Description

ASME PTC 50 – Fuel Cell Power Systems Performance

This Code provides test procedures, methods and definitions for the performance characterization of fuel cell power systems. Fuel cell power systems include all components required in the conversion of input fuel and oxidizer into output electrical and thermal energy. Performance characterization of fuel systems includes evaluating system energy inputs and electrical and thermal outputs to determine fuel-to-electrical energy conversion efficiency and where applicable the overall thermal effectiveness. These efficiencies will be determined to an absolute uncertainty of less than ± 2% at a 95% confidence level. (For example, for a calculated efficiency of 40%, the true value lies between 38% and 42%.)

This Code applies to all fuel cell power systems regardless of the electrical power output, thermal output, fuel cell type, fuel type, or system application.

Fuel cell power systems contain an assembly of electrochemical cells, which oxidize a fuel to generate direct current electricity. Balance-of- plant subsystems may include controls, thermal management, a fuel processor and a power conditioner. Some fuel cell power systems may contain additional power generating equipment such as steam generators, gas turbine generators, or micro-turbine generators. The net power output and all the fuel input to the system shall be taken into account in the performance test calculations.

This Code applies to the performance of overall fuel cell power systems. The Code addresses combined heat and power systems, that is, the generation of electricity and usable heat at specific thermal conditions. It does not address the performance of specific subsystems nor does it apply to energy storage systems, such as regenerative fuel cells or batteries. It also does not address emissions, reliability, safety issues, or endurance. This Code contains methods and procedures for conducting and reporting fuel cell system testing, including instrumentation to be used, testing techniques, and methods for calculating and reporting results. The Code defines the test boundary for fuel and oxidant input, secondary energy input and net electrical and thermal energy output. At these boundaries, this Code provides procedures for measuring temperature, pressure, input fuel flow and composition, electrical power, and thermal output. The Code provides procedures for determination of electrical efficiency or heat rate and overall thermal effectiveness at rated or any other steady state condition. The Code also provides the method to correct results from the test to reference conditions.