Injecting system

For optimum combustion, the fuel should vaporize rapidly and mix intimately with the air. Even though the design of the injection system and combustion chamber play a very important role, properties such as volatility, surface tension, and fuel viscosity also affect the quality of atomization and penetration of the fuel. These considerations justify setting specifications for the density (between 0.775 and 0.840 kg/1), the distillation curve (greater than 10% distilled at 204°C, end point less than 288°C) and the kinematic viscosity (less than 8 mm /s at -20°C). 

Other heavy fuel contaminants are metals (vanadium, nickel, sodium) coming from the crude oil itself or metallic salts (aluminum silicates) coming from catalysts in conversion steps. The aluminum silicates should not exceed 300 ppm (30 ppm of aluminum), for these materials exert a strong abrasive action on the engine cylinders and injection systems. They can however be eliminated partially by centrifuging and filtration. 

B. M. Bertilsson, "Regulated and Unregulated Emissions from an Alcohol-Pueled Diesel Engine with Two Separate Euel Injection Systems," 5th Int. Symp. on AlcoholEuel Technology (Auckland, New Zealand, May 13—18, 1982) Vol. 3. 

Problems associated with the implementation of a direct cylinder injection system are (/) the injection of the hydrogen gas must be carefully... 

Example 4. A particular microprocessor (MPU) is assigned for a fuel-injection system. The failure rate must be estimated, and 100 MPUs are tested. The test is terrninated when the fifth failure occurs. Failed items are not replaced. This type of testing, where n is the number placed on test and ris the number of failures specified, is termed a Type II censored life test. 

Since these MPUs are used to control fuel-injection systems, it might be interesting to know the 24,000-km rehabiUty (the warranty period). Assuming an average speed of 80 km/h, 300 h of use are obtained. The rehabiUty would be estimated as... 

In most cases, FBCs employ some type of air injection system in the floor of the furnace both to impart turbulence into the burning fuel bed and supply combustion air. Secondary and tertiary air ports may be located above the burning fuel bed. 

SPME has been utilized for deterrnination of pollutants in aqueous solution by the adsorption of analyte onto stationary-phase coated fused-siUca fibers, followed by thermal desorption in the injection system of a capillary gas chromatograph (34). EuU automation can be achieved using an autosampler. Eiber coated with 7- and 100-p.m film thickness and a nitrogen—phosphoms flame thermionic detector were used to evaluate the adsorption and desorption of four j -triazines. The gc peaks resulting from desorption of fibers were shown to be comparable to those obtained using manual injection. 

Enzyme immunosensors are used in flow injection systems and Hquid chromatography to provide automated on-line analyses (71—73). These systems are capable of continuously executing the steps involved in the immunoassays, including the binding reactions, washing, and the enzyme reaction, in about 10 minutes. 

The performance of the catalytic converter is affected by the conditions of air/fuel control provided by the fuel metering system. A slowly responding fuel metering system can dramatically decrease the conversion efficiency of the converter compared to a fast response multipoint fuel injection system. 

M. Nuti, M Variable Timing Electronically Controlled High Pressure Injection System for 2S S.I Engines, SAE 900799, Society of Automotive Engineers, Warrendale, Pa., 1990. 

A flow-injection system with electrochemical hydride generation and atomic absorption detection for the determination of arsenic is described. This technique has been developed in order to avoid the use sodium tetrahydroborate, which is capable of introducing contamination. The sodium tetrahydroborate (NaBH ) - acid reduction technique has been widely used for hydride generation (HG) in atomic spectrometric analyses. However, this technique has certain disadvantages. The NaBH is capable of introducing contamination, is expensive and the aqueous solution is unstable and has to be prepared freshly each working day. In addition, the process is sensitive to interferences from coexisting ions. 

Water injection, or steam injection systems, are being used extensively to augment power. Corrosion problems in the compressor diffuser and combustor have not been found to be major problems. The increase in work and efficiency with a reduction in NO makes the process very attractive. Split-shaft cycles are attractive for use in variable-speed mechanical drives. The off-design characteristics of such an engine are high efficiency and high torque at low speeds. 

Humidified Compressed Air Injeetion System are about the same. This is due to the faet that though the initial eost to install the Compressed Air System, for a turbine of about 100 MW, is about 3.7 million as compared to about 1.7 million for a steam injection system, the power generated by the Heated and Humidified Compressed Air Injection System is much higher. 

The rate of return on the steam injection system is higher than the Compressed Air Injection System. This is due to the fact that though the efficiency of the steam injection system and the compressed air injection system is about the same, however, the initial cost of the steam injected system being over 50% lower than the compressed air injection system accounts for the difference. 

Main fuel injector. This unit is designed to deliver a fuel-air mixture to the catalyst that is uniform in composition, temperature, and velocity. A multi-venturi tube (MVT) fuel injection system was developed by GE specifically for this purpose. It consists of 93 individual venturi tubes arrayed across the flow path, with four fuel injection orifices at the throat of each venturi. 

Isolation and safety Sample and check transformer oil Water Treating Load filter beds Load ion exchanger Make up injection systems Cooling Water... 

Applicability Limitation This technology is used primarily to treat solids, sludges and contaminated soils, but liquid or gaseous injection systems are available. 

Elapsed Time in Thousands of Reactor Years Fig. 2.7-1 ERMA simulation of a low pressure coolant injection system. The absence of oscillations in the convergence is evidence of voter statistics Reprinted with permission of EPRI. USA... 

An example of a multipurpose system is a reactor s low pressure coolant injection system which uses one out of four (1/4) pumps for a small LOCA, and three-out-of-four pumps for a large LOCA (3/4). The top event for the small LOCA might be "none of four LPCI pump u1... 

Figure 3.4.4-6 presents a flow diagram of a simplified emergency cooling injection system. It is activated by a safety injection signal (SIS) which... 

Construct RBD of the simple injection system shown in Figure 3.4.4-6. 

In some BWR transient scenarios, the high pressure injection systems are postulated to fail. To make use of the low pressure injection system, it is necessary to depressurize the reactor coolant system, a function performed by the automatic depressurization system (ADS). In the scenario considered, ADS actuation is manual because the signals for automatic initiation of the system are not present. 

Initially, assume that failure occurs if the water level drops below the top of the core. This occurs 30 minutes after the initiating c ent, if at least one of the injection systems did not operate successfully. 

Remove core decay heat High pressure injection system Low pressure injection system High pressure recirculation system Core flood tanks Auxiliary feedwater system Power conversion system Remove core decay heat Auxiliary feedwal stem Power conversion m High pressure inj( i system pow. peiuicd relief valves... 

Prevent containment overpressure Reactor building spray injection system Reactor building spray recirculation system Reactor building fan coolers Ice condensers Prevent containment overpressure Containment spray injection system, containment spray recirculation system containment fan c ng system, ice conde... 

The safety improvements use redundancy and diversity to prevent and mitigate lents. The safety injection system (SIS) and emergency feedwater system (EFWS) are dedicated four train systems. Containment spray and safety injection pumps take water from the in-containment water storage tank (IRWST), thus, eliminating the need to switch from an external source and provide a. semi-closed system with continuous recirculation. Emergency core coolant flows direc nto the... 

These plants are designed with two independent high-pressure injection systems, namely reactor cooling sure coolant injection (HPCl). The associated pumps are each potiered fay turbine. also have a multi-loop core spray system and a multi-mode residual heat re sy.stem that can be aligned for low-pressure coolant injection, shutdown cooling, suppre.ssion pc containment spray functions. 

BWRs have more injection systems than PWRs and can depressurize more easily using low-pressure injection (LPI) systems which reduces the BWR LOCA vulnerability. Figure 11.1-1 shows some BWR CDFs are higher than some PWR CDFs The variation in the CDFs is driven primarily by a combination of the following factors ... 

A, . iil.ihility of firewater as a diverse injection system for BWRs... 

HWR v.trijbilny inosily driven by modeling of human errors and availability of alternative boron injection system... 

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