Systems and methods for controlling on-board generation and use of hydrogen fuel mixtures
This is a system for generating hydrogen on-board the vehicle from compressed natural gas (CNG) in select ratios to create hydrogen-enriched CNG (HCNG) fuel for use in internal combustion engines. The on-board generation of hydrogen is comprised of a reforming system of CNG fuel with direct contact with exhaust gases. The reforming system controls for production of HCNG fuel mixtures is based on specific engine operating conditions. The vehicle's engine controls and operating parameters are modified for combustion of selective ratios of HCNG fuel mixtures throughout engine operating cycle. The reforming system controls and engine controls modifications are also used to minimize combustion emissions and optimize engine performance.
1. An engine system, comprising:
an on-board vehicle system configured to operate on-board a vehicle, the on-board vehicle system including:
a combustion system configured to combust natural gas to generate energy and exhaust gas;
a pre-reforming system configured to receive unreformed natural gas and coupled to the combustion system to receive at least a portion of the exhaust gas, the pre-reforming system configured to generate a partial oxidation reaction between the unreformed natural gas and the exhaust gas to generate partial oxidation reaction products;
a reforming system including a steam reformer, a carbon dioxide reformer, and a first water-gas-shift reformer, the reforming system coupled to the pre-reforming system and configured to reform the partial oxidation reaction products to produce reformed natural gas;
a mixing system coupled to the reforming system and configured to mix reformed natural gas and unreformed natural gas that is provided as the natural gas to the combustion system; and
a reforming control system coupled to the pre-reforming system and configured to control the supply of the exhaust gas to the pre-forming system so the supplied exhaust gas has a first ratio with the unreformed natural gas based on a first operating condition and is configured to control the supply of the exhaust gas so the supplied exhaust gas has a second ratio with the unreformed natural gas based on a second operating condition.
2. The engine system of claim 1 , wherein the reforming control system is further configured to control an amount of the unreformed natural gas delivered to the pre-reforming system as a ratio with the generated exhaust gas.
3. The engine system of claim 1 further comprising an engine control unit, and wherein the reforming system is integrated with the engine control unit.
4. The engine system of claim 3 , wherein the reforming control system is configured to extract the exhaust gasses from the combustion system based on inputs from the engine control unit for required amounts of steam and carbon dioxide for generation of hydrogen.