The project will involve the use of two test beds—one in a hydrogen production plant (Praxair), and the other in a forging/machining/heat treating manufacturing line operation (General Dynamics). For each test bed, sensor-driven modeling, measurement, and simulation systems, in conjunction with the Smart Manufacturing Platform, will be developed, deployed, and operated, allowing energy consumption to be managed in real time. An Energy Dashboard developed for each test bed will provide situation awareness by integrating the energy productivity metrics with real-time information. Previously unavailable intelligence will be used to identify overall operations improvement opportunities at both test beds.
Praxair Steam Methane Reforming (SMR)
In SMR, methane (natural gas) and steam are converted into hydrogen, carbon monoxide, and carbon dioxide. The reforming reactions occur in catalyst filled tubes in a furnace. SMR is used extensively to produce hydrogen, synthesis gas, ammonia, and methanol at over 900 large facilities worldwide. The proposed test bed uses a SMR hydrogen production plant operated by Praxair, the largest industrial gas supplier in the U.S. Using sensor driven modeling, new measurement techniques, and simulation systems in conjunction with the Smart Manufacturing Platform, Project Smart Manufacturing intends to increase energy productivity in the SMR process and demonstrate a substantial reduction in waste heat generation. The test bed will research new sensor technologies and novel computer simulation and optimization tools in both process design and operations to pursue significant improvements in energy and operating productivity in SMR plants, regardless of end product.
Energy saving is possible as a result of enabling the test bed with modeling capability and sensors to better control variations in temperature and composition across the furnace in real-time, achieving maximum energy productivity and reliability while minimizing natural gas and steam maldistribution across the tubes. Reformers can be modeled with a three dimensional (3D) computational fluid dynamics (CFD) model, but it is difficult to solve these models in an amount of time that would make it amenable to practical online process changes. It is also difficult to define improvements in these process controls with currently available sensor technology. For example, thermocouples placed inside the furnace are challenged to survive in the high temperature environment, and the installation of automatic valves for the adjustment of flow rates to individual tubes is cost prohibitive. The test bed planned in Project Smart Manufacturing will address these limitations. Lower order models that adequately describe the reformer to define energy use improvements will be identified. Sensing technology will be deployed to measure heat flux and estimate tube wall temperature at multiple locations within an SMR furnace. Going forward, these low order modeling capabilities can be extended to multiple facilities across the U.S.
General Dynamics Forging/Machining/Heat Treating
Forging processes frequently utilize furnaces that operate in excess of 1,400 degrees Fahrenheit. Many forging operations are performed under operator control with inadequate measurements of key operating parameters, such as furnace temperature profiles, and fundamental models for analyzing operation data are usually not available to plant engineers. General Dynamics, and many other companies in the forging industry, also lack the internal engineering resources to develop new process control and energy management systems, and using external resources to develop new systems can be very expensive. Unfortunately, without adequate sensors, controls, modeling, and metrics, significant reductions in waste heat are not possible. Using data driven modeling, new measurement techniques, and simulation systems in conjunction with the Smart Manufacturing Platform, Project Smart Manufacturing intends to determine the causes of non-uniformity in the temperature profiles in the furnaces used to process artillery shells, identify opportunities to reduce energy use in each process step, and across the process steps, and demonstrate a 30% reduction in waste heat generation.
Many of tools described in the Praxair test bed can also be applied to General Dynamic’s heat treating process for artillery shells. General Dynamics currently operates four forging furnaces at its Scranton, PA facility, one of which has recently been modified to operate under automatic control. This change resulted in energy savings of 30%. Under Project Smart Manufacturing, automatic controls will be installed in another furnace and upgraded in order to be able to use advanced modeling and control, and provide the baseline capability for addressing energy usage and waste heat losses along the entire manufacturing line. The main focus of Project Smart Manufacturing would be to reduce the major waste heat losses in the flue gas and water cooling streams, which make up around 40% of the gross fuel heat input.