ASME EA-3:2009 pdf free download

ASME EA-3:2009 pdf free download.Energy Assessment for Steam Systems.
ASME EA-3 covers steam systems that are defined as a system containing steam generator(s) or other steam source(s), a steam distribution network and end-use equipment. Cogeneration and power generation components may also be elements of the system (gas turbines, backpressure steam turbines, condensing steam turbines). If steam condensate is collected and returned, the condensate return subsystem is a part of the steam system.
This Standard sets the requirements for preparing for, conducting, and reporting the results of a steam system energy assessment (hereafter referenced as an “assessment”) that considers the entire system, from energy inputs to the work performed as the result of these inputs. An assessment complying with this Standard need not address each individual system component or specific system within an industrial facility with equal weight; however, it shall he sufficiently comprehensive to identify the major opportunities for improving the overall energy performance of the steam system. This Standard is designed to be applied primarily at industrial facilities, but most of the specified procedures can be used in other facilities such as those in the institutional and commercial sectors.
The scope of work shall be to complete a comprehensive assessment on a steam system. In the case of an exceptionally large facility, it may be desirable to focus on only one of several steam systems. As a result, the assessment plan should be developed for this specific system only. If an energy stream derives from or is din’cted to an adjacent system (possibly in an adjacent energy-supplying or receiving facility), then the details of the energy streams (e.g., electricity, steam, natural gas) shall be considered as part of the assessment of the target system.
Assessments involve collecting and analyzing data on system design, operation, energy use, and performance, and identifying energy performance improvement opportunities for system optimization. An assessment may also include recommendations for improving resource utilization, reducing per unit production cost, reducing life cycle costs, and improving environmental performance related to the assessed system(s). Assessment activities shall include but are not limited to engaging facility personnel and providing information about the assessment process;
Mass and energy balances applied to a piece of equip. ment, a subsystem, or theentire system arestatementsof the principles of mass and energy conservation, which need to be understood in a steam system. Mass and energy balances shall be applied at any point in a steam system where flows of mass (e.g., water and steam) and energy (e.g., work and heat) enter and leave a system or component at flow distribution points. As examples, boiler efficiency, the use of steam in turbines, process equipment steam consumption, and steam consumption in boiler auxiliaries are all manipulations of mass and energy balances, A mass and/or energy balance should be needed for any or all of the following purposes:
(a) to calculate an unknown quantity (e.g., steam flow to a heat exchanger) from values of known or estimated quantities
(b) to verify that a set of measured and estimated values satisfies the operating conditions of the equipment
(c) to evaluate component efficiency and performance (d) to determine the impacts of system modifications In the case of unknown quantities in a mass or energy balance, it may be necessary to make reliable estimates of one or more needed values. Reliable estimates shall be based on the experience of the assessment team members reflected in typical values (e.g., turbine isentropic efficiency), plant experience in making similar measurements, design data (e.g., heat exchanger capacity) and available physical evidence (e.g., steam leak plume length).
The accuracy or closure of the applied mass and energy balances should be in concert with the goal of the evaluation. For example, if an order-of-magnitude estimate is desired to establish general operating characteristics, then the tolerance of the mass and energy balances can be relaxed. However, if the end result of the analysis in question is to decide a specific project execution strategy, then the critical factors shall be accurately identified.