Detailed thermodynamic investigation of an ICE-driven, natural gas-fueled, 1 kWe micro-CHP generator

• Published in: Energy conversion and management Vol. 166; no. C; pp. 663 - 673
• Main Authors: Taie, Zachary, West, Brian, Szybist, James, Edwards, Dean, Thomas, John, Huff, Shean, Vishwanathan, Gokul, Hagen, Christopher
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15.06.2018; Elsevier Science Ltd; Elsevier
• Subjects: algorithms; CHP; Cogeneration; Combustion; Data processing; Efficiency; Energy; Energy efficiency; Energy loss; ENGINEERING; Exergy; Exergy analysis; friction; Generators; heat recovery; Heat transfer; Internal combustion engine; Internal combustion engines; Measurement; Micro combined heat and power; Natural gas; Natural gas industry; Organic chemistry; primary energy; Residential cogeneration; State of the art; surveys; Thermal energy; Thermodynamic analysis; Thermodynamics; United States; Waste heat recovery; United States; Thermodynamic analysis; Internal combustion engine; CHP; Exergy analysis; Micro combined heat and power; Residential cogeneration
• ISSN: 0196-8904; 1879-2227; 1879-2227
• DOI: 10.1016/j.enconman.2018.04.077

•Round-robin testing of a 1 kWe mCHP generator at three independent laboratories.•First and Second law analyses were conducted on steady state measurements.•The system energy efficiency was 23.5 ± 0.4% with a utilization factor of 74.5 ± 3.2%.•The second law total efficiency was 30.2 ± 2.3%.•Sub-component ICE and electric generator analysis were conducted and reported. The purpose of this work is to record the baseline performance of a state-of-the-art micro-combined heat and power (mCHP) system. A second goal of this work is to provide detailed thermodynamic first and second law performance measurements of the internal combustion engine and generator subsystems. A global technology survey was conducted to identify the leading mCHP systems in the 1 kW electric range. The Honda ECOWILL was identified as the state-of-the-art system in the United States, and an unused unit was procured. The ECOWILL underwent round-robin performance testing at three independent laboratories. First law (energy) and second law (exergy) analyses were conducted on the steady state data. Analysis revealed the ECOWILL operated at a first law electrical efficiency of 23.5 ± 0.4% and a utilization factor of 74.5 ± 3.2%. The primary energy loss was heat transfer from the device, followed by chemical and thermal energy in the exhaust stack. The second law analysis showed the ECOWILL operated at a second law electrical efficiency of 23.1 ± 0.4% and total (including exergy in both the electrical and recovered waste heat streams) second law efficiency of 30.2 ± 2.3%. Key areas of exergy destruction were, in decreasing magnitude, heat transfer, combustion irreversibility, and generator and friction losses.