31. SENSORS AND
CONTROLS FOR FOSSIL ENERGY POWER GENERATION SYSTEMS
For the foreseeable future, the energy needed to sustain economic growth will continue to come largely from the Nation’s most abundant and lowest cost resource, coal. Maintaining low-cost energy in the face of growing demand and increasing environmental pressures requires new technologies that will enable higher efficiency. The implementation of sensors and advanced controls in power systems can provide valuable methods to improve operational efficiency, reduce emissions, and lower operating costs. These sensors and controls must provide reliable and consistent data, longevity of use, and ease of calibration. However, it has been a challenge to develop sensors and controls that are able to endure the harsh environments associated with advanced power systems. This environment includes high temperatures (800-1500°C), high pressures (500-1000 psi), and corrosion due to abrasive materials. Grant applications are sought only in the following subtopics:
a. Solids Flow Characterization Measurements in High
Temperature, Non-Mechanical Valve Systems—In
advanced fossil fuel power systems, unique transport and fast fluidization flow
regimes create better mixing and, therefore, better efficiency and fuel
consumption. These conditions could be
optimized by improving the measurement of solids flow, as well as particle flow
characteristics. The ability to obtain
these measurements by utilizing
non-mechanical valves (as opposed to the more obtrusive mechanical valves)
would be particularly valuable, especially in coal fired power plants where unburnedhot, burned, spent ash and sorbent are recycled and
combined with feedstock in such transport systems as circulating fluidized beds
(CFB). Such non-mechanical valves also
would be valuable in chemical looping systems to transfer solids between
different reactor vessels. Grant applications are sought for solids flow characterization devices that use
non-mechanical valves and can withstand the harsh environments of coal
fired plants. The environment includes
high temperatures (800-1500°C), high pressure (500-1000 psi), and corrosion due
to high flow rates of abrasive materials and slag. Approaches of interest include:
(1) The development of a
continuous, non-obtrusive, solids-circulation monitoring device – the device
must be suitable for continuous use, minimize any loss of availability of the plant as a result of using
the device, and provide on-line calibration methods
to ensure that feed rates can be controlled with an accuracy of ±5%.
(2) A method to obtain
simultaneous particle velocities and concentrations to enable diagnostic flow regime characterization of the flow structure
over a wide range of flow regimes. The measurement device must provide spatial resolution
at the millimeter length
scale and temporal resolution at the millisecond time scale, be non-intrusive, and be capable of
obtaining full three-dimensional tomographic images over at least a
1-foot diameter, using
techniques such as ultrasound, acoustic, x-ray, or capacitance techniques. On-line quantitative calibration methods are
required over the entire range, from 0.01 to 0.5 solids volume fraction, to
ensure that solids concentrations and velocities can be measured with an
accuracy of ±1%. Devices can be
demonstrated in a cold flow unit.
Questions: Contact Steven Seachman
(steven.seachman@netl.doe.gov)
b. Development of Standard Packaging and Integration of Sensors for On-Line use in Harsh Environments—The high-temperature harsh environment of an advanced power system requires several types of measurements (e.g., temperature, pressure, strain, and gas composition) to be made in order to operate and control the system efficiently. Different sensor probes are required to measure each parameter. While much success has been realized in the area of sensor materials and designs for these environments, very little work has been devoted towards the integration of sensor devices into commercial-scale systems through the use of packaging designed for harsh environments. The lack of a standardized package for micro sensors serves a barrier to the commercial use of these devices. For development efforts, packaging is essential to conduct long term pre-commercial testing. Grant applications are sought for standardized packaging of fiber optic or MEMs-based sensors in high temperature (500-1000oC) and harsh (strongly reducing or oxidizing conditions, particulates, etc.) environments. A robust approach to the packaging of these sensors is desired, in order to enable their ease-of-use and application to on-line sensing for commercial full scale power systems.
Grant applications should develop a detailed approach that focuses on a general sensor type (fiber optic or MEMs) and one or more fossil fuel-based power systems (e.g., coal-fired boiler systems, coal gasification systems, land-based gas/syngas turbines, solid oxide fuel cell power systems). For fiber optic sensors, the approach to packaging may depend on the sensor configuration (e.g., single point measurement, multiple measurements within a fiber bundle, and/or multiple sensors distributed along the length of a single fiber).
Questions: Contact Robie Lewis (robie.lewis@netl.doe.gov)
c. New Approach to Process Control Architecture for Operation of Large Scale Central Power Systems— Grant applications are sought for novel approaches to the control system architecture for large scale central power systems. Approaches of interest should depart from traditional hierarchial control systems and consider emerging approaches for managing a large number of system inputs and outputs, including the use of (1) sensor networks with computing, communication, and logic capability; and (2) high performance process models for control.
Grant applications should (1) identify a formal approach to the utilization of dense, pervasive, and highly intelligent sensor networks; (2) demonstrate a predictive capability in a decentralized platform; and (3) describe the potential advantages and disadvantages of the proposed approach. Approaches based on PID (Proportional-Integral-Derivative) control are not of interest and will be declined.
Questions: Contact Susan Maley (susan.maley@netl.doe.gov)
References:
Subtopic a: Solids Flow Characterization
Measurements in High Temperature, Non-Mechanical Valve Systems
Park, J., et al., “The control of bed height and solids
circulation rate in the standpipe of a cold flow circulating fluidized bed.”
2005 (full text available at: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TH9-4FNDS2X-1&_user=2638189&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000058399&_version=1&_urlVersion=0&_userid=2638189&md5=4f5fdfc63b3298da7fa6981430d8005f)
Lui, S., Electrical capacitance tomography for gas–solids flow measurement for
circulating fluidized beds (full text available at http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V38-4G3KBTC-1&_user=2638189&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000058399&_version=1&_urlVersion=0&_userid=2638189&md5=3979fd2220f97404d81486154b7f3be3)
Descriptions of the fossil fuel-based power systems can be found at www.netl.doe.gov and descriptions of a select number of sensor development projects are also listed on NETL’s website.
Subtopic b: Development of Standard Packaging and
Integration of Sensors for Industrial on-line use in Harsh Environments
Descriptions of the fossil fuel-based power systems can be found at www.netl.doe.gov and descriptions of a select number of sensor development projects are also listed on NETL’s website.
Subtopic c: New Approach to Process Control Architecture for Operation of Large Scale Central Power Systems
Please refer to www.netl.doe.gov for a description of the advanced power plants currently under development.