Thermoelectric Generation From Exhaust Heat in Electrified Natural Gas Trucks: Modeling and Analysis of an Integrated Engine System Performance Improvement

TY - JOUR

T1 - Thermoelectric Generation From Exhaust Heat in Electrified Natural Gas Trucks: Modeling and Analysis of an Integrated Engine System Performance Improvement

AU - Sok, Ratnak

AU - Kusaka, Jin

AU - Nakashima, Hisaharu

AU - Minagata, Hidetaka

AU - Dimitriou, Pavlos

AU - Liu, Jinlong

PY - 2023/2/14

Y1 - 2023/2/14

N2 - Using thermoelectric generators (TEG) to reduce exhaust heat loss from internal combustion engines can improve emissions and the fuel economy of conventional and electrified vehicles. However, TEG potentials have not been investigated in hybridized, compressed natural gas (CNG), twin-turbocharged, and spark-ignited (SI) engines. This work demonstrates TEG's effectiveness in boosting a hybridized 3.0 L CNG engine using model-based development. TEG experiments are performed to measure thermal performances under different inlet gas conditions for model validations. Simplified user-defined functions of flow friction and heat transfer coefficients are used to calibrate the model. A fast-calibration model can reproduce measured heat transfer, pressure drop, and thermal performances. The engine performances are validated against measured 35 steady-state conditions from the production engine used in light-duty CNG trucks under the JE05 drive cycle. Next, the model is connected to the turbocharging system downstream of the well-calibrated four-cylinder SI engine model. Under the peak performance condition (peak brake thermal efficiency BTE at 2400 RPM and 102 kW load), the results show that the engine BTE is improved by 0.56% using a 7 × 9 TEG module arrangement (three-sheet TEG with 1.5× A4 size). A 9 × 10 arrangement can enhance the BTE to 0.8%. Effective electrical power is generated up to 1.168 kW from the TEG, depending on the JE05 operating regions, without significant brake power loss.

AB - Using thermoelectric generators (TEG) to reduce exhaust heat loss from internal combustion engines can improve emissions and the fuel economy of conventional and electrified vehicles. However, TEG potentials have not been investigated in hybridized, compressed natural gas (CNG), twin-turbocharged, and spark-ignited (SI) engines. This work demonstrates TEG's effectiveness in boosting a hybridized 3.0 L CNG engine using model-based development. TEG experiments are performed to measure thermal performances under different inlet gas conditions for model validations. Simplified user-defined functions of flow friction and heat transfer coefficients are used to calibrate the model. A fast-calibration model can reproduce measured heat transfer, pressure drop, and thermal performances. The engine performances are validated against measured 35 steady-state conditions from the production engine used in light-duty CNG trucks under the JE05 drive cycle. Next, the model is connected to the turbocharging system downstream of the well-calibrated four-cylinder SI engine model. Under the peak performance condition (peak brake thermal efficiency BTE at 2400 RPM and 102 kW load), the results show that the engine BTE is improved by 0.56% using a 7 × 9 TEG module arrangement (three-sheet TEG with 1.5× A4 size). A 9 × 10 arrangement can enhance the BTE to 0.8%. Effective electrical power is generated up to 1.168 kW from the TEG, depending on the JE05 operating regions, without significant brake power loss.

KW - thermoelectric generator

KW - heat exchanger

KW - heat recovery

KW - CNG hybrid engine

KW - system efficiency

KW - energy conversion/systems

KW - energy systems analysis

KW - fuel combustion

U2 - 10.1115/1.4056722

DO - 10.1115/1.4056722

M3 - 文章

SN - 0195-0738

VL - 145

JO - Journal of Energy Resources Technology, Transactions of the ASME

JF - Journal of Energy Resources Technology, Transactions of the ASME

IS - 7

ER -