and instruments certified to Category 1, 2 and 3 for ATEX and IECEx applications. High grade ceramics combined with heat shields and heat sinks allow the sensors to operate normally and reliably under temperatures far in excess of standard type sensors.
Network Integration:
Power plant typically requires instrumentation across several emissions sources. PCME sensors can be networked into one central control unit, integrated with existing plant DCS/SCADA systems, and provide Ethernet connectivity for plant-wide LAN integration.
