PROGRAM AREA OVERVIEW

31. SENSORS AND CONTROLS FOR EFFICIENCY AND RENEWABLE ENERGY APPLICATIONS

Innovative sensor and control technologies could significantly improve the performance, reliability, and economics of energy use in a variety of applications, including the generation of electricity from renewable energy. The integration of sensors and controls would allow feedback systems to continuously respond to system changes, reducing operations and maintenance costs and mitigating technical risk. For example, fault detection and diagnostics systems that provide early warning of system problems could prevent costly repairs or replacement of equipment in wind turbines and HVAC systems. Likewise, the effective monitoring of process conditions, combined with methods for controlling the process, could enable process optimization or problem mitigation in geothermal power generation, biomass conversion, and automotive combustion. Because these processes often take place under conditions that include high temperatures and corrosive constituents in the process stream, sensors and controls that can work in these harsh environments would significantly contribute to minimizing wasted energy and damage to key equipment. Grant applications are sought only for the following subtopics:

a. Geothermal Two-Phase Flow Instrumentation and Control—The fluid produced from geothermal wells is often a two-phase flow consisting of solids along with non-condensable and corrosive gases. Development of improved two-phase flow monitoring and logging instruments would help reduce the cost of geothermal power, increase the effectiveness of reservoir management, reduce operator risks, and improve the economics of geothermal power production. Such instrumentation must be capable of providing reliable measurements in the high-temperature, physically and chemically aggressive environment of geothermal process streams. Grant applications are sought for the following innovative two-phase monitoring and control equipment: (1) a meter to acquire accurate, real-time measurements of two-phase mass flow at individual producing geothermal well installations – approaches of interest must not involve such established methods as orifice plate, choke flow, and grab sample technologies; (2) instrumentation for accurately sampling and monitoring geothermal steam quality and purity, in order to protect power plants against process upsets – the instrumentation must signal such occurrences and initiate corrective action to mitigate impending damage; (3) a control valve for throttling two-phase geothermal fluids at the well site – the valve must be resistance to erosion, corrosion, and scaling; have throttling ability from 0 to 100% of opening; and have a large, full-opening control valve coefficient, Cv, where Cv is the capacity of a valve in terms of the number of gallons of water per minute that will flow through the valve with a pressure of 1 psi; and (4) a steam quality and flow logging tool for installation in geothermal production wells.

With regard to item (4) above, tool specifications include: outer diameter less than 2 inches; temperature rating of 250°C without the need for heat-shielding; temperature rating of 350°C for 16 hours with or without heat-shielding (Dewar); pressure rating of 10,000 psi; ability to operate in either memory or real-time mode. The ideal ranges for the measured parameters include: steam quality, 10 to 90%; flow, 0 to 400 tons/hour; pressure, 0 to 10,000 psia; and temperature, 0 to 500°C. Particular consideration will be given to approaches that provide a permanently installed system for monitoring and controlling multi-lateral production values, so as to isolate zones for enhanced well performance.

b. Automotive Sensors, Controls, and Automation—In order to optimize the efficiency, performance, and emissions profile of current and near-term advanced vehicle engines, advances in sensors, controls, and automation are necessary. For example, robust, low-cost sensors for engine-exhaust constituents such as NOx, ammonia, and particulate matter are desired. Also, low-cost sensors for measuring in-cylinder conditions can play an important role in combustion management and control for these engines; these sensors may be either direct or virtual, and may be used to determine when the engine is at the boundary of a particular combustion regime. Although progress has been made in these technologies, commercial devices that meet all of the required performance and cost criteria are not available. Grant applications are sought to develop:

(1) Low-cost, robust sulfur sensors. The purpose of these sensors are to protect two types of systems: first, near-term (2007 – 2010) engine and emission-control systems that use exhaust sulfur traps or other sulfur removal techniques; and, second, the fuel system (which uses, e.g., interlocks), to prevent fuel containing more than 15 PPM sulfur from contacting sulfur-sensitive components.

(2) Broadband fuel sensors that can provide representative chemistry information. The information provided must account for the increasing broad range of chemistries found in heavier fuel sources and for their impact on combustion kinetics, so as to meet high efficiency and low emissions requirements.

(3) A low-cost pressure transducer to enable the detection of cycle-to-cycle variance in peak cylinder pressure, along with the associated crank location of the pressure peak. This transducer would allow on-line, real-time calculation of heat-release rate and other combustion parameters.

(4) Practical, small, cost-effective, and real-time broadband sensors for monitoring engine combustion, exhaust gas, and related parameters needed to control combustion process in an automotive engine. Durable sensors for pressure, temperature or other variables would provide closed-loop control for homogenous charge compression ignition engines. Sensors that provide measurement of exhaust species or intermediates, which may serve as markers of advanced combustion regimes, are of particular interest. Sensors of interest could be installed either within the cylinder or external to it; if installed in the cylinder of an engine, there should be no disruption of the hydrodynamics or thermodynamics of the combustion event.

(5) Practical, durable, and cost effective sensors to monitor exhaust gas species, such as hydrocarbons, oxides of nitrogen, aldehydes, and other compounds created by low temperature combustion regime engines. These would be suitable for on-board diagnostics as well as for feedback loop control systems.

c. HVAC Sensors, Controls, and Automation—New cooling equipment must meet certain efficiency standards when manufactured. However, faulty installation and operating conditions can degrade efficiency. For example, grass clippings from lawn mowing can get sucked into the outside condensing unit coil of a brand new unit and cause the efficiency to degrade for the life of the unit. Although the early warning of problems could prevent unneeded equipment repairs or replacement, there is no easy way to check the efficiency of the system once the equipment is installed. The development of HVAC sensors and controls could allow equipment performance to be measured, and efficiency could be maintained by proper corrective action. Information regarding the equipment being monitored could be communicated over the Internet via modem for remote monitoring in real time by a service company or the owner. Therefore, grant applications are sought to develop: (1) low-cost, remote fault detection and diagnostics systems for HVAC systems, including commercial rooftop and residential systems, that can continuously monitor performance and detect such faults as charge leakage, economizer malfunction, heat exchanger fouling, burner condition, and controls malfunctions; (2) new sensor, electronics, and software technologies that leverage wireless networks, mobile computers, and the Internet to provide user-friendly, low cost systems – for example, intelligent wireless controls, possibly combined with low cost thermal storage, to reduce peak electricity demand from HVAC systems; (3) variable speed motor and drive technologies with low applied costs, using adaptive/fuzzy logic controls to enhance comfort and indoor environmental quality, while reducing energy consumption; (4) modules, for integration with HVAC systems, that can respond to price and peak demand signals; and (5) automated ductwork damper systems with occupancy sensing to improve zone control – with mass production, these FDD (fault detection and diagnosis) systems should add no more than $50-100 to the final consumer cost of a unitary residential HVAC system.

d. Sensors for Industrial Manufacturing Applications—Real-time measurement and control is needed to optimize the performance of a number of industrial processes: petroleum refining and petrochemical manufacturing; the production of bioproducts and biofuels, forest products, aluminum, steel, and glass; metalcasting and mining. The development of new sensing technologies would enable industry to measure critical process and/or product properties such as temperature and pressure profiles and/or chemical compositions and stoichiometry in real time during the production process itself. The sensors and controls must be capable of withstanding the harsh (corrosive, very high or very low temperatures) conditions found in industrial processing and manufacturing. In addition, the measurements must be made in situ, as opposed to the current indirect methods.

Grant applications are sought for the on-line monitoring and control of: (1) reaction conditions and constituent byproduct concentrations in reactors under harsh operating conditions (e.g. extreme pH, high temperature, two or three phase flow, high solids); and (2) biologically compatible conditions on complex slurry streams (e.g. mixtures of biomass sugars in presence of soluble acids, phenolics, and fermentation products/byproducts). Grant applications are also sought for sensor development approaches that use engineered materials solutions, such as molecular scale tailoring, for selectivity and sensitivity; or nanostructured materials/coatings for sensor viability and robustness in harsh environments. Possible applications include but are not limited to the measurement of: (1) temperature and/or composition in cryolite or black liquor; (2) temperatures greater than 600^oC, or less than -40^oC, (3) sulfur compositions less than 50 ppm, (4) pressures greater than 200 atmospheres.

References:

1. Hibara, Hara, & Sakanashi, “Steam Purity of Geothermal Plant,” Geothermal Resource Council Transactions, Vol. 13, 1989. (ISSN 0193-5933) ((For Transactions ordering information, see: http://www.geothermal.org/pubs.html)

2. Roth, K., et al., Energy Consumption Characteristics of Commercial Building HVAC Systems Volume III: Energy Savings Potential, prepared by TIAX, LLC for U.S. Department of Energy, July 2002. (Available at: http://www.eere.energy.gov/buildings/documents/pdfs/hvacvolume3finalreport.pdf)

3. Yashar, D. and Domanski, P., “MEMS Sensors for HVAC&R,” American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Journal, 19(5), May 2004. (ISSN: 0001-2491)

4. Agenda 2020 The Path Forward: An Implementation Plan, Forest Products Industry Technology Roadmap, Washington, DC: American Forest and Paper Association, February 1999. (Available at: http://www.oit.doe.gov/forest/. Toward the center of the page, click on roadmaps, and then click on link under title.)

5. Vision 2020: Reaction Engineering Roadmap, New York: AIChE, Center for Waste Reduction Technologies, 2001. (Available at: http://www.oit.doe.gov/chemicals/pdfs/reaction_roadmap.pdf.)

6. Roadmap for Process Equipment Materials Technology, Materials Technology Institute, October 2003. (Available at: http://www.mti-link.org/members/downloads/MOC%20Roadmap%20Final%20corrected%201-20-04.pdf)

7. Technology Roadmap for the Petroleum Industry, February, 2000. (Available at: http://www.oit.doe.gov/petroleum/pdfs/petroleumroadmap.pdf)

8. Mining Industry Roadmap for Crosscutting Technologies. (Available at: http://www.oit.doe.gov/mining/pdfs/ccroadmap.pdf)

9. Mineral Processing Technology Roadmap. (Available at: http://www.oit.doe.gov/mining/pdfs/mptroadmap.pdf)

10. Anex, R., ed., “Industrial Ecology of Biobased Products,” Special issue of Journal of Industrial Ecology, 7(3-4), Summer-Fall, 2004. (ISSN: 1088-1980) (Available at: http://mitpress.mit.edu/jie)

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