ASME PTC 53-2018 pdf – Mechanical and Thermal Energy Storage Systems.
Each Code will specify using either the higher or lower heating value, typically expressed as British thermal units per pound mass (kilojoules per kilogram).
Water vapor is one of the products of combustion for all fuels that contain hydrogen. The higher heating value of a fuel depends on whether this water vapor is allowed to remain in the vapor state or is condensed to liquid. En a bomb calorimeter, the products of combustion are cooled to the initial temperature and all of the water vapor formed during combustion is condensed to liquid. This gives the higher, or gross, heating value of the fuel with the heat of vaporization included in the reported value.1
incidental material: the amount of mass crossing the test boundary into the storage container during the standby state, which may increase the internal energy of the storage medium.
internal energy: a state variable; its change from one state to another is independent of the process that produces the change. Internal energy changes, rather than absolute values, are important. Internal energy may be set to any convenient base. For steam, this base has been set at the triple point, 32°F and 0.0891 psia (273.15 K and 611.2 Pa). The symbol for internal energy is u, and it is expressed as British thermal units per pound mass (joules per kilogram).1
material loss: the amount of mass leaving the test boundary from the storage container, which decreases the internal energy of the storage medium.
overall efficiency: the discharge energy divided by the sum of charge energy, fuel energy, secondary energy, and standby energy during a storage cycle, expressed as a percentage.
primary energy: the principal form in which energy is delivered to and from the ESS.
primary energy rate: the charge energy divided by the discharge energy during a storage cycle, expressed as kilowatt- hours per kilowatt-hour.
primary material: the principal form in which mass is delivered to and from the ESS. ramp rate: the rate of change of charge power or discharge power of an ESS.
rated discharge energy: the discharge energy delivered from the ESS designated in a test plan (such as maximum, minimum, nominal, or guaranteed), which may be derived from contracts, specifications, nameplates, guarantees, or other sources.
secondary energy: the amount of nonfuel energy and/or nonprimary energy entering the ESS during a storage cycle. secondary energy rate: the secondary energy divided by the discharge energy during a storage cycle, expressed as British thermal units per kilowatt-hour (kilojoules per kilowatt-hour).
standby energy: the amount of primary energy or fuel energy crossing the test boundary during the standby state. Standby energy may increase or maintain the internal energy of the storage medium or may be parasitic.
standby interval: a time duration during which the ESS is in the standby state.
standby power: the rate at which standby energy crosses the test boundary; the standby energy divided by the standby interval.
standby state: a condition in which neither the charging process nor the discharging process occurs. state of charge: the fraction of rated discharge energy present in the ESS.
storage container: a vessel, tank, reservoir, cavern, or other prescribed volume that holds primary material within the ESS.
storage cycle: a sequence comprising the charge process, a standby state, and the discharge process in which the state of charge is the same at the beginning and end of the sequence.
storage medium: the mechanical, chemical, or thermal material within the energy storage system whose internal energy is changed.
This Section provides guidance on performance testing of mechanical or thermal energy storage system(s) (ESS) and
outlines the steps required to plan, conduct, and evaluate a Code test of ESS performance. The subsections discuss the following:
(a) test plan (subsection 3-2)
(b) test preparations (subsection 3-3)
(c) conduct of test (subsection 3-4)
(d) calculation and reporting of results (subsection 3-5)
This Code includes procedures for testing the ESS to determine various types of test goals. It also provides specific instructions for multiple-party tests conducted to satisfy or verify guaranteed performance specified in commercial agreements.