Showing 75 results for Author: Zhiming Gao
Dec, 2023
Conference Paper
An engine-aftertreatment computational model was developed to support in-loop performance simulations of tailpipe emissions and fuel consumption associated with a range of heavy-duty (HD) truck drive cycles. For purposes of this study, the engine-out exhaust dynamics were simulated with a combination of steady-state engine maps and dynamic correction factors that accounted…
Dec, 2023
Journal
Battery electric vehicles (BEVs) are a critical pathway towards achieving energy independence and meeting greenhouse and criteria pollutant gas reduction goals in the current and future transportation sector. Emerging connected and automated vehicle (CAV) technologies further open the door for developing innovative applications and systems to leverage vehicle efficiency an…
Dec, 2023
Journal
A comprehensive selective catalytic reduction (SCR) model is developed to detail the global kinetic reactions in the catalyst which is involved in two type of sites for high- and low-temperature NH3 adsorption/desorption, as well as a low temperature H2O storage. The model accounts for the formation of ammonium nitrate in fast SCR and the decomposition formation of ammoniu…
Dec, 2023
Conference Paper
Natural gas furnaces are widely used in US residential and commercial building markets. An important issue for natural gas furnaces is serious corrosion and fouling problems caused by acidic gas, such as SOx. An advanced adsorption technology based on acidic gas trap (AGT) absorbers offers the possibility to remove SOx acidic gas from natural gas furnaces with high efficie…
Nov, 2023
Journal
A comprehensive forward-looking powertrain model with an efficiency-based control strategy was developed to achieve real-time optimization of plug-in hybrid electric buses while considering the real vehicle drivability and the practical operation of all powertrain components under real driving conditions. The control strategy is based on a supervisory control algorithm tha…
Nov, 2023
Conference Paper
Heat-driven ejector heat pumps use a supersonic ejector as a thermo-compressor to replace the mechanical compressor. Supersonic ejectors have many advantages in high-temperature heat pump (HTHP) applications, including high operating temperature tolerance, no need for lubrication, low maintenance, and low cost. The coefficient of performance of ejector HTHPs could be impro…
Nov, 2023
Conference Paper
This paper aims to present a wide-ranging analysis of Class 3-8 commercial vehicle electrification by means of developing a framework tool which uses a quantitative method of electric vehicle energy consumption and appropriate charging considerations, as well as using the Fleet DNA statistical drive behavior data, in evaluating and accelerating feasible or market-ready MD/…
Nov, 2023
ORNL Report
A micro–combined heat and power (mCHP) prototype powered by innovative opposed piston engine technology was developed to simultaneously provide electricity and heat to residential or light commercial buildings. The mCHP prototype targeted at residential applications includes an opposed-piston four-stroke (OP4S) engine, generator, rectifier, inverter, battery energy storage…
Nov, 2023
Conference Paper
Carbon dioxide (CO2) has been widely used as working fluid for the vapor-compression refrigeration systems in large marine device. Due to the potential energy efficiency and the favorable environmental properties of CO2 as a working fluid, CO2 heat pump water heater (HPWH) systems are regarded a promising technology for centralized domestic hot water (DHW) heating in resid…
Nov, 2023
Journal
Membrane-based dehumidification is a promising solution for building applications because of its low cost and limited energy consumption. Developing an efficient and cost-effective open-source code simulation tool is important for optimizing and evaluating such devices in HVAC applications. This paper describes a physics-based model, which accounts for the fundamental heat…
Nov, 2023
ORNL Report
Natural gas furnaces are the most common space heating equipment in the U.S. residential and commercial building markets. However, current residential natural gas condensing furnaces generate substantial acidic condensate as well as significant emissions of sulfur oxides (SOx), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons (HC), and methane (CH4) contributing t…
Nov, 2023
Journal
Natural gas furnaces are the most common space heating equipment in the U.S. residential and commercial building markets. However, current residential natural gas condensing furnaces generate substantial acidic condensate as well as significant emissions of sulfur oxides (SOx), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons (HC), and methane (CH4) contributing t…