Influence of sludge cake concentration on the operating variables in incineration by different types of furnaces

1998 ◽  
Vol 38 (2) ◽  
pp. 71-78
Author(s):  
Giuseppe Mininni ◽  
Vincenzo Lotito ◽  
Roberto Passino ◽  
Ludovico Spinosa
Keyword(s):  
Fuel Consumption ◽  
Rotary Kiln ◽  
Flue Gas ◽  
Gas Production ◽  
Exhaust Gas ◽  
Operating Variables ◽  
Optimal Value ◽  
Different Types ◽  
Afterburning Chamber ◽  
Sludge Cake

The influence of cake concentration on fuel consumption, air requirement and flue gas production in incineration of sewage sludge is discussed. Fluidized bed (FBF), multiple hearth (MHF) and rotary kiln (RKF) furnaces are considered as alternatives together with the optional use of an afterburning chamber where exhaust gases are taken at 950°C for 2 s with an oxygen concentration of 6% by volume. It clearly appears that, if an afterburning chamber is used, and total minimum fuel consumption can be achieved at an optimal value of cake concentration (45.9% for FBF and 32.5% for MHF) when autogenous conditions are reached in the furnace and air addition is no longer needed in the afterburning chamber. At higher concentrations, abundant exhaust gas productions, due to the dilution air needed in the furnace, can considerably increase fuel consumption in the afterburning chamber, especially in MHF operation. In the rotary kiln furnace, fuel requirement decreases over the whole range of cake concentration as no conditions for autogenous combustion in the furnace can be achieved.

The Investigation on Application of Oxygen-Enriched Combustion in Cement Rotary Kiln

2013 ◽  
Vol 291-294 ◽  
pp. 804-808
Author(s):  
Xiao Rong Shen ◽  
Shan Qing ◽  
Xiao Jun Shi ◽  
Yi Xiao ◽  
Zhi Fang Yang
Keyword(s):  
Fuel Consumption ◽  
Rotary Kiln ◽  
Flue Gas ◽  
Thermal Efficiency ◽  
Flame Temperature ◽  
Exhaust Gas ◽  
Environmental Benefit ◽  
Gas Loss ◽  
The Cost ◽  
Products Of Incomplete Combustion

The investigation on application of oxygen-enriched combustion in cement rotary kiln shows that flame temperature in rotary kiln can be increased, which improves the utilization of coal and thermal efficiency of rotary kiln. And the fuel consumption and the cost of production can be reduced. In this situation, the objective of increasing production, improving quality and saving energy can be achieved. In the meanwhile, the requirement of air can be reduced in oxygen-enriched combustion. Thus the generation of flue gas and the products of incomplete combustion, which usually are CO, can be reduced. And then the exhaust gas loss and the generation and emission of CO2 and NOx can be accordingly reduced, which enhances to achieve the objective of reduction of pollutants and promote the environmental benefit greatly.

Employing Inverted Brayton Cycle to Solve Stack Temperature Problems After Water Recovery From HAT Cycle Exhaust Gas

2008 ◽  
Author(s):  
Kuifang Wan ◽  
Yunhan Xiao ◽  
Shijie Zhang
Keyword(s):  
Flue Gas ◽  
Ambient Pressure ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Exhaust Gas ◽  
Water Recovery ◽  
Electrical Efficiency ◽  
Exhaust Heat ◽  
Induced Draft Fan

By adding an induced draft fan or exhaust compressor between flue gas condenser and stack to make the turbine expand to a pressure much lower than ambient pressure, this paper actually employed inverted Brayton cycle to solve stack temperature problems after water recovery from Humid Air Turbine (HAT) cycle exhaust gas and compare the effect of different discharging methods on the system’s performance. Comparing with the methods of gas discharged directly or recuperated, this scenario can obtain the highest electrical efficiency under certain pressure ratio and turbine inlet temperature. Due to the introduction of induced draft fan, in spite of one intercooler, there are twice intercoolings during the whole compression since the flue gas condenser is equivalent to an intercooler but without additional pressure loss. So the compression work decreases. In addition, the working pressure of humidifier and its outlet water temperature are lowered for certain total pressure ratio to recover more exhaust heat. These enhance the electrical efficiency altogether. Calculation results show that the electrical efficiency is about 49% when the pressure ratio of the induced draft fan is 1.3∼1.5 and 1.5 percentage points higher than that of HAT with exhaust gas recuperated. The specific works among different discharging methods are very closely. However, water recovery is some extent difficult for HAT employing inverted Brayton cycle.

Automated Design of a Turbocharged, Fueled, Four-Stroke Engine for Minimum Fuel Consumption

1988 ◽  
Author(s):  
J. K. Woodard ◽  
G. E. Johnson ◽  
R. L. Lott
Keyword(s):  
Fuel Consumption ◽  
Fluid Model ◽  
Programming Algorithm ◽  
Intake Manifold ◽  
Optimization Strategy ◽  
Simulation Code ◽  
Operating Variables ◽  
Chamber Volume ◽  
Starting Point ◽  
Stroke Engine

Abstract The design of a turbocharged, gasoline fueled, four-stroke engine is considered with the goal of selecting design and operating variables to minimize fuel consumption. The development of the engine simulation code and the effect of model assumptions on the results are presented. The optimization includes constraints on detonation, exhaust emissions, and torque. Variables are bounded to assure the validity of the simulation. A number of observations about the interaction between the thermo-fluid model and the nonlinear programming algorithm are made and general strategies to enhance the optimization under such circumstances are discussed. The method is illustrated by exploring the design of a turbocharged Buick V-6 engine on an IBM PC/AT personal computer. Stock design variables, and operating variables that provided a design away from the constraints imposed by torque, emission, and detonation were chosen as the starting point for the optimization. Application of the optimization strategy resulted in an 18 percent reduction in predicted fuel consumption at 50 miles per hour. Significant specific recommendations included a reduction in combustion chamber volume, an increase in intake manifold pressure, an increase in intake duration, a decrease in exhaust duration, and relatively small changes in valve geometry. The paper clearly demonstrates that it is feasible to do relatively sophisticated engineering design and optimization on personal computers, and it sets the stage for further work in this area.

Sliding behavior of silica ball-shale rock contact under polyacrylamide aqueous solutions

2021 ◽  
pp. 1-25
Author(s):  
Huijie Zhang ◽  
Shuhai Liu
Keyword(s):  
Adverse Effect ◽  
Shale Gas ◽  
Normal Load ◽  
Gas Production ◽  
Wear Depth ◽  
Brine Solution ◽  
Shale Rock ◽  
Different Types ◽  
The Coefficient Of Friction ◽  
Specific Speed

Abstract The tribological properties of proppant particle sliding on shale rock determine the shale gas production. This work focuses on investigating the impacts of sliding speed on the coefficient of friction (COF) and wear of the silica ball-shale rock contact, which was lubricated by water or different types of polyacrylamide (PAM) aqueous or brine solution. The experimental results show that both boundary and mixed lubrication occur under specific speed and normal load. COF and wear depth of shale rock under water are higher than those under PAM solution due to superior lubrication of PAM. COF of shale rock under PAM brine solution increases and the wear of the rock is more serious, attributed to the corrosion of shale rock and adverse effect on lubrication of PAM by brine.

scholarly journals Ensuring Requirements for Emissions of Harmful Substances of Diesel Engines

2020 ◽  
Vol 19 (4) ◽  
pp. 305-310
Author(s):  
G. M. Kuharonak ◽  
D. V. Kapskiy ◽  
V. I. Berezun
Keyword(s):  
Diesel Engine ◽  
Nitrogen Oxides ◽  
Fuel Consumption ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Average Temperature ◽  
Dispersed Particles ◽  
Harmful Substances ◽  
Gas Recirculation ◽  
Emissions Of Harmful Substances

The purpose of this work is to consider the requirements for emissions of harmful substances of diesel engines by selecting design and adjustment parameters that determine the organization of the workflow, and the exhaust gas cleaning system, taking into account the reduction of fuel consumption. Design elements and geometric characteristics of structures for a turbocharged diesel engine of Д-245 series produced by JSC HMC Minsk Motor Plant (4ЧН11/12.5) with a capacity of 90 kW equipped with an electronically controlled battery fuel injection have been developed: exhaust gas recirculation along the high pressure circuit, shape and dimensions of the combustion chamber, the number and angular arrangement of the nozzle openings in a nozzle atomizer, and inlet channels of the cylinder head. Methods for organizing a workflow are proposed that take into account the shape of the indicator diagrams and affect the emissions of nitrogen oxides and dispersed particles differently. Their implementation allows us to determine the boundary ranges of changes in the control parameters of the fuel supply and exhaust gas recirculation systems when determining the area of minimizing the specific effective fuel consumption and the range of studies for the environmental performance of a diesel engine. The paper presents results of the study on the ways to meet  the requirements for emissions of harmful substances, obtained by considering options for the organization of working processes, taking into account the reduction in specific effective fuel consumption, changes in the average temperature of the exhaust gases and diesel equipment. To evaluate these methods, the following indicators have been identified: changes in specific fuel consumption and average temperature of the toxicity cycle relative to the base cycle, the necessary degree of conversion of the purification system for dispersed particles and NOx. Recommendations are given on choosing a diesel engine to meet Stage 4 emission standards for nitrogen oxides and dispersed particles.

scholarly journals Improvement of Alstom's Limestone-Based Chemical Looping Combustion Process for Higher Purity Flue Gas Production

2017 ◽  
Author(s):  
Timothy J. Braun ◽  
David G. Sloan ◽  
David G. Turek ◽  
Steve A. Unker ◽  
Frederic Vitse
Keyword(s):  
Flue Gas ◽  
Combustion Process ◽  
Gas Production ◽  
Chemical Looping Combustion ◽  
Chemical Looping

Different Configurations of Exhaust Gas Heat Recovery in Internal Combustion Engine: Evaluation on Different Driving Cycles Using Numerical Simulations

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Hanna Sara ◽  
David Chalet ◽  
Mickaël Cormerais
Keyword(s):  
Numerical Simulations ◽  
Fuel Consumption ◽  
Heat Recovery ◽  
Combustion Engine ◽  
Management Strategies ◽  
Driving Cycle ◽  
Maximum Temperature ◽  
Exhaust Gas ◽  
Direct Heating ◽  
Driving Cycles

Exhaust gas heat recovery is one of the interesting thermal management strategies that aim to improve the cold start of the engine and thus reduce its fuel consumption. In this work, an overview of the heat exchanger used as well as the experimental setup and the different tests will be presented first. Then numerical simulations were run to assess and valorize the exhaust gas heat recovery strategy. The application was divided into three parts: an indirect heating of the oil with the coolant as a medium fluid, a direct heating of the oil, and direct heating of the oil and the coolant. Different ideas were tested over five different driving cycles: New European driving cycle (NEDC), worldwide harmonized light duty driving test cycle (WLTC), common Artemis driving cycle (CADC) (urban and highway), and one in-house developed cycle. The simulations were performed over two ambient temperatures. Different configurations were proposed to control the engine's lubricant maximum temperature. Results concerning the temperature profiles as well as the assessment of fuel consumption were stated for each case.

A comparison of different types ot apparatus used for measuring gas production in vitro

1997 ◽  
Vol 1997 ◽  
pp. 193-193
Author(s):  
C. Rymer ◽  
D.I. Givens
Keyword(s):  
Rumen Fermentation ◽  
Gas Production ◽  
Different Types

The gas production (GP) technique has been established to estimate the rate and extent of rumen fermentation of feeds. Different types of apparatus have been developed to measure GP profiles, and these may have, an effect on the profiles observed. The aim of this experiment was to compare three such apparatus in terms of the GP profile obtained when all other aspects of the method were kept constant.

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