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Transport Refrigeration Unit, or TRU, is an example of a diesel emission source that will be regulated in the future. The TRU is used to provide refrigerated space during the transport of fruits, vegetables, meat, pharmaceuticals, beverages, and any other product that needs a temperature controlled environment while being transported. TRUs are used in all modes of transport, on rail cars, on ocean going shipping containers, over the road truck trailers and even on airplane Unit Load Devices. Policy making bodies, understanding the adverse effects of diesel emissions, noise pollution, and fuel consumption have started to pass legislation in an effort to curtail transport diesel emissions. At the local level many states as well as some municipalities have instituted policy designed to eliminate these sources of pollution.

In this paper a model of Trailer Refrigeration Units, TRUs, has been developed to quantify the fuel economy and emissions benefits of alternative power systems. Trailer refrigeration units (TRUs) are refrigeration systems typically powered by a separate diesel engine, and they are used to deliver fresh and frozen food products. The products can be very sensitive to temperature variation and maintaining the proper environment is very important. The diesel engines currently used to power the refrigeration system can contribute to high amount of local emissions at the loading warehouse. A promising future alternative is the use of fuel cell auxiliary power units (APUs). In this paper we have developed a MATLAB/Simulink based modeling of TRUs, and we have used the model to quantify the benefits of alternative power systems. The simulation model consists of an unsteady thermal modeling of TRUs that is coupled to the APU.

In recent years emission control agencies have turned their attention to to the cleanup of diesel engines, both mobile and stationary. This paper is one of the first attempts to characterize the load and emissions of a subsection of stationary diesel emissions, specifically Truck/Trailer Refrigeration Units (TRUs). These devices are used to keep refrigerated or frozen cargo cold when it is being shipped/delivered. Two general sizes of TRUs were tested, smaller TRUs for cooling box trucks, used for local deliveries, and large TRUs, used for long hauling and very large deliveries. After observing a matrix of these units over a large spectrum of temperatures it was found that, although there were multiple control strategies, they all heavily relied on pulling the trailer down to the set point temperature as fast as the engine and refrigeration unit would allow.

This paper presents model-based predictions of the performance of diesel, compressed natural gas (CNG), and hybrid buses on bus routes in the City of San Francisco. The bus route details were obtained by recording time-series measurements of speed and grade during actual runs of buses on the city streets under different traffic conditions. The transit buses' physical and mechanical characteristics were obtained from manufacturers' data and chassis dynamometer testing of the buses on different city cycles. Both the bus routes and the bus performance characteristics were put into the simulation package ADVISOR from the National Renewal Energy Laboratory (NREL). The most extreme results were for the San Francisco routes that have high grades. The high grades cause performance and emissions problems for both the diesel and CNG buses relative to the hybrid bus.

As part of a California Selective Catalyst Reduction (SCR) system demonstration and evaluation project [13], the authors and their industrial partners have conducted engine dynamometer emissions tests of SCR systems. The transient Federal Test Procedure (FTP) cycle and 13 Mode European Stationary Cycle (ESC) were conducted using certification diesel fuel with 300-500 ppm of sulfur. This paper reviews the performance of the first system to meet the goal of attaining 1 g/bhp-hr NOx emissions in the transient FTP cycle on a 1999 DDC Series 60 engine that has an initial 4 g/bhp-hr level. This paper discusses key characteristics of a typical automotive SCR system and then presents the results and analysis of the engine dynamometer emission testing of a SCR system. The paper concludes with a discussion of the challenges involved in on-road operation of the system.

Class 8 trucks idling consume significant amounts of diesel fuel each year in North America and abroad. Engine idling occurs to power sleeper compartment accessories (air conditioners, refrigerators, televisions), and to avoid start-up problems. The alternative power sources available to reduce the need for idling (i.e. battery packs, auxiliary generators, direct-fired heaters, absorption coolers) all have severe economic and technical drawbacks that have limited their market acceptance. Freightliner Corporation, in conjunction with its development partner XCELLSiS Corp. has constructed a fully functioning concept demonstration vehicle that utilizes Proton Exchange Membrane (PEM) fuel cell technology in an auxiliary power unit (FC APU). While fuel cell powertrains continue to face significant technical and economic barriers, with additional development truck auxiliary power applications may offer a viable near-term market for small (1 - 5 kW) fuel cells.

The Institute of Transportation Studies at the University of California, Davis (ITS-Davis) has brought together a group of public and industrial partners to demonstrate and evaluate the Siemens-Westinghouse Urea-Selective Catalyst Reduction System (SINOx™). The SINOx System has the potential to generate major reductions in nitrogen oxides (NOx) and the volatile organic fraction (VOF) of particulate (PM) from heavy-duty diesel engines, without increasing fuel consumption and carbon dioxide (CO2) emissions. This demonstration began with engine bench testing at Detroit Diesel Corporation to calibrate the system to attain 1 g/bhp-hr NOx emissions in the transient portion of the US-FTP on a 1999 Series 60 engine that has a 4 g/bhp-hr emission level. The second phase of the project entails an on-highway demonstration of a set of ten, Freightliner Class 8 heavy-duty diesel vehicles. These vehicles are part of the Valley Material Transport fleet based in French Camp, California.

For studying the effects of injection system properties and combustion chamber conditions on the penetration lengths of both the liquid and the vapor phase of fuel injectors in Diesel engines, a holistic injection model was developed, combining hydraulic and spray modeling into one integrated simulation tool. The hydraulic system is modeled by using ISIS (Interactive Simulation of Interdisciplinary Systems), a one dimensional in–house code simulating the fuel flow through hydraulic systems. The computed outflow conditions at the nozzle exit, e.g. the dynamic flow rate and the corresponding fuel pressure, are used to link the hydraulic model to a quasi–dimensional spray model. The quasi–dimensional spray model uses semi–empirical 1D correlation functions to calculate spray angle, droplet history and droplet motion as well as penetration lengths of the liquid and the vapor phases. For incorporating droplet vaporization, a single droplet approach has been used.

A research effort sponsored by Yamaha Motors, LTD. was undertaken to investigate exhaust system and exhaust silencing concepts for two-stroke engines. A complete one-dimensional gas dynamic computer program was developed for power-tuned exhaust systems. This program provides great insight into the actual nonlinear wave behavior of both conventional and innovative power-tuned exhaust systems. In addition, the simulated outlet flow rate has been coupled with the spherical wave equation in order to predict sound levels at any distance from the engine. An overall engine model has been developed for simulation of the internal gas dynamic behavior throughout the engine. This model includes the combustion and induction aspects of the engine cycle as well as a simplified exhaust system model. Engine power and torque can be predicted. The main use of the engine model is in comparative studies of engine parameter variations.