shown are gas turbine inlet temperature and hybridsolar energy percent. ... . arrangement.of solar and fossil fuel input to the gas-turbine cycle exhaust ...... Burner. - --Fossil fuel. HX. [,---. Solar. Exhaust. I gas path. Figure 14, Concept for ...

A method of ammonia production for a selective catalytic reduction system is provided. The method includes producing an exhaust gas stream within a cylinder group, wherein the first exhaust gas stream includes NOx. The exhaust gas stream may be supplied to an exhaust passage and cooled to a predetermined temperature range, and at least a portion of the NOx within the exhaust gas stream my be converted into ammonia.

Repowering of existing coal-fired power plants is often accomplished by adding gas turbines. In this paper we assume that the gas turbine exhaust is used for feed water preheating.Typical gas turbine exhaust temperatures are in the range 450-600C whereas typical boiler inlet temperatures are 250-300C. The big difference in temperature between exhaust and water prevents an efficient exchange of heat. One way to lower the exhaust temperature is to expand the gas to sub atmospheric pressure. The result is a 50% increase in possible installed gas turbine power.

A combined cycle electric power plant includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The steam generator includes a superheater tube through which a fluid, e.g. water, is directed to be additionally heated into superheated steam by the exhaust gas turbine gases. An afterburner further heats the exhaust gas turbine gases passed to the superheater tube. The temperature of the gas turbine exhaust gases is sensed for varying the fuel flow to the afterburner by a fuel valve, whereby the temperatures of the gas turbine exhaust gases and therefore of the superheated steam, are controlled. The afterburner fuel flow is controlled through a feedforward setpoint signal derived as a predetermined function of sensed gas turbine exhaust temperature.

An exhaust gas purification system for a lean burn engine includes a thermal mass unit and a NO.sub.x conversion catalyst unit downstream of the thermal mass unit. The NO.sub.x conversion catalyst unit includes at least one catalyst section. Each catalyst section includes a catalytic layer for converting NO.sub.x coupled to a heat exchanger. The heat exchanger portion of the catalyst section acts to maintain the catalytic layer substantially at a desired temperature and cools the exhaust gas flowing from the catalytic layer into the next catalytic section in the series. In a further aspect of the invention, the exhaust gas purification system includes a dual length exhaust pipe upstream of the NO.sub.x conversion catalyst unit. The dual length exhaust pipe includes a second heat exchanger which functions to maintain the temperature of the exhaust gas flowing into the thermal mass downstream near a desired average temperature.

Simulations of exhaust nozzle flows are typically conducted assuming the gas is calorically perfect, and typically modeled as air. However the gas inside a real nozzle is generally composed of combustion products whose thermodynamic properties may differ. In this study, the effect of gas model assumption on exhaust nozzle simulations is examined. The three methods considered model the nozzle exhaust gas as calorically perfect air, a calorically perfect exhaust gas mixture, and a frozen exhaust gas mixture. In the latter case the individual non-reacting species are tracked and modeled as a gas which is only thermally perfect. Performance parameters such as mass flow rate, gross thrust, and thrust coefficient are compared as are mean flow and turbulence profiles in the jet plume region. Nozzles which operate at low temperatures or have low subsonic exit Mach numbers experience relatively minor temperature variations inside the nozzle, and may be modeled as a calorically perfect gas. In those which operate at the opposite extreme conditions, variations in the thermodynamic properties can lead to different expansion behavior within the nozzle. Modeling these cases as a perfect exhaust gas flow rather than air captures much of the flow features of the frozen chemistry simulations. Use of the exhaust gas reduces the nozzle mass flow rate, but has little effect on the gross thrust. When reporting nozzle thrust coefficient results, however, it is important to use the appropriate gas model assumptions to compute the ideal exit velocity. Otherwise the values obtained may be an overly optimistic estimate of nozzle performance.

Enhancing CO"2 concentration in exhaust gas has been considered as a potentially effective method to reduce the penalty of electrical efficiency caused by CO"2 chemical absorption in post-combustion carbon capture systems. Supplementary firing is an option that inherently has an increased CO"2 concentration in the exhaust gas, albeit a relatively low electrical efficiency due to its increased mass flow of exhaust gas to treat and large temperature difference in heat recovery steam generator. This paper focuses on the methods that can improve the electrical efficiency of the supplementary fired combined cycles (SFCs) integrated with MEA-based CO"2 capture. Three modifications have been evaluated: (I) integration of exhaust gas reheating, (II) integration of exhaust gas recirculation, and (I...

...certain low-pressure turbine (LPT) rotor stage 3 disks installed. That AD currently...of the high-pressure turbine (HPT) rotor stage 1...the LPT rotor stage 3 disk under certain conditions...requires repetitive exhaust gas temperature (EGT)...

The phosphoric acid mixed into the exhaust air of the fuel cell reacts chemically with the structural materials such as stainless steel of pipes in which fuel cell exhaust air flows and the air preheater, and produces phosphoric acid compound. This compound accumulates on the surface, grows with the passage of time to block up the exhaust air passage, and causes production of pin holes at welded area by corrosion. This invention is concerned with a phosphoric acid fuel cell, wherein an inlet for exhaust oxidizer gas to flow into the heat exchanger is provided at the lower part of the heat exchanger, and an outlet is provided at the upper part of the heat exchanger for flowing exhaust oxidizer gas from the heat exchanger. As a result, even when vapor in the exhaust oxide gas is condensed to become water, the water drops to contact with high temperature exhaust oxidizer gas at the lower area and evaporates to avoid production of strong acidic drain caused by phosphoric acid because high temperature exhaust oxidizer gas containing phosphoric acid forms upward flow ascending from the lower part to the upper part of the air preheater. 5 figs.

Melting techniques of ash generated in municipal solid waste incinerators can be divided into a fuel process and an electric process. The fuel process was developed for applying to waste treatment such as sludge. The fuel process discharges a large amount of exhaust gas. Then, downsizing of exhaust gas treatment equipment can not be expected. However, the residence time in the high temperature region can be maintained due to a large quantity of heat from the exhaust gas, which results in the enhanced decomposition of dioxins. On the other hand, for the electric process, treatment of exhaust gas is easy due to a smaller amount of exhaust gas. Then, the initial cost of exhaust gas treatment equipment can be suppressed. However, for both the processes, it is not avoidable to regenerate the dioxins during cooling process of exhaust gas. Thorough control of temperature and protection of adhesion and deposition of dusts are essential for reducing the dioxins. All of items from the elution tests of slags satisfy the landfill standard. For recycling and reusing the molten slag, it is necessary to establish the social and technical rule as well as to arrange the treatment manual and standard and to construct the MSDS (material safety data sheet). 10 refs., 5 figs., 2 tabs.

We have found that the exhaust gas from many incineration plants of municipal solid wastes (MSW) show significant mutagenic activities. The mutagenic activities of exhaust gas from incineration plants of the other wastes have not been studied in detail. Here, we analyzed the mutagenic activities and compounds in exhaust gas and ash from seven sludge incineration plants. Some samples of the exhaust gas from the sludge incineration plants showed high mutagenic activities; although, none of the ash residues showed mutagenic activities. There was no relationship between the mutagenic activities and furnace types, the plant size or the apparent residence time of the gas in the furnace. The mutagenic activities of the exhaust gas were produced during incomplete combustion at lower temperatures. Direct mutagenic activities without S9 mix were higher than indirect mutagenic activities with S9 mix which was made from rat liver homogenate and was used to test mutagenic activity after metabolism. These results are different to those of MSW incineration plants. We analyzed the mutagenic compounds in the exhaust gas by GC/MS after fractionation by HPLC, but they could not be identified. We found that the mutagenic compounds in the exhaust gas were different from the compounds that were produced from the MSW incineration plants. We believed that these mutagenic compounds might be non-volatile and more polar than the heterocyclic amines, Trp-P-2, Trp-P-1 and Glu-P-1, which are typical mutagenic compounds in sewage and sludge

The conceptual design and analysis of a film cooled exhaust duct for a gas core rocket test cavity is described. The cavity exhaust has a temperature of 4000 K and 200 atmosphere of pressure. The film cooled duct design uses seeded hydrogen coolant flow to reduce the duct outlet temperature to 850 K, and the maximum duct wall temperature to below 700 K. With this design less than 1 percent of the uranium fuel flow rate in the exhaust plates out on the duct walls.

De-NOx catalytic systems generally perform better in rich or stoichiometric engine operating conditions due to high hydrocarbon (HC) concentrations in the exhaust gas. However, the hydrocarbon concentration in a diesel engine is typically low, so post or supplemental fuel injections into the exhaust gas have been employed in order to increase the HC concentration. A hydrocarbon-type lean NOx trap (HC-LNT) catalyst system that is a De-NOx system based on NOx-absorbing catalyst has also been developed to optimize control of the external HC injection into the diesel exhaust pipe. The system has a secondary injector that injects diesel fuel (HC) into an exhaust manifold. The typically high temperature (250-350degreeC) in the exhaust manifold affects the spray behavior of the secondary injector...

...spot-welded V-band exhaust couplings that...certain Piper Aircraft, Inc. Models...The V-band exhaust coupling attaches...to hot exhaust gases. Several failures...to Commander Aircraft Company Model...design V-band exhaust coupling has...high temperature gases inside the...

A method and apparatus for controlling a temperature in a combustion cylinder in an internal combustion engine. The cylinder is fluidly connected to an intake manifold and an exhaust manifold. The method and apparatus includes increasing a back pressure associated with the exhaust manifold to a level sufficient to maintain a desired quantity of residual exhaust gas in the cylinder, and varying operation of an intake valve located between the intake manifold and the cylinder to an open duration sufficient to maintain a desired quantity of fresh air from the intake manifold to the cylinder, wherein controlling the quantities of residual exhaust gas and fresh air are performed to maintain the temperature in the cylinder at a desired level.

product, or process disclosed, or represents that its use would not infringe privately .... An increase in exhaust gas temperature is characteristic of the adiabatic engine. .... A Shimadzu Model 6AM gas chromatograph with an integral ther- .... indicate two (2) peaks with molecular weights of 330 and 348. ...... on an ideal basis.

Disclosed is a pulverizing, drying and transporting system for a puvlerized fuel of a blast furnace of the type having at least one hot stove for supplying hot blast air, said hot stove also providing hot stove exhaust gas. The system includes a pulverizing and drying unit for pulverizing lump raw fuel and drying the pulverized fuel. The hot stove gas is supplied to the pulverizing and drying unit. The hot stove exhaust gas dries the pulverized fuel and conveys it to a pulverized fuel collecting and separating device which separates the gas from the pulverized fuel. The line supplying the hot stove gas to the pulverizing and drying unit includes a heating device for selectively supplying additional heat to the hot stove exhaust gas. Moreover, the line for supplying the hot stove gas to the pulverizing and drying unit can include at least one of a temperature stabilizing device and a cooling device. The heating and cooling devices are controlled by a controller sensitive to the gas temperature at the outlet of the pulverizing and drying unit for maintaining the gas temperature at the outlet of the pulverizing and drying unit at a constant level. The temperature stabilizing device maintains the gas temperature at the outlet of the temperature stabilizing device at a designated level.

Due to increasingly stringent emission legislation, it is essential to find a solution of eliminating nitrogen oxides (NOx) from diesel exhaust gas. Non-thermal plasma (NTP) approach has been studied for years and has shown advantages. In this study, NOx removal from simulated diesel exhaust gas by a dielectric barrier discharge needle-to-cylinder reactor under room temperature condition is presented. The dielectric barrier consists of a diesel particulate filter (DPF) putting in the discharge field. A simulation gas of N2, NO and O2 combined with particulate matters (PM) was used as the test gas. PM was loaded from a diffusion flame PM generator. The effect of PM and oxygen fraction in exhaust gas on NOx removal characteristics was investigated experimentally. The results showed that PM p...

Nowadays, increasing crude oil prices and environmental pollution problems have lead to investigation of alternative fuel necessities, such as vegetable oils for internal combustion engines. This article presents the possibility of using cottonseed oil-kerosene blends in compression ignition engines. Engine performance and exhaust emissions were examined and diesel fuel was used as a basis for comparison. The influences of using various blended cottonseed oil-kerosenes on brake specific fuel consumption, exhaust gas temperature, and exhaust emissions values were investigated. Experimental results indicated that engine performance and brake specific fuel consumption were slightly different and SOx emissions were remarkably different from diesel fuel usage.

Engine emissions of CO, NMHC and ashes are easily lowered through a low-cost exhaust gas processing, while NOx processing in fumes is rather complex and environmentally hazardous; thus, engine manufacturers have emphasized their researches for NOx decrease on the engine design: lower combustion temperature in diesel engines through water cooling or air/air exchanger, lean mixture with excess air (open chamber or pre-chamber) in spark ignition gas engines. Examples of modifications in Caterpillar engines are given. Exhaust gas processing for CO, NMHC, NOx (3 way catalytic purifier, selective catalytic reduction) and ashes is also discussed

This report describes tests conducted at the Langley Memorial Aeronautical Laboratory on an "air-inducting" exhaust manifold for aircraft engines. The exhaust gases from each cylinder port are discharged into the throat of an exhaust pipe which has a frontal bellmouth. Cooling air is drawn into the pipe, where it surrounds and mixes with the exhaust gases. Temperatures of the manifold shell and of the exhaust gases were obtained in flight for both a conventional manifold and the air-inducting manifold. The air-inducting manifold was installed on an engine which was placed on a test stand. Different fuels were sprayed on and into the manifold to determine whether the use of this manifold reduced the fire hazard. The flight tests showed reductions in manifold temperatures of several hundred degrees, to values below the ignition point of aviation gasoline. On the test stand when the engine was run at idling speeds fuels sprayed into the manifold ignited. It is believed that at low engine speeds the fuel remained in the manifold long enough to become thoroughly heated, and was then ignited by the exhaust gas which had not mixed with cooling air. The use of the air-inducting exhaust manifold must reduce the fire hazard by virtue of its lower operating temperature, but it is not a completely satisfactory solution of the problem.

The simple small low-NOx burners, LGX type for medium pressure and LGXL type for low pressure, of Sunray Relnetsu Co. Ltd. were reported. 13A gas or LPG was used as fuel for both type burners, and NOx emission less than 60 ppm was achieved. Various NOx reduction measures were adopted such as membrane combustion, scatter flames and exhaust gas self-recirculation. The membrane combustion was formed by energy of fuel gas for LGX type one or energy of primary air for LGXL type one, and the scatter flames were formed by scatter supply of gas and air. Using the baffle plate with alternate injection and baffle sections for air, low peak combustion temperature and uniform temperature distribution were attained through self-recirculation of combustion gas from the baffle sections to a combustion center. In addition, further several measures were adopted such as baffle plate with an optimum scattering structure to reduce an oxygen content in exhaust gas. 8 figs.

The paper presents the preliminary results of the waste heat recovery investigations for an agricultural tractor engine (7.4 dm3) and excavator engine (7.2 dm3) in real operating conditions. The temperature of exhaust gases and exhaust mass flow rate has been measured by precise portable exhaust emissions analyzer SEMTECH DS (SENSORS Inc.). The analysis shows that engines of tested vehicles operate approximately at constant speed and load. The average temperature of exhaust gases is in the range from 300 to 400 °C for maximum gas mass flows of 1100 kg/h and 1400 kg/h for tractor and excavator engine respectively. Preliminary tests show that application of TEGs in tested off-road vehicles offers much more beneficial conditions for waste heat recovery than in case of automotive engines.

A gas distributor for distributing high temperature reaction gases to a fluidized bed of coal particles in a coal gasification process. The distributor includes a pipe with a refractory reinforced lining and a plurality of openings in the lining through which gas is fed into the bed. These feed openings have an expanding tapered shape in the downstream or exhaust direction which aids in reducing the velocity of the gas jets as they enter the bed.

Diesel engines have a wide range of uses which has led to increased requirements for petroleum derived from fossil fuel. The depletion of fossil fuel and the impact of increasing environmental pollution from exhaust gas emissions have led the search for alternative fuels. To solve the concerns of both energy and environment, renewable energies with lower environmental pollution impact are necessary. The focus on renewable energy and alternative fuels has increased due to increased oil prices, environmental pollution, and also concern for preserving nature. Biodiesel is known as an attractive alternative fuel although biodiesel produced from edible oil is more expensive than conventional diesel. Therefore, the use of biodiesel produced from non-edible oils is a much better option. Currently Jatropha biodiesel is receiving attention as an alternative fuel for diesel engines. Previous studies reported that Jatropha biodiesel was found to emit higher nitrogen oxides and lower smoke emissions compared to ordinary diesel. Exhaust gas recirculation is an effective technique to reduce nitrogen oxides emission from diesel engines because it enables lowering of both flame temperature and oxygen concentration in the combustion chamber. Some studies succeeded to reduce nitrogen oxides emission from biodiesel fuelled engines using exhaust gas recirculation. However, they observed an increase in soot emission. The aim of this study was to investigate the optimum trade-off between reduction in nitrogen oxides and increase in soot emissions using exhaust gas recirculation for a compression ignition engine fuelled with Jatropha based biodiesel. A 4-cylinder, water-cooled, turbocharged, indirect injection diesel engine was used for investigation. Exhaust emission characteristics were recorded and various engine performance parameters were also evaluated. The results showed that, at 5% exhaust gas recirculation rate along with Jatropha biodiesel blend effectively reduced both nitrogen oxides and soot emission by 27 and 11.3%, respectively, compared to diesel fuel without exhaust gas recirculation.

The environment impact of air traffic and economical aspects require aircraft engines to be developed which have reduced trace gas emissions and, at the same time, increased efficiency. Each new engine must be shown to meet the environmental requirements laid down by regulatory bodies, and exhaust gas measurements must be performed for the certification. The goal of the EC project AEROJET is to demonstrate the equivalence of remote measurement techniques to conventional extractive methods for both gaseous and particulate measurements. The different remote measurement techniques will be compared and calibrated. A demonstrator measurement system for exhaust gases, temperature and particulates including data-analysis software will be regarded as result of this project.

The reduction of oxides of nitrogen (NO(x)) emissions from aircraft gas turbine engines is a vital part of the NASA High Speed Research Program. Emissions reductions are critical to the feasibility of future High Speed Civil Transports which operate at supersonic speeds in the stratosphere. It is believed that large fleets of such aircraft using conventional gas turbine engines would emit levels of NO(x) that would be harmful to the stratospheric ozone layer. Previous studies have shown that NO(x) emissions can be reduced from stationary powerplant exhausts by the addition of additives such as ammonia to the exhaust gases. Since the exhaust residence times, pressures and temperatures may be different for aircraft gas turbines, a study has been made of additive effectiveness for high speed, high altitude flight.

In this paper, the potential of recovering waste heat from the fryer section and exhaust stream sent to the stack of a typical potato crisps or chips manufacturing plant and using the heat to drive an Organic Rankine Cycle (ORC) system for power generation has been presented. Five different ORC system Options (A, B, C, D and E) were considered. The first two options (A and B) make use of the waste heat from the foul gas and exhaust to stack respectively for power generation using a single ORC system each while the third option (option C) makes use of a novel dual heat source single ORC system where the low temperature waste heat from the foul gas is used to provide preheating and the high temperature waste from the exhaust to the stack used to provide the evaporation. Option D also shows a...

Objectives of this paper: To evaluate performance, combustion and emission of various blends of biodiesel (B20). Corn Oil, Palm Oil, Cotton Seed Oil, Various parameters, Brake Thermal Efficiency, Brake Specific Fuel Consumption, Brake Mean Effective Pressure, Instantaneous Heat Release, Cumulative Heat Release, Exhaust Gas Temperature, CO, CO2, HC, NOx, O2 and Smoke Intensity, To Compare with Diesel

In the course of the development of gas turbines for gas and steam turbine power stations (so-called gas/steam installations) providing ever more powerful types, new designs appeared for the subsequent exhaust gas ducting. The various manufacturers applied quite different design solutions to deal with the large cross-sections (several square meters) and the high operating temperatures in the exhaust gas ducts - with the compensators and their internal lining appearing as weak points. (orig.) [German] Im Verlauf der Weiterentwicklung von Gasturbinen fuer Gas- und Dampfkraftwerke (sog. GuD-Anlagen) zu immer leistungsstaerkeren Typen kam es zu Neukonstruktionen der anschliessenden Abgasfuehrung. Die jeweiligen Hersteller gelangten zu recht unterschiedlichen konstruktiven Loesungen fuer die mehrere Quadratmeter grossen Querschnitte und die hohen Betriebstemperaturen in den Abgaskanaelen, wobei sich die Kompensatoren und ihre Innenverkleidung als Schwachstellen herausstellten. (orig.)

A facility for exhaust gas recycling regarding diesel engines is described in which an exhaust gas filter for the recircled exhaust gas is arranged in an exhaust gas recycling circuit branching from the exhaust gas circuit. The insert of the exhaust gas filter in the branch-off point of the exhaust gas recirculation circuit is arranged in a way that its surface on the side of the sewage lies almost parallel to the flow direction of the main exhaust gas flow in the area and course of a normal flow line near to the wall. In a preferred type of design the insert of the filter consists of a shape stabil porous pipe made of sintered ceramics or sintered metal.

A roller bearing for an exhaust gas turbo-supercharger consists of two roller bearings arranged on a shaft at a distance from each other. High temperatures occur on one side of the shaft. Accurate bearing insensitive to high temperatures is achieved by means of an outer ring which is one-piece and a widened inner ring which is divided. The inner ring, which is adjacent to the high temperatures, is made of a material with high heat resistance.

A hybrid pneumatic power system (HPPS) is integrated by an internal combustion engine (ICE), a high efficiency turbine, an air compressor and an energy merger pipe, which can not only recycle and store exhaust gas energy but also convert it into useful mechanical energy. Moreover, it can make the ICE operate in its optimal state of maximum efficiency; and thus, it can be considered an effective solution to improve greatly the exhaust emissions and increase the overall energy efficiency of the HPPS. However, in this system, the flow energy merger of both high pressure compressed air flow and high temperature exhaust gas flow of the ICE greatly depends on the merging capability of the energy merger pipe. If the compressed air pressure (P{sub air}) at the air inlet is too high, smooth transmission and mixture of the exhaust gas flow are prevented, which will interfere with the operation condition of the ICE. This shortcoming is mostly omitted in the previous studies. The purpose of this paper is to study the effect of the level of P{sub air} and the contraction of cross-section area (CSA) at the merging position on the flow energy merger and determine their optimum adjustments for a better merging process by using computation fluid dynamics (CFD). In addition, the CFD model was validated on the basis of the experimental data, including the temperature and static pressure of the merger flow at the outlet of the energy merger pipe. It was found that the simulation results were in good agreement with the experimental data. The simulation results show that exhaust gas recycling efficiency and merger flow energy are significantly dependent on the optimum adjustment of the CSA for changes in P{sub air}. Under these optimum adjustments, the exhaust gas recycling efficiency can reach about 83%. These results will be valuable bases to research and design the energy merger pipe of the HPPS. (author)

When catalytic converters are used for cleansing of exhaust gas from two-stroke marine engines, new issues must be brought up in combination with prior technology. Therefore, a study was made of V6, 2600cc engine having a large volume of hydrocarbon emissions with respect to three issues: (1) To what degree seawater effects catalytic converter performance and possible countermeasures; (2) Effects attained on cleansing level and catalyst temperature; (3) Finding abatement levels for catalyst deterioration and exhaust emission output in the marine mode. It was found that physical adsorption was a significant factor in catalytic degradation resulting from direct contact with seawater. The cleansing levels obtained when a marine engine is equipped with a catalyst converter were found by clarifying the extent of effects of catalyst volume, performance and temperature. The reduction obtained in exhaust emission allowing for a deterioration factor, is shown in a catalytic converter heated to the maximum temperature of 960 C.

The objective of this program was to evaluate the merits of using natural gas-fired gas turbine exhaust to directly dry food products. A survey of drying practices utilized in the food industry and a detailed review of worldwide regulatory drying practices were completed. An investigation of the economic advantages associated with direct drying was also considered. Four drying scenarios were used as part of the analysis: Dilution - hot turbine exhaust gases were diluted with ambient air to achieve temperatures suitable for food product drying; Indirect Heat Exchanger - gas turbine exhaust was directed through an intermediate heat exchanger to avoid flue-gas contamination of the ambient air; Tri-Generation - exhaust gases from the gas turbine were first directed to a heat recovery boiler and then through the drying system to dry the food product; and Conventional Cogeneration - the most conventional simple cycle gas turbine cogeneration (this scenario served as the baseline for all evaluations). Although the economics associated with direct drying appear attractive, the principal concern of any potential use would be the extraordinarily high NO/sub x/ levels and the potential nitrate and nitrosamine (potential carcinogens and carcinogenic precursors) contamination in food products. 21 refs., 21 figs., 17 tabs.

A naturally aspirated multi cylinder diesel genset (DG) was operated successfully with mixed fuels (fossil-diesel (FD), refined rice bran oil (RRBO) and producer gas from a wood gasifier). Performance of DG set in FD, dual fuel mode (FD+RRBO in different proportion and FD+producer gas) and mixed fuels mode (with preheated blend of 75% RRBO+FD and producer gas) at different engine load conditions are presented in this paper. Performance of DG was evaluated in terms of specific energy consumption (SEC), brake thermal efficiency, exhaust gas temperature and exhaust gas composition. Study revealed that blends containing up to 75% RRBO with FD could be used as engine fuel without any adverse effect on the engine. The blend of RRBO and FD was preheated to 60degreeC before use in the compression ...

An experimental study is conducted to evaluate and compare the use of a diesel fuel supplement, specifically a 25/75% and a 50/50% blend of waste olive oil and commercial diesel fuel, in a four-stroke, DI (Direct Injection) diesel engine and in a four-stroke, IDI (Indirect Injection) diesel engine having a swirl-combustion chamber. The influence of the blends (diesel fuel + olive oil), for a large range of loads, has been examined on fuel consumption, maximum pressure, exhaust temperature, exhaust smokiness and exhaust-gas emissions such as nitrogen oxides (NO[sub x]), hydrocarbons (HC) and carbon monoxide (CO). The differences in the measured performance and exhaust-emission parameters, from the baseline operation of either engine, are determined and compared. The study shows, for both the DI and IDI engines, a small penalty in specific fuel consumption, a moderate increase in exhaust smokiness and essentially unaltered maximum pressures and exhaust temperatures when using the blends. Also, for both the IDI and DI engines when using the blends, the study shows moderate decreases in emitted nitrogen oxides and increases in hydrocarbons as well as negligible increases in emitted carbon monoxide. Theoretical aspects of diesel engine combustion are used to aid the interpretation of the observed engines' behaviour. (Author).

An exhaust gas filter apparatus includes a particulate filter for collecting a particulate from an exhaust gas. The exhaust gas filter also includes a electromagnetic radiation resonator to heat a portion of the particulate to ignite the particulate and regenerate the particulate filter.

Although a solid oxide fuel cell combined with a gas turbine (SOFC-GT) has good performance, the temperature of exhaust from gas turbine is still relatively high. In order to recover the waste heat of exhaust from the SOFC-GT to enhance energy conversion efficiency as well as to reduce the emissions of greenhouse gases and pollutants, in this study a new combined cooling, heat and power (CCHP) system driven by the SOFC is proposed to perform the trigeneration by using ammonia-water mixture to recover the waste heat of exhaust from the SOFC-GT. The CCHP system, whose main fuel is methane, can generate electricity, cooling effect and heat effect simultaneously. The overall system performance has been evaluated by mathematical models and thermodynamic laws. A parametric analysis is also condu...

This paper explains concepts of aircraft engine afterburner, and describes history of afterburner study, and describe the result of major research items. An afterburner is located down stream of a fan, compressor, burner, and turbine in a jet engine. Its basic principle is that fuel is injected into turbine exhaust and fan air flows from an fuel injector, ignited by a spark plug using oxygen remaining in the exhaust gas flow, burned and flame-held by a flame stabilizer. The combustion gas of high temperature (1,700 to 1,800 {degree}c) thus generated is jetted out from an exhaust nozzle to increase the thrust. The prototype afterburner is featured by adoption of a mixed type fuel injection system that provides wide stable combustion range, and flame stabilizer with a scoop aimed at improving the ignition performance and combustion efficiency. A confirmation test verified smooth ignition and wide air to fuel ratio for stabilized combustion. 4 refs., 16 figs.

The present invention provides a method capable of evacuating gases at an exhaustion rate which varies depending on the kind of gases. For example, in a thermonuclear experimental device, a hydrogen gas exhaustion rate is determined to 0 and an exhaustion rate for other impure gases is made greater. Namely, a baffle plate is cooled to a temperature to a level at which the vapor pressure of gases to evacuate a baffle plate is required in a pump incorporating a baffle plate, for example, a cryopump or a sorption pump. In this case, the level of the vapor pressure required for evacuating the exhaustion gas ingredients is 1 x 10{sup -8} Torr or less, preferably, 1 x 10{sup -9} Torr. In a thermonuclear experimental device, a gas having a lower boiling point next to hydrogen is neon, but neon is scarcely present in natural world. Nitrogen has a lower boiling point next thereto, and if the temperature is lowered to such a level that the vapor pressure for evacuating gases such as nitrogen, and carbon monoxide, oxygen, fluorine, argon or methane having a boiling point at or lower than nitrogen is required. Then, evacuation rate sufficient for gases other than hydrogen gas can be obtained. (I.S.)

The project is focused on the development of an energy efficient aftertreatment system capable of reducing NOx and methane by 90% from lean-burn natural gas engines by applying active exhaust flow control. Compared to conventional passive flow-through reactors, the proposed scheme cuts supplemental energy by 50%-70%. The system consists of a Lean NOx Trap (LNT) system and an oxidation catalyst. Through alternating flow control, a major amount of engine exhaust flows through a large portion of the LNT system in the absorption mode, while a small amount of exhaust goes through a small portion of the LNT system in the regeneration or desulfurization mode. By periodically reversing the exhaust gas flow through the oxidation catalyst, a higher temperature profile is maintained in the catalyst bed resulting in greater efficiency of the oxidation catalyst at lower exhaust temperatures. The project involves conceptual design, theoretical analysis, computer simulation, prototype fabrication, and empirical studies. This report details the progress during the first twelve months of the project. The primary activities have been to develop the bench flow reactor system, develop the computer simulation and modeling of the reverse-flow oxidation catalyst, install the engine into the test cell, and begin design of the LNT system.

This paper explains firstly two types of oxygen sensor used to measure oxygen concentration in subject gases (such as exhaust gases). One is a sensor corresponding to an oxygen concentration cell provided with porous electrodes (consisting mainly of Pt) on front and rear sides of a solid electrolyte (consisting mainly of ZrO{sub 2}), which generates an electromotive force determined by a ratio of oxygen partial pressures (and of temperatures) between the subject gas coming into contact with respective electrodes and the reference gas (normally air). The other sensor utilizes a fact that the strength of a limit current generated by applying a voltage across the electrodes is proportional to the oxygen concentration in the subject gas. Secondly, the paper describes that controlling automotive exhaust gases uses a tertiary system which combines a tertiary catalyst with an oxygen sensor, and that the point of exhaust gas control using the tertiary system is the output of the said zirconia oxygen sensor that identifies precisely the air excess rate in the exhaust gas at an optimal state (a level the tertiary catalyst exhibits its function most effectively). 2 refs., 3 figs., 1 tab.

In this work, the chemical composition of the exhaust gas from domestic gas boiler has been analysed in the point of thermodynamics and CO sensor has been characterized. We proposed that the combustion condition can be estimated by the exhaust gas composition, i.e., the excess air ratio and combustion temperature can be calculated simply by the measurement of the O{sub 2} fraction and H{sub 2}/CO in the exhaust gas. By analyse the on site situation domestic boiler, the excess air ration is about 55 {approx} 110%. Therefor, the CO may be produced in domestic gas boiler by luminous(yellow) flames rapidly lose heat by radiation, turbulent flames may be partially quenched by the action of steep velocity gradients, and flames burning very close to a cold wall may be partially quenched by heat conductivity to the wall. The output voltage of CO sensor is lineally depend on the CO and H{sub 2} concentration. And the exhaust CO from boiler can be reduced by closed loop control with CO sensor. 4 refs., 6 figs., 3 tabs.

Research is reported on the development of sensors for gas turbine combustor applications that measure real-time gas temperature using near-infrared water vapor absorption and concentration in the combustor exhaust of trace quantities of pollutant NO and CO using mid-infrared absorption. Gas temperature is extracted from the relative absorption strength of two near-infrared transitions of water vapor. From a survey of the water vapor absorption spectrum, two overtone transitions near 1800 nm were selected that can be rapidly scanned in wavelength by injection current tuning a single DFB diode laser. From the ratio of the absorbances on these selected transitions, a path-integrated gas temperature can be extracted in near-real time. Demonstration measurements with this new temperature sensor showed that combustor instabilities could be identified in the power spectrum of the temperature versus time record. These results suggest that this strategy is extremely promising for gas turbine combustor control applications. Measurements of the concentration of NO and CO in the combustor exhaust are demonstrated with mid-infrared transitions using thermo-electrically cooled, quantum cascade lasers operating near 5.26 and 4.62 microns respectively. Measurements of NO are performed in an insulated exhaust duct of a C2H4-air flame at temperatures of approximately 600 K. CO measurements are performed above a rich H2-air flame seeded with CO2 and cooled with excess N2 to 1150 K. Using a balanced ratiometric detection technique a sensitivity of 0.36 ppm-m was achieved for NO and 0.21 ppm-m for CO. Comparisons between measured and predicted water-vapor and CO2 interference are discussed. The mid-infrared laser quantum cascade laser technology is in its infancy; however, these measurements demonstrate the potential for pollutant monitoring in exhaust gases with mid-IR laser absorption.

In this paper, an H~ robust controller has been designed for an identified model of MONTAZER GHAEM power plant gas turbine (GE9001E). In design phase, a linear model (ARX model) which is obtained using real data has been applied. Since the turbine has been used in a combined cycle power plant, its speed and also the exhaust gas temperature should be adjusted simultaneously by controlling fuel signals and compressor inlet guide vane (IGV) position. Considering the limitations on the system inputs, the aim of the control is to maintain the turbine speed and the exhaust gas temperature within desired interval under uncertainties and load demand disturbances. Simulation results of applying the proposed robust controller on the nonlinear model of the system (NARX model), fairly fulfilled the pr...

For turbochargers where an auxiliary exhaust gas duct is provided next to the main exhaust gas duct from the exhaust gas side of a turbine casing, there are problems regarding the tolerances to be complied with on the exhaust pipe. The manufacturing costs are also unavoidably increased. Furthermore, the connection of the exhaust pipe is complicated. Finally, the exhaust pipe itself becomes heavy. The purpose of the invention is therefore to create a turbo-supercharger, where an exhaust pipe which is commercially available can be used as the common exhaust pipe for the main exhaust duct and the auxiliary exhaust duct. This makes the manufacture of the exhaust pipe simpler, its weight is lowered, the exhaust pipe connection is made easier, the manufacturing costs are reduced and a satisfactory ejection operation of the main exhaust flow is ensured. A characteristic of the two patent claims is the formation of a single part annular exhaust pipe connection on the outlet side of the turbine case and the separating wall between the main exhaust duct and the auxiliary exhaust duct.

Recent in-flight measurements of aircraft engine exhaust have suggested much higher conversions of fuel sulfur to sulfuric acid aerosols than can be explained by gas-phase oxidation within the exhaust plume. This paper describes the effects of turbine and exhaust nozzle aerodynamics and chemical kinetics on the production of sulfate aerosol precursors in engine exhaust. Results from both one-dimensional (1-D) and two-dimensional (2-D) numerical simulations are presented for a range of flow and chemistry conditions. One-dimensional calculations for the entire postcombustor flow path of an advanced subsonic engine resulted in up to 6.3% sulfur oxidation through the turbine and exhaust nozzle. Results were most sensitive to species concentrations at the combustor exit, combustor exit temperature, and cooling flow mass addition in the turbine. Two-dimensional calculations for a representative turbine demonstrated that intraengine fluid mechanics can increase sulfur oxidation by a factor of 3 across a single blade row because of cooling-induced temperature nonuniformities. Comparisons of averaged 2-D results with 1-D simulations of the same blade row further showed that while 1-D simulations produce the correct trends, the magnitude of change in sulfur oxidation may be underpredicted by as much as 47% over a single blade row if spatial nonuniformities in flow field temperature are not included.

A combination acoustical muffler and exhaust converter for use with internal combustion engines, comprising an elongated hollow cylinder adapted to be connected to a source of exhaust gas, screen means positioned at a plurality of longitudinally spaced locations within said cylinder for partitioning the cylinder into a plurality of chambers arranged in series flow relation with each other and with respect to the flow of exhaust gas through said cylinder, the screens having a silencing action on said exhaust gas, magnet means in one of said chambers for exerting a magnetic pressure on the gas passing therethrough to serve to separate ferrous particles from the exhaust gas stream, a packing material of mineral material, such as mineral wool, in another of said chambers for condensing moisture in said exhaust gas and for removing hydrocarbon therefrom, and a material such as a ceramic material of an extremely fine porous nature, in still another of said chambers for removing carbon monoxide from said exhaust gas.

A series of pressurization smoke control experiments were conducted using a fire room [2. 7 m × 3. 6 m × 1. 18 m (height)] of two-fifths reduced scale model for examining air supply conditions necessary to prevent smoke efflux from a fire room. For understanding the prediction of the critical air velocity to prevent smoke backflow under pressurization smoke control, the temperature of the hot layer formed in a fire room shall be well-assessed. Therefore, the temperature of the hot layer in a fire room and the waste gas of the exhaust were measured for constructing equations for simple prediction. In case of pressurization smoke control, the algebraic simple equation on the temperature of the hot layer in a fire room at unsteady state is proposed in consideration of the heat loss by the waste gas of the exhaust based on these experimental data.   

Combined cycle configuration has the ability to use the waste heat from the gas turbine exhaust gas using the heat recovery steam generator for the bottoming steam cycle. In the current study, a natural gas-fired combined cycle with indirectly fired heating for additional work output is investigated for configurations with and without reheat combustor (RHC) in the gas turbine. The mass flow rate of coal for the indirect-firing mode in circulating fluidized bed (CFB) combustor is estimated based on fixed natural gas input for the gas turbine combustion chamber (GTCC). The effects of pressure ratio, gas turbine inlet temperature, inlet temperatures to the air compressor and to the GTCC on the overall cycle performance of the combined cycle configuration are analysed. The combined cycle effic...

A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

This patent describes a method for disposing of water produced by a gas well assembly, which gas well assembly includes a gas compressor which produces hot exhaust and a muffler for muffling the noise of the exhaust from the gas compressor. It comprises: circulating the water in heat exchange relation with the hot exhaust under conditions permitting the water to vaporize, wherein such circulation is carried out in a vessel through which a conduit carrying the hot exhaust is submerged; venting steam produced by such circulation; and feeding a stream of hot exhaust from the muffler through the vessel for promoting the venting of steam from the vessel.

This patent describes an apparatus for separating volatile organic compounds from a stream of gas. It comprises an internal combustion engine including a rotating shaft; an inert gas generating means for converting at least a portion of exhaust from the internal combustion engine into an inert gas and mixing the inert gas into the stream of gas; heat transfer means for recovering waste heat from the internal combustion engine to heat a portion of the stream of gas; a first and a second refrigeration system operatively connected to the rotating shaft of the internal combustion engine, the first and the second refrigeration systems operating at substantially different temperatures, the first and second refrigeration systems receiving the stream of gas and cooling the stream of gas thereby extracting the volatile organic compounds therefrom.

Alternative fuels for diesel engines, such as biodiesel, have attracted much attention recently due to increasing fuel prices and the imperative to reduce emissions. The exhaust gas emissions from tractors and other agricultural machinery make a significant contribution to these emissions. The use of biodiesel in internal combustion engines (ICE) has been reported to give comparable performance to conventional diesel (CD), but with generally lower emissions. There is however, contradictory evidence of NO emissions being both higher and lower from the use of biodiesel. In this work, agriculture tractor engine performance and its emission using both CD and biodiesel from cotton seed oil (CSO-B20) mixed at a 20% blend ration has been evaluated and compared. The PTO test results showed comparable exhaust emissions between CD and CSO-B20. However, the use of CSO-B20 led to reductions in the thermal efficiency and exhaust temperature and an increase in the brake specific fuel consumption (BSFC), when compared to CD.

In the dry analytical method of formaldehyde in automobile exhaust emission, sampling conditions such as temperature and flow rate, and measurable concentration ranges were examined. Silicagel cartridges coated with 2,4-dinitrophenylhydrazin (DNPH) were prepared, and a prototype gas sampling system was fabricated to sample by both conventional impinger method and the cartridge method at the same time, and a high performance liquid chromatograph was used for analysis. As a result, since a collection efficiency reached 100% at 70 {degree} C in a high formaldehyde concentration range over 10ppm, it was necessary to heat a sampling line. As heated, formaldehyde was fully collected independently of moisture in exhaust emission, and a sampling rate of 0.5l/min was also desirable. The measurable concentration range entirely covered that of formaldehyde in exhaust emission, and a measurement accuracy was also equivalent to that of the impinger method. 4 refs., 7 figs., 4 tabs.

The most part of energy losses in power system such as fuel cells is due to the heat released by the exhaust gas to atmosphere. The exhaust gas consists of non-condensable gas and steam with sensible and latent heat. As a lot of latent heat is included in the exhaust gas, its recovery is very important to improve the power system efficiency. Based on the previous basic studies, a thermal hydraulic prediction method for latent heat recovery exchangers was proposed. For the condensation of steam on heat transfer tubes, the modified Sherwood number taking account of the mass absorption effect on the wall was used. Two kinds of compact heat exchanger with staggered banks of bare tubes of 10.5 or 4mm in outer diameter was designed with the prediction method. The more compactness was obtained with the smaller tubes at a designed heat recovery. The thermal hydraulic behavior in the compact heat exchangers was experimentally studied with air-steam mixture gas. In the parametric experiments varying the steam mass concentration, the temperature distributions of cooling water and mixture gas were measured. The experimental results agreed well with the prediction proposed in this study and the more compactness with the smaller tubes was proved.   

The paper presents a novel control-oriented, first-principle model of a three-way catalytic converter (TWC). The model accurately predicts the air-fuel ratio downstream of the catalyst and provides insights into the relative oxygen level (ROL) profile along the catalyst. The reaction mechanism of the TWC model is simplified to only two reactions, with oxygen being the only species stored on the active surface of the catalyst. All the information about the gas composition is taken from the upstream wide-range oxygen sensor. Additional model inputs are the exhaust gas temperature and the exhaust mass flow. The model is parameterized with only a few measurements from an engine test bench. Exact values of gas concentrations are not needed at any point. The ROL profile is a good indicator for t...

Jojoba methyl ester (JME) has been used as a renewable fuel in numerous studies evaluating its potential use in diesel engines. These studies showed that this fuel is good gas oil substitute but an increase in the nitrogenous oxides emissions was observed at all operating conditions. The aim of this study mainly was to quantify the efficiency of exhaust gas recirculation (EGR) when using JME fuel in a fully instrumented, two-cylinder, naturally aspirated, four-stroke direct injection diesel engine. The tests were carried out in three sections. Firstly, the measured performance and exhaust emissions of the diesel engine operating with diesel fuel and JME at various speeds under full load are determined and compared. Secondly, tests were performed at constant speed with two loads to investigate the EGR effect on engine performance and exhaust emissions including nitrogenous oxides (NO{sub x}), carbon monoxide (CO), unburned hydrocarbons (HC) and exhaust gas temperatures. Thirdly, the effect of cooled EGR with high ratio at full load on engine performance and emissions was examined. The results showed that EGR is an effective technique for reducing NO{sub x} emissions with JME fuel especially in light-duty diesel engines. With the application of the EGR method, the CO and HC concentration in the engine-out emissions increased. For all operating conditions, a better trade-off between HC, CO and NO{sub x} emissions can be attained within a limited EGR rate of 5-15% with very little economy penalty. (author)

In order to comply with the increased requirements of the legislature 2 lime shaft kilns in a Sauerland lime plant were equipped with a reverse-jet fabric filter. The dust in the crude gas from the kilns, which are fired with a variety of fuels, contained constituents from the fuel and impurities from the limestone in addition to the predominant calcium carbonate and calcium oxide. The dedusting system is adapted to suit the changing operating conditions such as starting and stopping, and one- and two-kiln operation with various fuels. The operating temperature required for Nomex needle felt of 180deg C is maintained by cooling the kiln exhaust gas with exhaust air from the lime silo or with fresh air. The plant is designed so that it can deal with corrosion, temperature fluctuations and changing operating conditions. The emission limit of less than 50 mg/m{sup 3} required by the Clean Air Technical Code is met during continuous operation. (orig.).

A theoretical study is conducted to investigate the potential improvement of the overall efficiency of a heavy-duty truck diesel engine equipped with a Rankine bottoming cycle for recovering heat from the exhaust gas. To this scope, a newly developed thermodynamic simulation model has been used, considering two different working media: water and the refrigerant R245ca. As revealed from the analysis, due to the variation of exhaust gas temperature with engine load it is necessary to modify the Rankine cycle parameters i.e. high pressure and superheated vapor temperature. For this reason, a new calculation procedure is applied for the estimation of the optimum Rankine cycle parameters at each operating condition. The calculation algorithm is conducted by taking certain design criteria into a...

Project is focused on fast time-resolved infrared measurements of gas temperature and fast IR-imagining of flames in various combustion environments. The infrared spectrometer system was developed in the project for fast infrared spectral measurements on industrial scale using IR-fibre- optics. Fast time-and spectral-resolved measurements in 1.5-5.1 mu spectral range give information about flame characteristics like gas and particle temperatures, eddies and turbulent gas mixing. Time-resolved gas composition in that spectral range (H{sub 2}O, CH{sub 4}, CO{sub 2}, CO) which is one of the key parameters in combustion enhancement can be also obtained. The infrared camera was also used together with special endoscope optics for fast thermal imaging of a coal-straw flame in an industrial boiler. Obtained time-resolved infrared images provided useful information for the diagnostics of the flame and fuel distribustion. The applicability of the system for gas leak detection is also demonstrated. The infrared spectrometer system with minor developments was applied for fast time-resolved exhaust gas temperature measurements performed simultaneously at the three optical ports of the exhaust duct of a marine Diesel engine and visualisation of gas flow behaviour in cylinder. (Author)

A chemical mechanism for the reduction of NO{sub x} by HNCO has been constructed to allow for the modeling of NO{sub x} in exhausts typical of natural gas combustion (RAPRENOx process). The reduction was modeled assuming plug flow, and either isothermal combustion or constant pressure adiabatic combustion. Variables were initial concentrations of NO, NO{sub 2}, CO, CH{sub 4}, H{sub 2}, and HNCO as well as initial temperatures. Exhaust residence time was nominally 1 s. Reduction was not achieved for prototypical ``natural gas exhaust`` for a reasonable residence time. Radical generation is crucial for reduction. H{sub 2} addition enhanced ignition and reduction. The final combustion temperature determines where NO{sub x} reduction ceases and NO{sub x} production increases. Reduction increases with HNCO, and breakthrough of NH{sub 3} and HNCO increses as well. N{sub 2}O production is due to NCO + NO, but the reduction of NO also occurs through reactions associated with the Thermal De-NOx chemistry. NH{sub 3} production and reactions are important to the reduction of NO. Sensitivity analysis under easy ignition conditions indicated that the same reactions involving nitrogen species, NH{sub 2} and NNH, important in De-NOx, are important when HNCO is used to reduce NO{sub x}. A real combustion exhaust would contain radicals, but it would be neither isothermal nor adiabatic, and heat release and loss would accompany the reduction process. Three-body recombination reactions are important and need further study.(DLC)

Small stationary diesel engines, like in generator sets, have limited emission control measures and are therefore responsible for 44% of the particulate matter (PM) emissions in the United States. The diesel exhaust composition depends on operating conditions of the combustion engine. Furthermore, the measurements are influenced by the used sampling method. This study examines the effect of engine loading and exhaust gas dilution on the composition of small-scale power generators. These generators are used in different operating conditions than road-transport vehicles, resulting in different emission characteristics. Experimental data were obtained for gaseous volatile organic compounds (VOC) and PM mass concentration, elemental composition and nitrate content. The exhaust composition depends on load condition because of its effect on fuel consumption, engine wear and combustion temperature. Higher load conditions result in lower PM concentration and sharper edged particles with larger aerodynamic diameters. A positive correlation with load condition was found for K, Ca, Sr, Mn, Cu, Zn and Pb adsorbed on PM, elements that originate from lubricating oil or engine corrosion. The nitrate concentration decreases at higher load conditions, due to enhanced nitrate dissociation to gaseous NO at higher engine temperatures. Dilution on the other hand decreases PM and nitrate concentration and increases gaseous VOC and adsorbed metal content. In conclusion, these data show that operating and sampling conditions have a major effect on the exhaust gas composition of small-scale diesel generators. Therefore, care must be taken when designing new experiments or comparing literature results. PMID:16933642

The feed pipe of the exhaust gases from a combustion engine to the rotor of a centrifugal turbine of an exhaust gas turbo-supercharger consists of a system of pipes connecting the engine to the turbine case, where the turbine case has three radial outlets opening towards the rotor. With well-known feed pipes, variations of axial thrust of the exhaust gases entering the turbine adversely affect the efficiency. In order to improve the efficiency, half of the cylinders of the engine have the first exhaust gas pipe and the other half of the cylinders have the second exhaust gas pipe connected to them. Further, the first exhaust gas pipe is connected to the central of the three outlets of the turbine case, and the second exhaust gas pipe is connected by two pipes to the two outer of the three outputs of the turbine case.

Biofuels are coming up as an ecological alternative solution to fossil fuels. This article describes an emulsification method which allows to transform an animal fat into a biofuel for the supply of a cogeneration diesel engine: formation of the emulsion (material and method, wetting agent, co-wetting agent, rotation speed); combustion of emulsions (micro-explosion effect, influence of water content); experimental results (energy efficiency, exhaust gas temperature, pollutant emissions (smokes, nitrogen oxides)). (J.S.)

Objectives are to develop actuators for enhancing the mixing between gas streams, increase combustion stability, and develop hgih-temperature materials for actuators and sensors in combustors. Turbulent kinetic energy maps of an excited jet with co-flow in a cavity with a partially closed exhaust end are given with and without a longitudinal or a transverse acoustic field. Dielectric constants and piezoelectric coefficients were determined for Sr{sub 2}(Nb{sub x}Ta{sub 1-x}){sub 2}O{sub 7} ceramics.

A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

Under Sandia`s Laboratory Directed Research and Development (LDRD) program, novel acoustic wave-based sensors were explored for detecting gaseous chemical species in vehicle exhaust streams. The need exists for on-line, real-time monitors to continuously analyze the toxic exhaust gases -- nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons (HC) -- for determining catalytic converter efficiency, documenting compliance to emission regulations, and optimizing engine performance through feedback control. In this project, the authors adapted existing acoustic wave chemical sensor technology to the high temperature environment and investigated new robust sensor materials for improving gas detection sensitivity and selectivity. This report describes one new sensor that has potential use as an exhaust stream residual hydrocarbon monitor. The sensor consists of a thickness shear mode (TSM) quartz resonator coated with a thin mesoporous silica layer ion-exchanged with palladium ions. When operated at temperatures above 300 C, the high surface area film catalyzes the combustion of the hydrocarbon vapors in the presence of oxygen. The sensor acts as a calorimeter as the exothermic reaction slightly increases the temperature, stressing the sensor surface, and producing a measurable deviation in the resonator frequency. Sensitivities as high as 0.44 (ppm-{Delta}f) and (ppm-gas) have been measured for propylene gas, with minimum detectable signals of < 50 ppm of propylene at 500 C.

A technique for producing thrust by generating a hybrid plume plasma exhaust is disclosed. A plasma flow is generated and introduced into a nozzle which features one or more inlets positioned to direct a flow of neutral gas about the interior of the nozzle. When such a neutral gas flow is combined with the plasma flow within the nozzle, a hybrid plume is constructed including a flow of hot plasma along the center of the nozzle surrounded by a generally annular flow of neutral gas, with an annular transition region between the pure plasma and the neutral gas. The temperature of the outer gas layer is below that of the pure plasma and generally separates the pure plasma from the interior surfaces of the nozzle. The neutral gas flow both insulates the nozzle walls from the high temperatures of the plasma flow and adds to the mass flow rate of the hybrid exhaust. The rate of flow of neutral gas into the interior of the nozzle may be selectively adjusted to control the thrust and specific impulse of the device.

A power source is provided for use with selective catalytic reduction systems for exhaust-gas purification. The power source includes a first cylinder group with a first air-intake passage and a first exhaust passage, and a second cylinder group with a second air-intake passage and a second exhaust passage. The second air-intake passage is fluidly isolated from the first air-intake passage. A fuel-supply device may be configured to supply fuel into the first exhaust passage, and a catalyst may be disposed downstream of the fuel-supply device to convert at least a portion of the exhaust stream in the first exhaust passage into ammonia.

This paper introduces an automotive exhaust heat recirculation system. This system was developed to improve fuel economy after cold starts in the winter. The warm-up speed of the engine and heater performance can be improved by recovering exhaust heat from exhaust gas to the engine coolant. As a result, the actual fuel economy is improved due to earlier engine stops in hybrid vehicles.   

A homogeneous charge compression ignition engine is set up by first identifying combinations of compression ratio and exhaust gas percentages for each speed and load across the engines operating range. These identified ratios and exhaust gas percentages can then be converted into geometric compression ratio controller settings and exhaust gas recirculation rate controller settings that are mapped against speed and load, and made available to the electronic

Previous experimental studies on diesel engine have demonstrated the potential of exhaust gas recirculation (EGR) as an in-cylinder NOx control method. Although an increase in EGR at constant boost pressure (substitution EGR) is accompanied with an increase in particulate matter (PM) emissions in the conventional diesel high-temperature combustion (HTC), the recirculation of exhaust gases supplementary to air inlet gas (supplemental EGR) by increasing the boost pressure has been suggested as a way to reduce NOx emissions while limiting the negative impact of EGR on PM emissions. In the present work, a low-pressure (LP) EGR loop is implemented on a standard 2.0 l automotive high-speed direct injection (HSDI) turbocharged diesel engine to study the influence of high rates of supplemental coo...

We have investigated the performance of dual metal oxide electrode mixed potential sensors in an engine-out, dynamometer environment. Sensors were fabricated by sputtering thin films of LaMnO{sub 3} and Tb-doped YSZ onto YSZ electrolyte. Au gauze held onto the metal oxide thin films with Au ink was used for current collection. The exhaust gas from a 4.8L, V8 engine operated in open loop, steady-state mode around stoichiometry at 1500 RPM and 50 Nm. The sensor showed a stable EMF response (with no hysteresis) to varying concentrations of total exhaust gas HC content. The sensor response was measured at 620 and 670 C and shows temperature behavior characteristic of mixed potential-type sensors. The results of these engine-dynamometer tests are encouraging; however, the limitations associated with Au current collection present the biggest impediment to automotive use.

This paper presents theoretical and experimental results of exhaust gas reforming of gasoline at lower reformer temperatures (650 and 600{sup o}C). The reformed fuel, containing some quantities of hydrogen and carbon monoxide, was fed at a constant rate to the intake manifold of a single cylinder Ricardo E6 engine as an additive to gasoline. The study of the effects of reformed gas addition on engine performance at extreme lean burn conditions was performed at fixed conditions of speed, load and throttle setting, for different ignition timing settings. Results are encouraging in terms of improved engine deficiency and extended lean burn operation for most ignition timings, despite quite low hydrogen content in the reformed fuel which resulted in low proportions of energy input to the engine from the reformed fuel. Also the levels of pollutant exhaust contents (NO{sub x} and HC) were lower and cycle-to-cycle variations of cylinder pressure was reduced. (author)

Regarding gaseous exhaust gas components the diesel engine represents the most advantageous combustion engine. Although, the high degree of emission of particles consisting of soot, with attached hydrocarbons sulfates and being in part considered to be mutagenic, remains. The influence of the quality of diesel fuel upon the emission of particles from Heavy Duty-diesel engines, is being investigated. In the low level load range, distinct HC-particle and PAH-emissions have been found to increase with decreasing cetane numbers. Cold start tests have indicated that with decreasing cetane numbers the starting and cold run behaviour of diesel engines is definitely impeded. When, by means of ignition-improver, the cetane number is increased, the achieved improvement of the cold start is (in part) not as high as one would expect from the higher cetane number. When exhaust gas temperatures become as high as above approx. 200deg C, oxidizing catalysts contribute to a distinct reduction of the hydrocarbons that are attached to the soot and thus, to the emission of particles. The influence of the sulphate, being contained in the fuel, upon the sulphate emission in the application (employment) of the oxidizing catalyst at high exhaust gas temperatures, will be discussed (in a graph/diagram). (orig./HW).

The invention is concerned with a multi-flow exhaust gas turbocharger for internal combustion engines of automobiles. The turbocharger is equipped with a radial-turbine wheel, a helical shaped exhaust gas inlet pipe and a system for controlling the turbine operation in relation to the operation conditions of the engine for achieving a optimal performance. If the engine load is high, a partial volume of the exhaust gas flows through a bypass outside the turbine wheel. This bypass channel is located on the case of the turbine, provided with ring slit apertures for the flow connection to the helical exhaust gas inlet.

This computer program calculates the temperature profile of a flame or hot gas. Emphasis is on profiles found in jet engine or rocket engine exhaust streams containing water vapor or carbon dioxide as radiating gases. The temperature profile is assumed to be axisymmetric with a functional form controlled by two variable parameters. The parameters are calculated using measurements of gas radiation at two wavelengths in the infrared spectrum. Infrared emission and absorption measurements at two or more wavelengths provide a method of determining a gas temperature profile along a path through the gas by using a radiation source and receiver located outside the gas stream being measured. This permits simplified spectral scanning of a jet or rocket engine exhaust stream with the instrumentation outside the exhaust gas stream. This program provides an iterative-cyclic computation in which an initial assumed temperature profile is altered in shape until the computed emission and absorption agree, within specified limits, with the actual instrument measurements of emission and absorption. Temperature determination by experimental measurements of emission and absorption at two or more wavelengths is also provided by this program. Additionally, the program provides a technique for selecting the wavelengths to be used for determining the temperature profiles prior to the beginning of the experiment. By using this program feature, the experimenter has a higher probability of selecting wavelengths which will result in accurate temperature profile measurements. This program provides the user with a technique for determining whether this program will be sufficiently accurate for his particular application, as well as providing a means of finding the solution. The input to the program consists of four types of data: (1) computer program control constants, (2) measurements of gas radiance and transmittance at selected wavelengths, (3) tabulations from the literature of gas transmission parameters at selected wavelengths, and (4) independently determined or estimated profiles of partial pressures of the gas reaction products. The output consists of error figures for the temperature and partial pressure profiles in tabular form. This program is written in FORTRAN IV for execution on an UNIVAC 1100 series computer with a main memory requirement of 21K of 36 bit words. This program was developed in 1977.

Laser-induced breakdown spectroscopy (LIBS) was used in the evaluation of aerosol concentration in the exhaust of an oxygen/natural-gas glass furnace. Experiments showed that for a delay time of 10 {micro}s and a gate width of 50 {micro}s, the presence of CO{sub 2} and changes in gas temperature affect the intensity of both continuum emission and the Na D lines. The intensity increased for the neutral Ca and Mg lines in the presence of 21% CO{sub 2} when compared to 100% N{sub 2}, whereas the intensity of the Mg and Ca ionic lines decreased. An increase in temperature from 300 to 730 K produced an increase in both continuum emission and Na signal. These laboratory measurements were consistent with measurements in the glass furnace exhaust. Time-resolved analysis of the spark radiation suggested that differences in continuum radiation resulting from changes in bath composition are only apparent at long delay times. The changes in the intensity of ionic and neutral lines in the presence of CO{sub 2} are believed to result from higher free electron number density caused by lower ionization energies of species formed during the spark decay process in the presence of CO{sub 2}. For the high Na concentration observed in the glass furnace exhaust, self-absorption of the spark radiation occurred. Power law regression was used to fit laboratory Na LIBS calibration data for sodium loadings, gas temperatures, and a CO{sub 2} content representative of the furnace exhaust. Improvement of the LIBS measurement in this environment may be possible by evaluation of Na lines with weaker emission and through the use of shorter gate delay times.

This patent describes an engine muffler responsive to exhaust flow rate for an internal combustion engine. It comprises: a body forming an internal expansion chamber and having an inlet port and an exhaust port spaced apart from one another, to receive and to discharge exhaust gas stream, respectively, and a variable restrictor downstream from the inlet port and upstream from the outlet port, through which the exhaust gas stream must flow to reach the exhaust port. The variable restrictor including a valving element whose operative position can variably occlude the gas stream flow as a function of engine exhaust flow rate. Wherein the variable restrictor is formed with a solid wall disposed about the valving element to define a constricting annular passageway having a cross section that varies with distance from the inlet port and from the exhaust port.

Apparatus is described for detecting motor vehicle exhaust gas catalytic converter deterioration comprising a first exhaust gas oxygen sensor adapted for communication with an exhaust stream before passage of the exhaust stream through a catalytic converter and a second exhaust gas oxygen sensor adapted for communication with the exhaust stream after passage of the exhaust stream through the catalytic converter, an on-board vehicle computational means, said computational means adapted to accept oxygen content signals from the before and after catalytic converter oxygen sensors and adapted to generate signal threshold values, said computational means adapted to compare over repeated time intervals the oxygen content signals to the signal threshold values and to store the output of the compared oxygen content signals, and in response after a specified number of time intervals for a specified mode of motor vehicle operation to determine and indicate a level of catalyst deterioration.

The system, retrofitted to an existing bulk curing barn, successfully cured tobacco and required about the same amount of fuel energy input as oil or gas fired barns. Fire box temperatures were in the 900C (1600F) range and no difficulty was experienced in burning fresh (43% moisture) chips. The exhaust was clear and no cresote deposits were found, but because of the large amount of excess combustion air, overall efficiency was not as high as expected. At present prices, wood chips are a significantly cheaper fuel than gas or oil.

The present invention provides a process for catalytically reducing nitrogen oxides in an exhaust gas stream containing nitrogen oxides and a reductant material by contacting the gas stream under conditions effective to catalytically reduce the nitrogen oxides with a catalyst comprising a aluminum-silicate type material and a minor amount of a metal, the catalyst characterized as having sufficient catalytic activity so as to reduce the nitrogen oxides by at least 60 percent under temperatures within the range of from about 200.degree. C. to about 400.degree. C.

Recent diesel engine technologies, developed for enhanced regulation of exhaust emissions, are characterized by high exhaust gas recirculation (EGR) rates and high-pressure fuel injection. The use of high EGR rates, by which high temperatures can be avoided in a cylinder, is an effective method for reduction of nitrogen oxide (NO x ) emissions. High-pressure fuel injection leads to smaller soot particles, which decreases mass-based soot emission. These technologies, however, also have effects on particulate matter (PM) characteristics that are closely related to EGR cooler fouling. High-pressure fuel injection, which makes smaller soot particles, increases the concentration of soot particles, and a high EGR rate, which lowers the temperature in the cylinder, increases the soluble organic fraction (SOF). In this study, we evaluated the effects of these changes in PM characteristics on EGR cooler fouling. Instead of an engine-based experiment, in which a parametric study is nearly impossible, a laboratory experiment was performed to separate variables. A soot generator was used to make model exhaust gas because the variables could be controlled separately (e.g., mean particle size and concentration of soot particles) and this improved the reproducibility of the experiments. Additionally, n-dodecane, a model compound representing diesel fuel, was vaporized and injected into the exhaust gas to test the effects of SOF on cooler fouling. For particle sizes ranging from 41 to 190 nm in diameter, the deposition fraction was inversely proportional to particle size. Thus, smaller soot particles in the exhaust gas were more likely to cause formation of thermophoretic deposits on the wall of the EGR cooler. At an EGR gas temperature of 350 °C, the deposition fraction was greatest (84%) for the smallest particle size of 41 nm, whereas the deposition fraction was least (7%) for the largest particle size, 190 nm. The performance degradation of the EGR cooler showed a similar trend to the measured deposit mass. As coolant temperature decreased, the effect of n-dodecane injection on the growth of PM deposits increased, which significantly reduced the overall thermal conductivity of the EGR cooler. This result showed that 'wet soot' caused greater contamination of the EGR cooler.

A light duty truck with a naturally aspirated engine was equipped with a DPF (changing the exhaust pipe and eliminating the muffler) and operated on fuel doped with a cerium based additive in various concentrations. Tests were carried out on chassis dynamometer using the European urban cycle, but also under city driving conditions with maximum speeds up to 50 km/h and exhaust gas temperature up to 300 C. Under these conditions, it was observed that filter regeneration was always possible at relatively high particulate accumulation in the filter, while the effect on fuel consumption (as measured over the emission test cycles) was not detectable, compared to baseline data of the vehicle. Change in driving conditions from slow urban to highway with highly loaded trap led to spontaneous trap regeneration at higher temperatures, without effect on fuel consumption. This paper documents the operation of a fully passive DPF system for diesel light duty vehicles.

A heterogeneous model is developed for the regeneration of the Cr2O3/Al2O3 catalyst for the propane dehydrogenation process by considering the internal mass transfer and external mass/heat transfer during the coke combustion. Simulation shows that under practical operating conditions, multi-steady states exist for the catalyst pellets and the catalyst temperature is sensitive to gas temperature. However, at increased mass flow rate or lowered oxygen concentration, multi-steady states will not appear. Under the strong influences of film diffusion, the coke in the packed bed reactor will first be exhausted at the inlet, while if the film diffusion resistance is decreased, the position of first coke exhaustion moves toward the outlet of the reactor.

This invention relates to the coal gasification system, wherein coal and superheated steam are supplied to a steam gasifier which utilizes high temperature helium of the high temperature gasifier, which is a graphite-moderated helium cooling reactor, to produce coal gasified gas by steam gasification reaction. This coal gasifier system employs the primary helium gas and the secondary helium gas as media, and is structured by combining a steam gasifier, which utilizes the heat of the high temperature gasifier fully, with a partial oxidation gasifier, which requires no outside heat input and is independent thermally by the use of calorie of the fuel itself. In this structure, unreacted char exhausted from the steam gasifier is recovered by the cyclone which is supplied to the juxtaposed partial oxidation gasifier for re-gasification, and high coal gasification efficiency can be attained as the whole coal gasification system utilizing the heat of graphite moderated helium cooling reactor. 4 figs.

The objective of this paper is to experimentally determine the efficiency and viability of the performance of an advanced trigeneration system that consists of a micro gas turbine in which the exhaust gases heat hot thermal oil to produce cooling with an air cooled absorption chiller and hot water for heating and DHW. The micro gas turbine with a net power of 28kW produces around 60kW of heat to drive an ammonia/water air-cooled absorption chiller with a rated capacity of 17kW. The trigeneration system was tested in different operating conditions by varying the output power of the micro gas turbine, the ambient temperature for the absorption unit, the chilled water outlet temperature and the thermal oil inlet temperature. The modelling performance of the trigeneration system and the electr...

The objective of this study is to design, set up and operate an incinerator system capable of providing clean exhaust and safety control for burning oil gas generated during the recovery process of oil spill in Taiwan. In this study, we successfully develop a vertical-type incinerator, which consists of five oil gas burners with entrained primary air, a pilot burner, and an auxiliary burner. The incinerator system is equipped with necessary control units in order to achieve safe, easy, fast, and efficient operation. Flame appearance, flue gas temperature and CO emission of the incinerator system for burning oil gas are reported and discussed. Under the long-term operation, it is found that the new designed incinerator is satisfactory for burning oil gas with low supply pressure at various ...

Flame chemiluminescence is widely acknowledged to be an indicator of heat release rate in premixed turbulent flames that are representative of gas turbine combustion. Though heat release rate is an important metric for evaluating combustion strategies in reciprocating engine systems, its correlation with flame chemiluminescence is not well studied. To address this gap an experimental study was carried out in a single-cylinder natural gas fired reciprocating engine that could simulate turbocharged conditions with exhaust gas recirculation. Crank angle resolved spectra (266-795 nm) of flame luminosity were measured for various operational conditions by varying the ignition timing for MBT conditions and by holding the speed at 1800 rpm and Brake Mean effective Pressure (BMEP) at 12 bar. The effect of dilution on CO*{sub 2}chemiluminescence intensities was studied, by varying the global equivalence ratio (0.6-1.0) and by varying the exhaust gas recirculation rate. It was attempted to relate the measured chemiluminescence intensities to thermodynamic metrics of importance to engine research -- in-cylinder bulk gas temperature and heat release rate (HRR) calculated from measured cylinder pressure signals. The peak of the measured CO*{sub 2} chemiluminescence intensities coincided with peak pressures within {+-}2 CAD for all test conditions. For each combustion cycle, the peaks of heat release rate, spectral intensity and temperature occurred in that sequence, well separated temporally. The peak heat release rates preceded the peak chemiluminescent emissions by 3.8-9.5 CAD, whereas the peak temperatures trailed by 5.8-15.6 CAD. Such a temporal separation precludes correlations on a crank-angle resolved basis. However, the peak cycle heat release rates and to a lesser extent the peak cycle temperatures correlated well with the chemiluminescent emission from CO*{sub 2}. Such observations point towards the potential use of flame chemiluminescence to monitor peak bulk gas temperatures as well as peak heat release rates in natural gas fired reciprocating engines.

A heavy-duty industrial gas turbine combustion system has been designed and laboratory tested for use with low heating value coal gas produced by an air-blown Lurgi coal gasifier. The design fuel has a nominal lower heating value of 4.21 MJ/Nm/sup 3/ (107 BTU/SCF). The combustor design utilizes high-swirl fuel and air injection to provide rapid fuel/air mixing and a stable flame front, and is physically interchangeable with the conventional fuel combustion system for the General Electric Model MS5001 gas turbine. Full-pressure, full-scale tests of the new combustion system have been conducted at the General Electric Gas Turbine Development Laboratory in Schenectady, New York, USA, for the Shanghai Power Plant Equipment Research Institute (SPPERI) of the Peoples Republic of China. Simulated clean low heating value coal gas fuel with a composition specified by SPPERI was used for these tests. Laboratory test reults are presented for important combustor operating parameters, including exhaust emissions, combustion efficiency, exhaust temperature profile, dynamic pressure, and metal temperature distribution.

Corrosion behavior of ferritic stainless steels was studied in artificial exhaust gas condensates containing corrosive ions such as Cl{sup {minus}} and SO{sub 3}{sup 2{minus}}. Continuous immersion tests in flasks and Dip and Dry tests by using the alternate corrosion tester with a heating system clarified the effects of chromium and molybdenum additions on the corrosion resistance of a ferritic stainless steel in the artificial exhaust gas condensates. Effects of surface oxidation on the corrosion behavior were investigated in a temperature range of 573K to 673K. Oxidation of 673K reduced the corrosion resistance of the ferritic stainless steels in the artificial environment of the automobile muffler. Particulate matter deposited on the muffler inner shell from the automobile exhaust gas was also examined. Deposited particulate matter increased the corrosion rate of the ferritic stainless steel. Finally, the authors also investigated the corrosion of the automobile mufflers made of Type 436L ferritic stainless steel with 18% chromium-1.2% molybdenum after 24 months, in Japan. The sets of results clarified that Type 436L ferritic stainless steel as the material for the automobile muffler exhibited acceptable corrosion resistance.

A new method of continuous measurement of formaldehyde has been developed with second order derivative spectrophotometry, in order to establish the measurement device of practical use for exhaust gas out of methanol fueled vehicles. In this device, a suppressing system of flow rate change due to pressure change of exhaust gas during a transient drive and a heating system to uniform temperature distribution of the cell are adopted. Detection limit, responsibility, effect of interference component and et al. are examined and evaluated. For application tests, the steady test and the modal test are carried out by using exhaust gas out of a methanol fueled vehicle (M85). Results obtained by the experimental studies are as follows. Minimum detection limit is 5 ppm. Responsibility is about 5 seconds at 5 l/min in measured flow rate. The measurement of formaldehyde is not interfered by SO{sub 2} or NO{sub 2} when 304.4 nm is used as the wave length for measurement. This method corresponds well with DNPH-GC method and so is highly reliable. 5 refs., 11 figs., 1 tab.

This paper introduces a summary of the gas cogeneration installation introduced to Hotel New Grand in Yokohama. The installation is a gas cogeneration system which has advantages in overall efficiency and in environmental preservation. This system is a steam recovering type. The engine cooling water temperature is raised to 120[degree]C, the calorific power of the cooling water is recovered as steam. Steam of 8 kg/cm[sup 2]G is further recovered from the waste gas to raise the efficiency. The gas engine generator generates power of 480 kW, which is linked to a utility power line. Cooling the engine interior using high-temperature water produces saturated steam of 1 kg/cm[sup 2]G in the air-water tank, which is utilized for preheating the hot water supply system. Waste heat from the exhaust gases is recovered in a steam boiler which generates saturated steam of 8 kg/cm[sup 2]G that is utilized for room warming and cooling. Recovery of the exhaust gases raising their temperature up to 150[degree]C, plus recovery of both saturated steams result in a steam recovery rate of 44.8% and an overall efficiency of 77%. 9 figs., 1 tab.

The $\\rho$ meson self-energy in nuclear matter from baryonic loops is analysed in the real time formulation of field theory at finite temperature and density. The discontinuities across the branch cuts of the self-energy function are evaluated for an exhaustive set of resonances in the loops considering the fully relativistic thermal baryon propagator including anti-baryons. Numerical calculations show a significant broadening of the $\\rho$ spectral function coming from the Landau cut. Adding the contribution from mesonic loops, the full spectral function of the $\\rho$ in a thermal gas of mesons, baryons and antibaryons in equilibrium is evaluated at various values of temperature and baryonic chemical potential.

This study represents effect to attain to the exhaust gas and the exhaust noise by the inner shapes of automobile muffler, and obtained optimization-data for the inner muffler shapes by the temperature variation of the exhaust gas in muffler. The results of noise show to decrease in order of model-1, 2 and 3 under that the engine speed is 3500 R.P.M and similar values beyond it. CO represented good the model-2 at low engine speed and model-1 at high engine speed. The model-3 was show to tiny variation difference by the variables. HC decrease mostly by increase of the engine speed and expressed low values the model-2 at 3,000 R.P.M and the model-1 at high speed. Wholly, the model-2 expressed stable results. The temperature distributions expressed high distributions by increase of the engine speed, and the model-3 was express most good among three models. (author). 11 refs., 8 figs., 1 tab.

The aim of this study was to design new catalytic systems for the selective catalytic reduction of NO{sub x} with increased activity and improved dynamic behavior, particularly in the lower temperature range. This included the optimization of the kinetics. The catalysts, developed in our laboratory, were scrutinized under conditions corresponding to real exhausts and the sensitivity of the activity and selectivity to the different components in the exhaust gas was determined. Additionally, the kinetic behavior of a commercial sample, used as a reference catalyst, was investigated in the low temperature range. The work can be subdivided in the following main topics: - setup of a fully computer controlled pilot plant for exhaust gas catalysts, - preparation of chromia on titania catalysts with an improved activity and selectivity, - experimental investigations and simulations of the intrinsic kinetics of a commercial catalyst, a vanadia-titania aerogel catalyst and a titania supported chromia catalyst, - investigations of the deactivation behavior and of the SO{sub 2} poisoning of titania supported chromia catalysts by kinetic measurements, X-ray photoelectron spectroscopy analysis and transmission FTIR spectroscopy. (author) figs., tabs., refs.

This conference day was organized by the `radiations` section of the French association of thermal engineers. This book of proceedings contains 8 papers entitled: `simultaneous temperature and NO concentration measurements in a hydrogen-air turbulent flame`; `application of iodine laser induced fluorescence to temperature, pressure and velocity measurements`; `Doppler phase measurement of refractive index and temperature`; `experimental and numerical study of temperature fields of particulates in plasma jets`; `measurement and determination of temperatures and concentrations of hot exhaust gases with FTIR emission spectroscopy`; `combustion control in gas turbines using CO{sub 2} emission spectroscopy`; `analysis of gases temperature fields and particulate jets. Application to hydrogen-air, kerosene stato-reactors and to solid propellant jets`; `restitution of temperature and species profiles in pre-mixing flames by inversion of transmission and IR emission data. (J.S.)

The removal of NOx by catalytic technology at low temperatures (100-300^oC) is significant for flue gas of industry and exhaust gas of diesel engine; however, to develop the low-temperature catalyst (LTC) for selective catalytic reduction of NOx with ammonia (NH3-SCR) is still a challenge especially at temperature below 200^oC. This study reviews two types of LTC, the metal oxide catalyst and metal exchanged zeolite catalyst. The performances of Mn-based metal oxide with and without supports have been attempted to correlate with preparation method, precursor, and various supports. The role of manganese oxides with different phases as the most effective low temperature active component and the limitation of stability in the presence of H2O and SO2 are discussed. Fe, Cu exchanged zeolites as...

This work has indicated with proper benchmarking, that a Low Pressure (LP) turbine can be monitored for performance in real time. The work demonstrates by superheat testing of the LP exhaust that common heat balance programs, with upgrading of extraction models, can with high accuracy predict the Used-Energy-End-Point and isentropic efficiency. This paper presents methods, data reduction techniques and recommended on-line models useful for low pressure (LP) turbine thermal performance monitoring. This work was conducted at the Redondo Generating Station, Unit 7, a gas-fired plant rated at 450 MWe. The objective of the testing was to benchmark a turbine cycle computer simulator when the LP was in a superheated exhaust condition. LP superheat was achieved by reducing circulatory water flow, thus raising condenser pressure, and dropping load such that the LP`s used-energy-end-point was driven to superheat. Such benchmarking was not intended to establish `correction factors` applicable at full load operation, but rather only to assure that analytical models could track LP performance throughout the load range. A method of plotting a family of curves which indicates all possible operational conditions was established. A quick look at this curve would indicate for any LP inlet condition and for any condenser pressure, the possibility of superheated exhaust and the degree of that superheat given measured temperatures. The usefulness of this curve was clearly demonstrated during the test. The paper also discusses methods used to measure exhaust temperature (within basket tips, etc.), isolation of feedwater heaters, and other methods. Results indicated outstanding agreement between measured LP generation and predicted, while superheated. Details in the data indicated differential velocity profiles across the rotor axis. In addition, results indicated that the vendor`s exhaust loss curve was not applicable at low loads. Discussion and recommendations are offered.

A co-rotor engine and valving system is described. By means of the valve system, gas under pressure is admitted to and exhausted from motor chambers defined between the rotor vanes in a controlled manner. The rotor members are caused to be rotated under power through the admission and exhausting of the gas. (UK)

A combined cycle power plant incorporating a coal gasifier as the energy source. The gases leaving the coal gasifier pass through a liquid couplant heat exchanger before being used to drive a gas turbine. The exhaust gases of the gas turbine are used to generate both high pressure and low pressure steam for driving a steam turbine, before being exhausted to the atmosphere.

To understand the conditions of exhaust gas treatment at the transition point between the Large Helical Device (LHD) vacuum pumping system and the exhaust gas tritium recovery system, the gas flow rate and hydrogen concentration were measured. Simultaneous measurement of the exhaust gas flow rate and hydrogen concentration was made possible by applying two types of hydrogen monitors: a thermal conductivity sensor and a combustible gas sensor. The obtained results have led to remodeling of the LHD vacuum pumping system and an optimised plan of operation for the tritium recovery system.   

Autothermal fuel reforming (ATR) consists of reacting a hydrocarbon fuel such as natural gas or diesel with steam to produce a hydrogen-rich {open_quotes}reformed{close_quotes} fuel. This work has been designed to investigate the fuel reformation and the product gas combustion under gas turbine conditions. The hydrogen-rich gas has a high flammability with a wide range of combustion stability. Being lighter and more reactive than methane, the hydrogen-rich gas mixes readily with air and can be burned at low fuel/air ratios producing inherently low emissions. The reformed fuel also has a low ignition temperature which makes low temperature catalytic combustion possible. ATR can be designed for use with a variety of alternative fuels including heavy crudes, biomass and coal-derived fuels. When the steam required for fuel reforming is raised by using energy from the gas turbine exhaust, cycle efficiency is improved because of the steam and fuel chemically recuperating. Reformation of natural gas or diesel fuels to a homogeneous hydrogen-rich fuel has been demonstrated. Performance tests on screening various reforming catalysts and operating conditions were conducted on a batch-tube reactor. Producing over 70 percent of hydrogen (on a dry basis) in the product stream was obtained using natural gas as a feedstock. Hydrogen concentration is seen to increase with temperature but less rapidly above 1300{degrees}F. The percent reforming increases as the steam to carbon ratio is increased. Two basic groups of reforming catalysts, nickel - and platinum-basis, have been tested for the reforming activity.

The invention deals with a turbocharger, in particular with an exhaust gas turbocharger for an internal combustion engine, provided with a turbine and exhaust gas channels. It is intended to improve the performance of the turbocharger with simple means. This problem has been resolved by an injector nozzle for accelerating the exhaust gases. The static pressure in the exhaust channel decreases, effected by the nozzle system. Thus the pressure difference between inlet and outlet of the turbine is increased which results in a higher performance. The injection nozzle is formed as a ring, enclosing the exhaust channel. By this arrangement it is possible to construct a small exhaust gas turbocharger with the same performance. The start and running behaviour could be improved.

This paper presents a numerical model of an exhaust heat recovery system for a high temperature polymer electrolyte membrane fuel cell (HTPEMFC) stack. The system is designed as thermoelectric generators (TEGs) sandwiched in the walls of a compact plate-fin heat exchanger. Its model is based on a finite-element approach. On each discretized segment, fluid properties, heat transfer process and TEG performance are locally calculated for higher model precision. To benefit both the system design and fabrication, the way to model TEG modules is herein reconsidered; a database of commercialized compact plate-fin heat exchangers is adopted. Then the model is validated against experimental data and the main variables are identified by means of a sensitivity analysis. Finally, the system configuration is optimized for recovering heat from the exhaust gas. The results exhibit the crucial importance of the model accuracy and the optimization on system configuration. Future studies will concentrate on heat exchanger structures.

For homogeneous charge compression ignition (HCCI) combustion, the auto-ignition process is very sensitive to in-cylinder conditions, including in-cylinder temperature, in-cylinder components and concentrations. Therefore, accurate control is required for reliable and efficient HCCI combustion. This paper outlines a simplified gasoline-fueled HCCI engine model implemented in Simulink environment. The model is able to run in real-time and with fixed simulation steps with the aim of cycle-to-cycle control and hardware-in-the-loop simulation. With the aim of controlling the desired amount of the trapped exhaust gas recirculation (EGR) from the previous cycle, the phase of the intake and exhaust valves and the respective profiles are designed to vary in this model. The model is able to anticip...

A simple model for spark-ignited engines is proposed in which the residual exhaust gases of a combustion event affect ignition of the subsequent charge. The model is an example of a one-dimensional, discrete, nonlinear mapping of an interval. Laminar flame correlations incorporated within models for ignition exhibit Arrhenius kinetics. Small variations of the ignition time with respect to the expansion cycle alter the work produced by each cycle, thereby altering the exhaust-gas temperature. It is shown that the mixing of hot residual gases with a fresh charge is a sufficient mechanism to produce an instability of the ignition process, resulting in oscillatory behavior. When this instability is compounded with the effects of mixture turbulence, one obtains a novel picture of the well-known phenomenon of "cyclic dispersion" exhibited by such engines. PMID:17819493

Karanja (Pongamia pinnata) oil, a non-edible high viscosity (27.84cSt at 40degreeC) straight vegetable oil, was blended with conventional diesel in various proportions to evaluate the performance and emission characteristics of a single cylinder direct injection constant speed diesel engine. Diesel and karanja oil fuel blends (5%, 10%, 15%, and 20%) were used to conduct short-term engine performance and emission tests at varying loads (0%, 20%, 40%, 60%, 80%, and 100%). Tests were carried out over the entire range of engine operation and engine performance parameters such as fuel consumption, thermal efficiency, exhaust gas temperature, and exhaust emissions (smoke, CO, CO2, HC, NOx, and O2) were recorded. The brake specific energy consumption (BSEC), brake thermal efficiency (BTE), and ex...

The exhaust products of a solid rocket motor using as propellant 14% binder, 16% aluminum, and 70% (wt) ammonium perchlorate consist of hydrogen chloride, water, alumina, and other compounds. The equilibrium and some frozen compositions of the chemical species upon interaction with the atmosphere were computed. The conditions under which hydrogen chloride interacts with the water vapor in humid air to form an aerosol containing hydrochloric acid were computed for various weight ratios of air/exhaust products. These computations were also performed for the case of a combined SRM and hydrogen-oxygen rocket engine. Regimes of temperature and relative humidity where this aerosol is expected were identified. Within these regimes, the concentration of HCL in the aerosol and weight fraction of aerosol to gas phase were plotted. Hydrochloric acid aerosol formation was found to be particularly likely in cool humid weather.

A compact solid-state CO sensor has been eagerly desired for detecting incomplete combustion of gas appliances, because continuous monitoring of CO in combustion exhausts can prevent a serious CO poisoning accident from occurring. The relevant sensor should be not only highly sensitive to CO but also selective to CO against various coexistent gases such as H{sub 2}, CH{sub 4}, C{sub 3}H{sub 6}, CO{sub 2}, NO and water vapor. In addition it should at the temperature of the exhausts (200-400 {degrees}C). In order to develop such a CO sensor, an extensive search was carried out for semiconducting oxides and modifiers. As a result, an In{sub 2}O{sub 3}-based sensor modified with Rb{sub 2}O was found to be sensitive and selective to CO at 300-400 {degrees}C, as described below.

An experiment was made to develop an exhaust/fume system for an underground parking lot. The system was capable of watering cooling/watering gas suction as needed and reduced fume temperature and prevent the fume fan from stopping on fire and exhausted air normally. In the experiment, watering was made to three steel meshes in the duct to cool fire/smoke. Water film due to watering was formed on the mesh but the water film was damaged when a certain wind velocity was exceeded. The air flow temperature in the duct decreased in the process where air flowed in the duct from the outer surface of duct to external air due to cooling. The cooling effect due to watering was clear and the air flow temperature inside duct was maintained to be 280{degree}C or less on fire. The cooling effect was improved due to increase in the amount of watering and the thinning of mesh. An experiment on the elimination of pollutants on daily exhaust was performed. The concentration of CO and CO2 was maintained to be constant regardless of watering. Watering was effective to the elimination of dust (elimination rate of 80%) and was effective to NOx and SO2 to some extent. 1 ref., 10 figs., 3 tabs.

In the conventional phosphoric acid fuel cell, the selective corrosion due to phosphoric acid takes place at the inlet of the air preheater, since the high temperature exhaust gas from the air electrode containing phosphoric acid is supplied to the air preheater. This invention solves the problem. Spray devices which spray water mist into the gases coming out of the air electrode and the fuel electrode of the phosphoric acid fuel cell. When the water mist is sprayed into the exhaust gas from the fuel cell, the gas temperature is so lowered that the phosphoric acid corrosion does not take place any more, and that the phosphoric acid vapor or the acid mist is absorbed in the residual spray water mist which does not vaporize to be discarded as the drainage from the system. So that the corrosion of equipment by phosphoric acid can be effectively prevented. In order to increase the gas liquid contact efficiency of the spray water, it is preferable to use the demister or buffer plate in the passage. 7 figs.

This report discusses the development of a E7G 12-liter, lean-burn natural gas engine--using stoichiometric combustion, cooled exhaust gas recirculation, and three-way catalyst technologies--for refuse haulers.

This invention is a process for detecting low levels of nitrogen oxides (NO.sub.x) in a flowing gas stream (typically an exhaust gas stream) and a catalytic NO.sub.x sensor which may be used in that process.

The TiAl intermetallic compound having excellent low density and high temperature strength is expected to be used for driving system valves or gas exhaust system parts of automobile engines. But, even though the TiAl compound has the high temperature strength for a structural compound, it does not have such good oxidation resistance at temperatures higher than 800degC in comparison with a heat resistance steel or Ni based super alloys. Therefore, the authors of the paper have made accumulated studies on surface treatment technologies aiming at improving the high temperature oxidation resistance of the TiAl and have developed two kinds of surface treatments (FB treatment; fluidized bed furnace method and SB treatment; shot blast method) by which the TiAl may obtain in a simple and cheaper way an oxidation resistance in excess of the Ni based super alloys. Each of the developed surface treatments endows the TiAl with repeated oxidation resistance at 950degC, in atmosphere or in exhaust gas. WO3-FB treatment can treat a mass of products in a very short time. As it is possible to carry out the WO3-SB treatment at room temperature, it can endow the product with the oxidation resistance after the last finishing process. 6 refs., 6 figs.

The generation of self gas flow in a model SF/sub 6/ gas circuit breaker without puffer action is observed by high speed photography, shadow photography using a Q-switch ruby laser and time- and space-resolved spectrography. The model breaker is specially designed for observation of gas flow in all the spaces from the cylinder to the exhaust space. The results of the observations are compared with a free burning arc and show that the self gas flow to the arc in the breaker reduces the diameter of the arc, and raises the temperature of the arc core. This model breaker interrupts the current of 3 kArms with a transient recovery voltage of 2 kV/..mu..sec, though the pressure rise of the cylinder is less than 0.3 x 10/sup 5/ Pa.

We present an Euler-Lagrange method for the simulation of wood gasification in a bubbling fluidized bed. The gas phase is modeled as a continuum using the 2D Navier-Stokes equations and the solid phase is modeled by a Discrete Element Method (DEM) using a soft-sphere approach for the particle collision dynamic. Turbulence is included via a Large-Eddy approach using the Smagorinsky sub-grid model. The model takes into account detailed gas phase chemistry, zero-dimensional modeling of the pyrolysis and gasification of each individual particle, particle shrinkage, and heat and mass transfer between the gas phase and the particulate phase. We investigate the influence of wood feeding rate and compare exhaust gas compositions and temperature results obtained with the model against experimental ...

The gas separation technology, generally, includes liquefaction separation (distillation), absorption, adsorption, and membrane separation. The gas separation method is determined due to the mixed gas properties, role of separation during the process, and specifications of products. This paper reviews the distillation process, absorption process, adsorption process, and membrane separation process. For the distillation process, a production process of nitrogen and oxygen by the low temperature processing is illustrated. Recently, nitrogen with a purity of 99.99% and oxygen with 99.95% can be obtained by the low temperature processing. For the gas absorption process, the soluble component in gas is dissolved in a liquid by contacting gas with the liquid. The gas absorption is applied to the purification of raw gases, and the recovery of effective components or removal of harmful components in the exhaust gases. Porous solids, such as activated carbon, permutite, alumina, and silica, are used for gas adsorbents. Industrial applications of adsorption operation are illustrated. Furthermore, industrial applications of membrane gas separation are also introduced. 12 refs., 1 fig., 9 figs.

Chinese translation of ITP fact sheet about installing Waste Heat Recovery Systems for Fuel-Fired Furnaces. For most fuel-fired heating equipment, a large amount of the heat supplied is wasted as exhaust or flue gases. In furnaces, air and fuel are mixed and burned to generate heat, some of which is transferred to the heating device and its load. When the heat transfer reaches its practical limit, the spent combustion gases are removed from the furnace via a flue or stack. At this point, these gases still hold considerable thermal energy. In many systems, this is the greatest single heat loss. The energy efficiency can often be increased by using waste heat gas recovery systems to capture and use some of the energy in the flue gas. For natural gas-based systems, the amount of heat contained in the flue gases as a percentage of the heat input in a heating system can be estimated by using Figure 1. Exhaust gas loss or waste heat depends on flue gas temperature and its mass flow, or in practical terms, excess air resulting from combustion air supply and air leakage into the furnace. The excess air can be estimated by measuring oxygen percentage in the flue gases.

Exhaust emissions were characterized from a bi-fueled vehicle operating on compressed natural gas and two gasolines over a heavy acceleration/high speed driving cycle and during cold temperature operation. The test fuels included compressed natural gas (CNG) meeting California Air Resources Board emissions certification specifications, industry average gasoline formulated to the specifications of Reference Fuel A (RF-A) used in the CRC/Auto Oil program, and Federal reformulated gasoline (RFG) purchased at a commercial service station in metropolitan Houston. Exhaust emissions were evaluated over the light-duty chassis dynamometer portion of the Federal Test Procedure at 75 deg F and at 20 deg F, and the REP05 - a hot, stabilized, high speed, high acceleration driving cycle developed by the EPA to be representative of non-FTP, in-use driving. In addition, CNG emissions were evaluated over the US06 driving cycle. Average regulated exhaust emissions (total hydrocarbons, methane, carbon monoxide, and oxides of nitrogen) were evaluated in a manner consistent with the Code of Federal Regulations.

Ammonium bisulfate (ABS) forms in coal-fired power plant exhaust systems when ammonia slip from the NOx control system reacts with the sulfur oxides and water in the flue gas. The critical temperature range for ABS formation occurs in the air preheater, where ABS is known to cause corrosion and pluggage that can require unplanned outages and expensive cleaning. To develop mitigation strategies for the deleterious effects of ABS in air preheaters, it is important to know its formation temperature and deposition process. This paper describes a bench-scale experimental simulation of a single-channel air preheater, with the appropriate temperature gradient, used in conjunction with simulated coal combustion flue gas, including sulfur oxides, ammonia, and water vapor, to investigate the formati...

A two-step approach to conserving energy in the textile industry by decreasing gas consumption in dryer operations involves 1) the automatic control of dryer dampers to minimize the flow of exhaust heat and 2) the recovery and use of the exhaust heat to preheat incoming air. These measures could reduce natural gas consumption by 45-65%. Decreasing the exhaust flow rates entails increasing the dryer humidity to a maximum level (about 0.1 lb water/lb dry air) and controlling it by the stack dampers. Three types of air-to-air heat exchangers appear suitable for preheating the dryer air by the sensible exhaust heat.

Replacing fossil fuels by renewable sources of energy is one approach to address the problem of global warming due to anthropogenic emissions of greenhouse gases. Wood combustion can help to replace fuel oil or gas. It is advisable, however, to use modern technology for combustion and exhaust gas after-treatment in order to achieve best efficiency and avoid air quality problems due to high emission levels often related to small scale wood combustion. In this study, simultaneous combustion particle deposition and heat recovery from the exhaust of two commercially available wood-fired appliances has been investigated. The experiments were performed with a miniature pipe bundle heat exchanger operating in the exhaust gas lines of a fully automated pellet burner or a closed fireplace. The system has been characterised for a wide range of aerosol inlet temperatures (135-295 deg. C) and flow velocities (0.13-1.0ms{sup -1}), and particle deposition efficiencies up to 95% have been achieved. Deposition was dominated by thermophoresis and diffusion and increased with the average temperature difference and retention time in the heat exchanger. The aerosols from the two different appliances exhibited different deposition characteristics, which can be attributed to enhanced deposition of the nucleation mode particles generated in the closed fire place. The measured deposition efficiencies can be described by simple linear parameterisations derived from laboratory studies. The results of this study demonstrate the feasibility of thermophoretic particle removal from biomass burning flue gas and support the development of modified heat exchanger systems with enhanced capability for simultaneous heat recovery and particle deposition.

The part-load performance of gas and steam turbine combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry on the gas turbine part-load performance. Subsequently, in another paper, the effects of variable geometry on the part-load performance for combined cycles used for ship propulsion will be presented. Moreover, this paper is aimed at developing methodologies and deriving models for part-load simulations suitable for energy system analysis of various components within gas turbines. Two different gas turbine configurations are studied, a two-shaft aero-derivative configuration and a single-shaft industrial configuration. When both gas turbine configurations are running in part-load using fuel flow control, the results indicate better part-load performance for the two-shaft gas turbine. Reducing the load this way is accompanied by a much larger decrease in exhaust gas temperature for the single-shaft gas turbine than for the two-shaft configuration. As used here, the results suggest that variable geometry generally deteriorates the gas turbine part-load performance.

A bench-scale biofilter was evaluated for removing ammonia (NH3) from poultry house exhaust. The biofilter system was equipped with a compost filter to remove NH3 and calcium oxide (CaO) filter to remove carbon dioxide (CO2). Removal of NH3 and CO2 from poultry house exhaust could allow treated air with residual heat to be recirculated back into the poultry house to conserve energy during winter months. Apart from its use as a plant nutrient, NH3 removal from poultry house exhaust could lessen the adverse environmental impacts of NH3 emissions. Ammonia and CO2 were measured daily with gas detector tubes while temperatures in the poultry pen and compost filter were monitored to evaluate the thermal impact of the biofilter on treated air. During the first 37 days of the 54-day study, exhaust air from 33 birds housed in a pen was treated in the biofilter; for the final 17 days, NH3-laden exhaust, obtained by applying urea to the empty pen was treated in the biofilter. The biofilter system provided near-complete attenuation of a maximum short-term NH3 concentration of 73 ppm. During the last 17 days, with a mean influent NH3 concentration of 26 ppm, the biofilter provided 97% attenuation. The CaO filter was effective in attenuating CO2. Compared with a biofilter sized only for NH3 removal, an oversized biofilter would be required to provide supplemental heat to the treated air through exothermic biochemical reactions in the compost. The biofilter could conserve energy in poultry production and capture NH3 for use as plant nutrient. Based on this study, a house for 27,000 broilers would require a compost filter with a volume of approximately 34 m3. PMID:12602826

The main objective of this work was to study the performance of a diesel engine with insulated combustion chamber surfaces. The piston of the test engine was insulated by incorporating an air-gap between the crown made of nimonic and the piston body. The cylinder liner was coated externally with partially stabilized zirconia (PSZ). The cylinder head and valves were insulated by coating them with a layer of PSZ. Due to this semi-adiabatic nature of the engine, the average gas and metal surface temperatures were higher. It was also studied whether these high temperatures allowed the use of fuels of low cetane number. Tests with adiabatic engine indicated higher levels of energy in the engine exhaust which could be utilized by employing exhaust heat recovery methods. The cycle average gas temperatures and metal surface temperatures increased substantially with insulation of the combustion chamber. This enabled the use of low cetane fuels in this engine. Lower volumetric efficiency and higher frictional losses were observed.

ZSM-5 zeolite was in-situ synthesized successfully on the surface of honeycomb cordierite substrate, certified by XRD and SEM techniques. Good thermal and hydrothermal stability of ZSM-5/cordierite could be obtained because of the in-situ synthesis method. Copper ion-exchanged ZSM-5/cordierite was studied as catalyst for selective catalytic reduction of nitrogen oxides. For practical reasons, the catalytic testing experiments were preformed on a real lean burn engine. Unburned hydrocarbons and carbon monoxide in the exhaust were directly used as reductants for NOx reduction. Cu-ZSM-5/cordierite exhibited high catalytic activity, and at 673 K the maximal NOx conversion to N2 could reach 50% at gas hourly space velocity (GHSV) of about 25 000 h(-1). Hydrocarbons and carbon monoxide in the exhaust could also be purified at the same time. As expected, Cu-ZSM-5/cordierite catalyst exhibited good duration and antipoison properties. When traces of lanthanum were introduced to Cu-ZSM-5/cordierite catalyst as a modifier, the activated temperature of the catalyst could be decreased and the temperature window with high NOx conversions broadened. Cu-ZSM-5/ cordierite and LaCu-ZSM-5/cordierite were thought as promising automobile exhaust catalysts under lean conditions. Copper is the main active component in the Cu-ZSM-5/ cordierite catalyst and Cu(II), which was found in the catalyst during the proceeding of reaction by XPS, is thought to be essential. On the basis of this, deNOx process over Cu-ZSM-5/cordierite is also discussed. PMID:15884384

The invention concerns a method and a device which generates a fuel metering signal M in a diesel engine based on parameters such as position of the accelerator, speed, lambda, exhaust gas temperature and torque. Depending on the accelerator position a fuel quantity request MW is set. This request and a second signal is transferred to a minimum selector whose output signal M will determine the quantity of metered fuel. The second signal comes from a pilot family of characteristics and depends on the speed. Under certain operational conditions the output signal of the pilot family of characteristics MW will be influenced by a regulator output signal MR.

An exhaust system that processes exhaust generated by an engine has a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates in the exhaust. An electrical heater is disposed upstream of the DPF and selectively heats the exhaust to initiate combustion of the particulates. Heat generated by combustion of particulates in the heater induces combustion of particulates within the DPF. A control module selectively enables current flow to the electrical heater for an initial period of a DPF regeneration cycle, and limits exhaust flow while the electrical heater is heating to a predetermined soot combustion temperature.

An improved waste oil heater is disclosed that includes a vaporizer pan having a mounting ring, a replaceable aluminum foil piece mounted on the ring to form the bottom of the pan and a member mounted on the ring to provide threads, a tool threadingly engageable with the threaded ring member for breaking the pan loose from the bottom wall of a burner pot and removing the ring with caked residue thereon for purposes of cleaning, the burner pot having a novel arrangement of apertures for flow of air into the pot, and solid state electronic control apparatus to control the feed of waste oil that automatically compensates for variations in viscosities and caloric values found in a variety of used oils and automatically discontinues the feed in the event the flame in the burner pot goes out. A thermocouple in the exhaust gas stream in the heater or in the stack senses the exhaust gas temperature and the control circuit operates the motor of the pump to feed oil to the pan at a fast or slow rate as determined by a room thermostat and the sensed stack gas temperature. The feeding of oil by the pump is controlled by the thermostat which alters the effect of the thermocouple by requiring a higher thermocouple voltage to produce slow feeding when the thermostat calls for more heat to be produced.

The Solid Waste Incineration Facility for Testing (SWIFT) has operated for 400 hours and burned 25,000 lb of waste. After the facility startup in October 1981, three week-long campaign runs were conducted. During these tests, the incinerator processed a wide variety of simulated (nonradioactive) waste at rates of 300 to 400 lb/h. The resulting ash reduced the storage volume of the waste by a factor of 20. The off-gas treatment successfully cooled the exhaust from 1000 to 180/sup 0/C and filtered particulates from the gas stream. Cleaned off-gas was released to the atmosphere at 100/sup 0/C. Monitoring of the exhaust gas determined that pollutant and particulate concentrations were below South Carolina and Federal limits. A few areas need improvement, such as more adequate ash removal, better temperature control, and reduced air in-leakage. Performance of the equipment and materials of concentration was very good with only minor exceptions. This report contains extensive information on incinerator operation and data from burning tests.

A combined-cycle power plant is described that uses (1) heat from a high-temperature nuclear reactor to meet base-load electrical demands and (2) heat from the same high-temperature reactor and burning natural gas, jet fuel, or hydrogen to meet peak-load electrical demands. For base-load electricity production, fresh air is compressed; then flows through a heat exchanger, where it is heated to between 700 and 900 C by heat provided by a high-temperature nuclear reactor via an intermediate heat-transport loop; and finally exits through a high-temperature gas turbine to produce electricity. The hot exhaust from the Brayton-cycle gas turbine is then fed to a heat recovery steam generator that provides steam to a steam turbine for added electrical power production. To meet peak electricity demand, the air is first compressed and then heated with the heat from a high-temperature reactor. Natural gas, jet fuel, or hydrogen is then injected into the hot air in a combustion chamber, combusts, and heats the air to 1300 C-the operating conditions for a standard natural-gas-fired combined-cycle plant. The hot gas then flows through a gas turbine and a heat recovery steam generator before being sent to the exhaust stack. The higher temperatures increase the plant efficiency and power output. If hydrogen is used, it can be produced at night using energy from the nuclear reactor and stored until needed. With hydrogen serving as the auxiliary fuel for peak power production, the electricity output to the electric grid can vary from zero (i.e., when hydrogen is being produced) to the maximum peak power while the nuclear reactor operates at constant load. Because nuclear heat raises air temperatures above the auto-ignition temperatures of the various fuels and powers the air compressor, the power output can be varied rapidly (compared with the capabilities of fossil-fired turbines) to meet spinning reserve requirements and stabilize the electric grid. This combined cycle uses the unique characteristics of high-temperature reactors (T>700 C) to produce electricity for premium electric markets whose demands can not be met by other types of nuclear reactors. It may also make the use of nuclear reactors economically feasible in smaller electrical grids, such as those found in many developing countries. The ability to rapidly vary power output can be used to stabilize electric grid performance-a particularly important need in small electrical grids.

There are two nitrogen/argon exhaust headers in the D0 cryogenic piping system, one for the liquid argon dewar and another for the three argon calorimeters. These headers serve two functions, venting both nitrogen exhaust from the cooling loops and cold argon gas should any argon vessel blow a relief. These headers are vacuum jacketed until they exit the building. At that point, uninsulated exhaust stacks direct the flow into the atmosphere. This note deals with the these stacks.

In this paper, the solid oxide fuel cell/gas turbine (SOFC/GT) cycle is integrated with coal gasification and chemical looping hydrogen generation (CLHG) for electric power production with CO2 capture. The CLHG-SOFC/GT plant is configurated and the schematic process is modeled using Aspen Plus software. Syngas, produced by coal gasification, is converted to hydrogen with CO2 separation through a three-reactors CLHG process. Hydrogen is then fueled to SOFC for power generation. The unreacted hydrogen from SOFC burns in a combustor and drives gas turbine. The heat of the gas turbine exhaust stream is recovered in HRSG for steam bottoming cycle. At a system pressure of 20 bar and a cell temperature of 900 degreeC, the CLHG-SOFC/GT plant has a net power efficiency of 43.53% with no CO2 emissio...

In order to reduce CO{sub 2} emission to prevent global warming, the most promising way for electric generation in the Northeast Asia is to introduce cogeneration and {open_quotes}repowering{close_quotes} technologies based on high temperature gas turbines fueled by natural gas. Especially the old type coal burning boiler-steam turbine plants should be retrofit by introducing gas turbines to become highly efficient combined cycle. Same technologies should be applied to the old garbage incineration plants and/or even to the nuclear power plants. The exhaust heat or steam should become much increased and it should be utilized as the process heat for industries or heat supply as the distinct heating or cooling for residential area. This paper introduces a brief survey of these new technologies.

The invention refers to a turbo-supercharger for internal combustion engines, particularly a multiple exhaust gas turbo-supercharger for vehicle engines, with a radial turbine wheel and exhaust gas inlets surrounding the turbine wheel in the turbine housing spirally. Further, a control device is provided to ensure an optimum turbine loading for different conditions of the engine. When the engine load is high, part of the exhaust gas is taken past in the bypass on the turbine wheel. The purpose of the invention is to create such an exhaust gas turbo-supercharger so that correct regulation of the charging system is guaranteed in all speed ranges. The invention solves this problem by providing a bypass duct concentrically surrounding the spiral exhaust gas inlet in the turbine housing, and fitting a valve control at the end of the bypass, which is actuated by the amount of the charging pressure or the amount of the exhaust gas pressure. This makes it possible to take the quantity of exhaust gas past in the bypass without affecting the 'floods' loading the turbine, by simple means.

The spray development, combustion and emissions in a 1.9L optical, four-cylinder, direct-injection diesel engine were investigated by means of pressure analysis, high-speed cinematography, the two-color method and exhaust gas analysis for various levels of exhaust gas recirculation (EGR), three EGR temperatures (uncontrolled, hot and cold) and three fuels (diesel, n-heptane and a two-component fuel 7D3N). Engine operating conditions included 1,000 rpm/idle and 2,000 rpm/2bar with EGR-rates ranging from 0 to 70%. Independent of rate, EGR was found to have a very small effect on spray angle and spray tip penetration but the auto-ignition sites seemed to increase in size and number at higher EGR-rates with associated reduction in the flame luminosity and flame temperature, by, say, 100K at 50% EGR. The emission tests confirmed that for different intake temperatures and three fuels, increasing the EGR-rate leads to reduced NO{sub x} and O{sub 2} levels but increased soot, CO, CO{sub 2}, and HC concentrations. Cold EGR resulted in lower NO{sub x} emissions at EGR-rates below 30% but at higher rates hot EGR seems to offer marginal improvements relative to cold EGR and significant NO{sub x} reduction compared to the uncontrolled EGR case.

As domestic gas was detoxified in the United States, the rate of suicide by domestic gas decreased. During this time period (1950-60), there was a parallel increase in the per capita ownership of cars and an accompanying increase in the rate of suicide by motor vehicle exhaust. However, displacement of suicide method from domestic gas to car exhaust occurred only for males and not for females.

A computer program to calculate the temperature profile of a flame or hot gas was presented in detail. Emphasis was on profiles found in jet engine or rocket engine exhaust streams containing H2O or CO2 radiating gases. The temperature profile was assumed axisymmetric with an assumed functional form controlled by two variable parameters. The parameters were calculated using measurements of gas radiation at two wavelengths in the infrared. The program also gave some information on the pressure profile. A method of selection of wavelengths was given that is likely to lead to an accurate determination of the parameters. The program is written in FORTRAN IV language and runs in less than 60 seconds on a Univac 1100 computer.

Blowby and gas flow through the cylinder-piston-ring crevices are phenomena that affect the engine performance and exhaust emissions. Also these phenomena influence the cylinder pressure and temperature and the charge amount during a cycle. The study and validation of a sub-model for these phenomena in the absence of engine combustion deducts all effects arisen from the combustion event. During the current study, blowby sub-model and gas flow through crevices under motoring conditions has been noticed using a volume-orifice theory and the experimental results measured from a research engine. Blowby geometric parameters, consisting of a few critical cross-section areas (orifice areas) and volumes (top land and inter-ring crevice volumes), were measured in ambient temperature and corrected f...

The effect of direct water injection on the exhaust gas emissions of a turbojet combustor burning natural gas fuel was investigated. The results are compared with the results from similar tests using ASTM Jet-A fuel. Increasing water injection decreased the emissions of oxides of nitrogen (NOX) and increased the emissions of carbon monoxide and unburned hydrocarbons. The greatest percentage decrease in NOX with increasing water injection was at the lowest inlet-air temperature tested. The effect of increasing inlet-air temperature was to decrease the effect of the water injection. The reduction in NOX due to water injection was almost identical to the results obtained with Jet-A fuel. However, the emission indices of unburned hydrocarbons, carbon monoxide, and percentage nitric oxide in NOX were not.

New burner systems with lower exhaust gas temperatures resulted in increased reconstruction of chimneys within the last years. The traditional materials for reconstruction such as leight weight concrete shells or flexible special steel pipes proved to be insufficient. Nowadays rigid special steel pipes with and without heat insulating shell as well as fire-clay pipes, which are applied with acid-resisting cement and backfilled with insulating layer. Recusist special glass is regarded as a relatively new, efficient reconstructional material. In addition to their corrosion resistance, Recusist is gas- and condensate tight resistant to temperature change, favorable with regard to flow, non-porous (and thus, easily to clean) as well as not harmful to the environment. (orig.).

Development has been completed of a ceramic recuperator and its companion high-temperature preheated combustion air burner. The system is designed to operate in a variety of industrial flue gas streams with exhaust temperatures up to 2500/sup 0/F. The ceramic recuperator provides combustion air preheated up to 2000/sup 0/F to the high-temperature burner. Development of low-pressure seals to join the ceramic recuperator components was performed as an integral part of the program. While operating at high temperatures, the recuperator requires seals effective in minimixing both leakage and stress concentrations in the joints between ceramic components. Seal design, composition, leakage performance, and seal characterization were evaluated for cement, glass, and fiber packing seals. Laboratory studies have demonstrated that effective, low-leakage seals were developed and incorporated into the HTBDR industrial design.

To protect the global environment by using energy more efficiently, NTT is developing a phosphoric acid fuel cell (PAFC) energy system for telecommunication cogeneration systems. Fuel cells are used to provide electrical power to telecommunication equipment and the heat energy is used by absorption refrigerators to cool the telecommunication rooms throughout the year. We have recently developed a highly efficient system for recovering heat and water from the exhaust gases of a 200-kW (rated power) fuel cell. It is composed of a shell-and-tube type heat exchanger to recover high-temperature heat and a direct-contact cooler to recover the water efficiently and simply. The reformer and cathode exhaust gases from the fuel cell are first supplied to the heat exchanger and then to the cooler. The high-temperature (85-60 C) heat can be recovered, and the total efficiency including the heat recovered from the fuel-cell stack coolant can be improved by supplying the recovered heat to the dual-heat-input absorption refrigerator. The water needed for operating the fuel cell is also recovered from the exhaust gases. We are currently applying this heat and water recovery system to the PC25C-type fuel cell. Maximum total efficiency including electrical power efficiency is estimated to be 78% at the rated power of 200 kW: composed of 17% heat recovery for the fuel-cell stack coolant, 21% from the exhaust gas by improving the heat exchanger, and 40% from electrical conversion. Next, we plan to evaluate the usefulness of this heat recovery system for cooling telecommunication equipment. (orig.)

Visible smoke of exhaust gas from iron ore sintering plants spoil the scenery around the works. In this paper, the mechanism of formation of visible smoke is discussed by detailed analysis of the exhaust gas components and dust in the Oita No. 1 sintering plant. The main substance of visible smoke was mist condensing in the air during the cooling of exhaust gas that contained 0.1 ppm of sulfuric acid (SO3). Sulfuric acid is considered to raise the dew point and so facilitate mist condensation, and to lower the vaporization of visible mist containing sulfuric acid solution. Dust in the exhaust gas is also considered to act as nucleation sites for mist condensation. This proposed mechanism was confirmed by the test remixing SOx-rich gas with desulfurization gas in the Nagoya No. 3 sintering plant. Long trails of visible smoke were observed by remixing SOx-rich gas with exhaust gas. In conclusion, in order to make exhaust gas invisible, it is not sufficient to enhance the dust collecting system: desulfurization equipment in the sintering plant is necessary.   

Studies on cleaning the exhaust gas of chip driers were carried out employing water and aqueous soidum hydroxide as scrubbing solutions. In addition exhaust gas cleaning through indirect cooling was investigated. The decrease of the total carbon content in the exhaust gas through water-scrubbing was 55%, through aqueous sodium hydroxide 70% and through indirect cooling 18%. Investigations on the change in concentration of the terpenes ..cap alpha..-pinene, ..beta..-pinene, myrcene, ..delta../sup 3/-carene and camphene showed that these compounds followed closely the reduction efficiency measured for the total carbon content.

A system and method for efficiently generating power using a gas turbine, a steam generating system (20, 22, 78) and a reformer. The gas turbine receives a reformed fuel stream (74) and an air stream and produces shaft power and exhaust. Some of the thermal energy from the turbine exhaust is received by the reformer (18). The turbine exhaust is then directed to the steam generator system that recovers thermal energy from it and also produces a steam flow from a water stream. The steam flow and a fuel stream are directed to the reformer that reforms the fuel stream and produces the reformed fuel stream used in the gas turbine.

This patent describes a combined cycle power plant. It comprises a steam turbine including an inlet portion for receiving motive steam and an exhaust portion for exhausting the motive steam that is spent by the steam turbine; a condenser connected to the exhaust portion of the steam turbine for receiving the spent motive steam and for condensing the spent motive steam to a supply of condensate; a gas turbine including an exhaust portion for exhausting waste heat that is produced by the gas turbine in the form of exhaust gases; a heat recovery steam generator connected between the exhaust portion of the gas turbine and the steam turbine, for receiving the waste heat exhausted by the gas turbine, for generating the motive steam from a supply of feedwater heated by the waste heat, and for supplying the motive steam to the steam turbine; a deaerator connected to the condenser for receiving the supply of condensate and for deaerating the condensate to provide the supply of feedwater to the heat recovery steam generator; and a heat exchanger.