Michael R. Swain

Hydrogen leakage into simple geometric enclosures

Abstract The following is a simplification of the hydrogen risk assessment method (Advances in Hydrogen Energy, Kluwer Academic Publishers, Plenum Press, Dordrecht, New York. p. 163–173. Proceedings of an American Chemical Society Symposium On Hydrogen Production, Storage and Utilization, August 22–26, New Orleans, Louisiana, 1999; Chemical Health and Safety 6 (3) (1999) 28.) previously developed at the University of Miami. It has been determined that in simple geometric enclosures, hydrogen leaks can be simulated using helium to predict the concentrations of the gas found near the ceiling after the initial transients disappear.

Passive ventilation systems for the safe use of hydrogen

These are the findings from a computer model study of hydrogen gas leakage in buildings. The gas cloud shape and size was predicted using FLUENT 3.03. This study investigated the influence of building geometry and passive ventilation on the formation of combustible gas clouds. That is to say; at what leakage rates, and for what length of time, leaking hydrogen can be ventilated from a properly designed building without producing a sizable quantity of combustible fuel-air mixture.

A comparison of H2, CH4 and C3H8 fuel leakage in residential settings

Abstract One of the boundary conditions for modeling gas cloud motion from a residential gas leak is the leakage rate at the source of the cloud. The literature presents estimates of the leakage rate of hydrogen relative to methane or propane based on diffusion, laminar flow and turbulent flow. These three methods yield significantly different values for the relative leakage rate of hydrogen. An experimental study was therefore conducted to measure the relative leakage rate of hydrogen compared with methane or propane for various leaks. The results from the experimental study were used as input to a computer model to predict combustible gas cloud size and motion in residential kitchens.

Hydrogen peroxide emissions from a hydrogen fueled engine

Abstract The previously used KMnO4 titration method for measuring hydrogen peroxide (H2O2) emissions in hydrogen fueled engines was found to produce erroneous results. A phenol-ferrous sulfate solution method was found to solve the problems associated with the use of KMnO4. H2O2 concentration in the exhaust of a hydrogen engine was found to be negligibly small during normal operation.

Considerations in the design of an inexpensive hydrogen-fueled engine

Present research efforts are pursuing the development of complex fuel delivery systems in an effort to successfully incorporate existing combustion chambers and coolant systems designed for hydrocarbon fuels into a hydrogen-fueled engine design. This paper presents the hypothesis that fundamental redesign of the combustion chamber shape and coolant passages can solve the hydrogen engine design problems more economically than redesign of the fuel delivery system.

The Application of a Hydrogen Risk Assessment Method to Vented Spaces

A comparison of the predicted results from a calibrated computational fluid dynamics (CFD) model with experimentally measured hydrogen data was made to verify the calibrated CFD model. The experimental data showed the method predicted the spatial and temporal hydrogen distribution in the garage very well. A comparison was then made of the risks incurred from a leaking hydrogen-fueled vehicle and a leaking liquefied petroleum gas (LPG)-fueled vehicle. The following is a brief description of the use of the Hydrogen Risk Assessment Method (HRAM) to analyze the risk associated with hydrogen leakage in a residential garage. The four-step method is as follows: 1. Simulation of an accident scenario with leaking helium 2. Calibration of a CFD model, of the accident scenario, using helium data 3. Prediction of the spatial and temporal distribution of leaking hydrogen using the calibrated CFD model 4. Determination of the risk incurred by hydrogen compared to a currently used fuel.

The effect of alternative gasolines on knock and intake valve sticking

Five fuels have been tested for 200 hours each in five separate but physically identical engines. The five fuels are, two shale oil-derived gasolines, two coal-derived gasolines, and one baseline unleaded gasoline. The results reported in this paper describe the tendency of the fuels to undergo postignition-induced-knock, and the indicators used for predicting the severity of this knock. The tendency of the fuels to produce intake valve sticking is also described. Additionally the chemical and physical properties of the alternative gasolines are reported herein. These results give further insight into the potential advantages and disadvantages of alternative gasolines. This paper addresses two questions relative to the effect that nonpetroleum-based gasolines have on two specific areas of engine performance; 1. How do the changes in chemical composition of the nonpetroleum-based gasolines affect knock. 2. How do the changes in chemical composition of the nonpetroleum-based gasolines affect intake valve sticking.

Abnormal combustion in a methanol fueled engine

Abnormal combustion in methanol fueled engines was investigated using a combination of ion gap detection and pressure versus crankangle measurements. The ability to differentiate between cool flames and surface ignition is shown. It is shown that cool flames do exist in methanol fueled engines

A non-intrusive surface ignition detector

A novel method and apparatus are described for the detection of surface ignition in internal combustion engines. The method is termed non-intrusive surface ignition detector (NSID). The NSID, its evolution, description and sample outputs are presented. The NSID method for analysing surface ignition can be employed without disturbing deposits in the combustion chamber or removing the cylinder head.

Modifications to Improve Fuel Consumption in the Remanufacture of Spark Ignition Engines for Electric Generators

This paper describes the development of a water cooled, lean burn, gaseous fueled engine designed for distributed power installations. Electric generators have become popular because they provide a portable supply of electrical power at consumer demand. They are used in critical need areas such as hospitals and airports, and have found their way into homes frequented with power outages or homes in remote locations. Gensets are available in a wide variety of sizes ranging from 1 kilowatt (kW) to thousands of kilowatts. In the mid-range the power sources are typically spark ignition, automotive type internal combustion engines. Since engines designed for automotive use are subject to different emission regulations, and are optimized for operation at RPMs and BMEPs above that of electric generator engines, modifications can be made to optimize them for gensets. This work describes modifications which can be made during remanufacturing an automotive engine to optimize it for use as a generator engine. While the work recognizes the potential for cost savings from the use of remanufactured automotive engines over that of using new automotive engines and the majority of the design constraints were adopted to reduce engine cost, the main focus of the work is quantifying the increase in fuel efficiency that can be achieved while meeting the required EPA emission requirements.This paper describes the seven combustion chamber designs that were developed and tested during this work. Friction reduction was obtained in both valve train and journal bearing design. The engine optimized for fuel efficiency produced a maximum brake thermal efficiency of 37.5% with λ= 1.63. This yielded an EPA test cycle average brake specific fuel consumption (BSFC) of 325 g/kW-hr. Modification of the spark advance and low load equivalence ratio to meet EPA Phase III emission standards resulted in an EPA test cycle average BSFC of 330 gm/kW-hr. When the engine used in this research was tested in its unmodified, automotive configuration under the EPA Compliant Test Cycle it’s EPA test cycle average brake specific fuel consumption was 443.4 gm/kW-hr. This is a 34% increase in fuel consumption compared to the modified engine.Copyright