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04203 Comparative analysis of the factors affecting small and medium scale gas turbine cogeneration in Australia and the UK
10
Engines (power generation
and propulsion,
electric vehicles)
Transport limitations in pyrolysing coal particles 96104196 Wutti, R. et al., Fuel, May 1996, 75, (7) 843-850. Pyrolysis of coal is controlled by chemical kinetics and several transport processes to and inside a coal particle. In nearly all calculations on combustion of solid fuels, the particles are assumed to be so small as to have no internal temperature or concentration gradients. The boundary conditions for which this assumption is permissible are compiled in this paper on the basis of accurate simulation. A one-dimensional mathematical model was used to determine the influence of mass and heat transport processes on the overall devolatilization rate of a coal particle. A two mixture fraction ap roach for modelin tur96104199 bulent combustion of coal volatlles an cpchar oxidation pro %ucts Coal Sci. Technol., 1995, 24, (2), Flare, D. V. and Fletcher, T. H. 1767-1770. A two-mixture fraction approach was used in the modelling of turbulent combustion of coal volatiles and semicoke oxidation products. One mixture fraction was used to distinguish between primary and secondary air streams, and two progress variables were used to treat mixing between oxidizers and pulverized coal combustion products. The predicted temperatures and major gas species concentrations between the one- and two-coal mixture fraction approaches were not very different, although the predictions for NO were significantly better using the two-coal-mixture fraction approach.
10 ENGINES Power Generation Vehicles
and Propulsion,
Electric
After CHP quantlty, It’s time for CHP quallty 96104200 Holwerda, B. Gas (Nerherlands), Apr. 1996. 116, (4), 22-24. (In Flemish) Since the 1994 reflection period the turbulent development of combined heat and power production (CHP) in the Netherlands seems to have slackened off. However, the opportunities for CHP are still superfluous and the high ambitions and goals are still unchanged. The goal is set at 8000 MW<, by the year 2000 and another 6000 MWc, in the years after that. More and more attention is now being paid to quahty. And shortly the first independent ‘energy contractors’ will introduce themselves on the market. Biomass gaslfler gas turblne power generatlng 96lO4201 technology Williams, R. H. and Larson, E. D. Biojnass & Eioerterg)?, 1996, 10, (2) 149-166. Integrating gasifiers with gas turbines, aeroderivative gas turbines in particular, makes it possible to achieve high efficiencies and low unit capital costs in modest-scale biomass power generating facilities. Electricity produced with biomass-integrated gasifier/gas turbine (BIG/CT) power systems would be competitive with electricity produced from coal and nuclear energy under a wide range of circumstances. Biomass also offers major environmental benefits. Initial applications will be with biomass residues generated in agro- and forest-produced industries. Eventually, biomass grown for energy purposes on dedicated energy farms will also be used to fuel these gas turbine systems. Continuing improvements in jet engine and biomass gasification technologies will lead to further gains in the performance of BIG/GT systems over the next couple of decades. 96104202 Coal-flred gas turblne and ash separatlon system Povitsky, A. and Goldman, Y. Fuel, Apr. 1995, 75, (5) 551-559. Application of a coal-fired gas turbine for combined-cycle power generation is discussed. A cycle with staged coal treatment, a counterflow combustor and an aerodynamic ash separation cyclone is chosen and its principal components are investigated. Conditions for self-stabilizing char (solid product of coal gasification) combustion are found experimentally and by numerical simulation. It is shown that the obstacle of sticking ash can be obviated by staged combustion of the char and products of mild coal gasification. Experiments carried out with a coal-fired gas turbine at the Technion Combustion Laboratory are described. The main component making it feasible and reliable is an ash separation device, whose performance is analysed experimentally and computationally. Comparatlve analysls of the factors affecting small 96104203 and medium scale gas turblne cogeneration In Australla and the UK Prince, R. G. and Poole, M. L. Chern. Eny. Rex Des., 1995, 73, (8) 967-973. Describes the development of a model to analyze the economics of retrofitting gas turbine cogeneration to industrial sites with electric loads in the range 3 to 30 MW, and with a wide range of heat loads. The model compares the cost of operating the cogeneration plant with the cost of generating steam in gas or coal-fired package boilers and purchasing power from the local supply authority. The performance modelling of gas turbines is based on analysis of a large number of modern industrial and aeroderivate machines.
292
Fuel and Energy
Abstracts
July
1996
Comparison of combined heat and power genera96104204 tion plants Rohrer, A. AEB Review, 1996, (3), 24-32. Discusses how combined heat and power (CHP) generation, or ‘cogeneration’, is possible with steam turbines, gas turbines or a combination of the two in a so-called combined cycle. Each of these options has specific advantages that depend on the fuel type, production costs for electricity and heat, type of cogeneration and output range. A comparison of their respective economics, power or heat efficiency and control characteristics, shows that, in the majority of cases, the combined cycle is the most economical option and offers most benefits. Of special interest are power plants with an electrical output of about 25 MW and above, since this is the size of plant that industry and public utilities generating electricity and heat require. Development of gas engines for stationary applica96104205 tions (combined heat and power) De Witt, J. TFVVS Danvak, Nov. 1995, 31, (13), 18-225. (In Danish) Describes the current efficiency and emission ratings of a number of Danish installations. The reported measurements result include the latest natural gas fired models as well as biogas-fired spark ignition engines. Also notes the developments made in gas engines over the past five years. Diesel combustion of an alkylated polycyclic aro96104206 matic hydrocarbon Tancell, P. J. et al., Fuel, May 1996, 75, (6), 717-723. The combustion of an alkylated PAH in a direct-injection diesel engine bas been investigated using a low-aromatic diesel fuel spiked with 2- and 3ethylphenanthrene. Exhaust samples were collected using a total exhaust solvent stripping apparatus (TESSA). The 2-and 3-ethylphenanthrene were recovered in yields of 0.3 and 0.35 wt% respectively. The major production from the combustion of ethylphenanthrene was shown to be vinylphenanthrene, produced in a yield of 0.01 wt% of the total added ethylphenanthrene. Although there was no increase in the emission of phenanthrene or other PAH, a statistically significant increase in the emission of 3-methylphenanthrene was observed. These results suggest that for these isomers, under the engine conditions used, no significant dealkylation occurs. Hospitals and cogeneratlon plant 96104207 Taddia, C. and Foa, P. Cmdiz. dell’Aria, Nov. 1995, 39, (ll), 1169-1176. (In Italian) The authors argue that combined heat and power (cogeneration) plants in hospitals is only a profitable investment if it is managed by qualified personnel. Provides the monitored results of the cogeneration plant for the Sestri Levante Hospital over a year of operation compared with the figures for the following year, when the plant was not operational following an accident. 96104208 Japan tests air blown IGCC Kaneko, S. er al., MPS, Modern Power Sysrems, Apr. 1996, 16, (4), 19, 21-22. Reports that recent runs on a pilot plant have convinced Mitsubishi that air blown gasification is feasible for Integrated Coal Gasification Combined Cycle (IGCC) systems, and they are now making plans for a full size installation. LQG/LTA robust controller of cogeneratlon plant 96104209 for disturbance rejectton In electric frequency and steam pressure Kim, B. H. et al., Elecrrical Power & Energy Systems, May 1996, 18, (4), 239-250. A robust controller design is considered for reducing the sensitiveness of electric frequency and extraction steam pressure to the disturbances imposed on a cogeneration plant by applying LQGiLTR methodology. A sample cogeneration plant that includes the dynamics of the extraction condensing turbine and generator, actuators and valves, governor, and PID controllers is modelled as the 15th-order differential equation for controller design. Simulation results demonstrate the preferable performance of the LQGiLTR controller in disturbance rejection. 96104210 The new combined heat and power station for Potsdam Sud Schmidt, K. Eurolrear & Pwr. Fern. Internat., Dec. 1995, 24, (12), 686-692. (In German) Outlines the division between district heating, natural gas supply and power supply in Potsdam. Describes the new combined heat and power plant for Potsdam. 96104211 The reject for gaslflcatlon Integrated wlth a comblned cycle (GIC i ) of Puertollano Sendin, U. Energia (Madrid), 1995, 21, (5), 43-50. (In Spanish) Describes how coal and petroleum coke are gasified together and the gas used to produce electricity. The facility can run with any fossil fuels, has high yields. is relatively non-polluting, produces a recyclable waste, and can use gas very efficiently.
Engines (power generation
and propulsion,
electric vehicles)
Transport limitations in pyrolysing coal particles 96104196 Wutti, R. et al., Fuel, May 1996, 75, (7) 843-850. Pyrolysis of coal is controlled by chemical kinetics and several transport processes to and inside a coal particle. In nearly all calculations on combustion of solid fuels, the particles are assumed to be so small as to have no internal temperature or concentration gradients. The boundary conditions for which this assumption is permissible are compiled in this paper on the basis of accurate simulation. A one-dimensional mathematical model was used to determine the influence of mass and heat transport processes on the overall devolatilization rate of a coal particle. A two mixture fraction ap roach for modelin tur96104199 bulent combustion of coal volatlles an cpchar oxidation pro %ucts Coal Sci. Technol., 1995, 24, (2), Flare, D. V. and Fletcher, T. H. 1767-1770. A two-mixture fraction approach was used in the modelling of turbulent combustion of coal volatiles and semicoke oxidation products. One mixture fraction was used to distinguish between primary and secondary air streams, and two progress variables were used to treat mixing between oxidizers and pulverized coal combustion products. The predicted temperatures and major gas species concentrations between the one- and two-coal mixture fraction approaches were not very different, although the predictions for NO were significantly better using the two-coal-mixture fraction approach.
10 ENGINES Power Generation Vehicles
and Propulsion,
Electric
After CHP quantlty, It’s time for CHP quallty 96104200 Holwerda, B. Gas (Nerherlands), Apr. 1996. 116, (4), 22-24. (In Flemish) Since the 1994 reflection period the turbulent development of combined heat and power production (CHP) in the Netherlands seems to have slackened off. However, the opportunities for CHP are still superfluous and the high ambitions and goals are still unchanged. The goal is set at 8000 MW<, by the year 2000 and another 6000 MWc, in the years after that. More and more attention is now being paid to quahty. And shortly the first independent ‘energy contractors’ will introduce themselves on the market. Biomass gaslfler gas turblne power generatlng 96lO4201 technology Williams, R. H. and Larson, E. D. Biojnass & Eioerterg)?, 1996, 10, (2) 149-166. Integrating gasifiers with gas turbines, aeroderivative gas turbines in particular, makes it possible to achieve high efficiencies and low unit capital costs in modest-scale biomass power generating facilities. Electricity produced with biomass-integrated gasifier/gas turbine (BIG/CT) power systems would be competitive with electricity produced from coal and nuclear energy under a wide range of circumstances. Biomass also offers major environmental benefits. Initial applications will be with biomass residues generated in agro- and forest-produced industries. Eventually, biomass grown for energy purposes on dedicated energy farms will also be used to fuel these gas turbine systems. Continuing improvements in jet engine and biomass gasification technologies will lead to further gains in the performance of BIG/GT systems over the next couple of decades. 96104202 Coal-flred gas turblne and ash separatlon system Povitsky, A. and Goldman, Y. Fuel, Apr. 1995, 75, (5) 551-559. Application of a coal-fired gas turbine for combined-cycle power generation is discussed. A cycle with staged coal treatment, a counterflow combustor and an aerodynamic ash separation cyclone is chosen and its principal components are investigated. Conditions for self-stabilizing char (solid product of coal gasification) combustion are found experimentally and by numerical simulation. It is shown that the obstacle of sticking ash can be obviated by staged combustion of the char and products of mild coal gasification. Experiments carried out with a coal-fired gas turbine at the Technion Combustion Laboratory are described. The main component making it feasible and reliable is an ash separation device, whose performance is analysed experimentally and computationally. Comparatlve analysls of the factors affecting small 96104203 and medium scale gas turblne cogeneration In Australla and the UK Prince, R. G. and Poole, M. L. Chern. Eny. Rex Des., 1995, 73, (8) 967-973. Describes the development of a model to analyze the economics of retrofitting gas turbine cogeneration to industrial sites with electric loads in the range 3 to 30 MW, and with a wide range of heat loads. The model compares the cost of operating the cogeneration plant with the cost of generating steam in gas or coal-fired package boilers and purchasing power from the local supply authority. The performance modelling of gas turbines is based on analysis of a large number of modern industrial and aeroderivate machines.
292
Fuel and Energy
Abstracts
July
1996
Comparison of combined heat and power genera96104204 tion plants Rohrer, A. AEB Review, 1996, (3), 24-32. Discusses how combined heat and power (CHP) generation, or ‘cogeneration’, is possible with steam turbines, gas turbines or a combination of the two in a so-called combined cycle. Each of these options has specific advantages that depend on the fuel type, production costs for electricity and heat, type of cogeneration and output range. A comparison of their respective economics, power or heat efficiency and control characteristics, shows that, in the majority of cases, the combined cycle is the most economical option and offers most benefits. Of special interest are power plants with an electrical output of about 25 MW and above, since this is the size of plant that industry and public utilities generating electricity and heat require. Development of gas engines for stationary applica96104205 tions (combined heat and power) De Witt, J. TFVVS Danvak, Nov. 1995, 31, (13), 18-225. (In Danish) Describes the current efficiency and emission ratings of a number of Danish installations. The reported measurements result include the latest natural gas fired models as well as biogas-fired spark ignition engines. Also notes the developments made in gas engines over the past five years. Diesel combustion of an alkylated polycyclic aro96104206 matic hydrocarbon Tancell, P. J. et al., Fuel, May 1996, 75, (6), 717-723. The combustion of an alkylated PAH in a direct-injection diesel engine bas been investigated using a low-aromatic diesel fuel spiked with 2- and 3ethylphenanthrene. Exhaust samples were collected using a total exhaust solvent stripping apparatus (TESSA). The 2-and 3-ethylphenanthrene were recovered in yields of 0.3 and 0.35 wt% respectively. The major production from the combustion of ethylphenanthrene was shown to be vinylphenanthrene, produced in a yield of 0.01 wt% of the total added ethylphenanthrene. Although there was no increase in the emission of phenanthrene or other PAH, a statistically significant increase in the emission of 3-methylphenanthrene was observed. These results suggest that for these isomers, under the engine conditions used, no significant dealkylation occurs. Hospitals and cogeneratlon plant 96104207 Taddia, C. and Foa, P. Cmdiz. dell’Aria, Nov. 1995, 39, (ll), 1169-1176. (In Italian) The authors argue that combined heat and power (cogeneration) plants in hospitals is only a profitable investment if it is managed by qualified personnel. Provides the monitored results of the cogeneration plant for the Sestri Levante Hospital over a year of operation compared with the figures for the following year, when the plant was not operational following an accident. 96104208 Japan tests air blown IGCC Kaneko, S. er al., MPS, Modern Power Sysrems, Apr. 1996, 16, (4), 19, 21-22. Reports that recent runs on a pilot plant have convinced Mitsubishi that air blown gasification is feasible for Integrated Coal Gasification Combined Cycle (IGCC) systems, and they are now making plans for a full size installation. LQG/LTA robust controller of cogeneratlon plant 96104209 for disturbance rejectton In electric frequency and steam pressure Kim, B. H. et al., Elecrrical Power & Energy Systems, May 1996, 18, (4), 239-250. A robust controller design is considered for reducing the sensitiveness of electric frequency and extraction steam pressure to the disturbances imposed on a cogeneration plant by applying LQGiLTR methodology. A sample cogeneration plant that includes the dynamics of the extraction condensing turbine and generator, actuators and valves, governor, and PID controllers is modelled as the 15th-order differential equation for controller design. Simulation results demonstrate the preferable performance of the LQGiLTR controller in disturbance rejection. 96104210 The new combined heat and power station for Potsdam Sud Schmidt, K. Eurolrear & Pwr. Fern. Internat., Dec. 1995, 24, (12), 686-692. (In German) Outlines the division between district heating, natural gas supply and power supply in Potsdam. Describes the new combined heat and power plant for Potsdam. 96104211 The reject for gaslflcatlon Integrated wlth a comblned cycle (GIC i ) of Puertollano Sendin, U. Energia (Madrid), 1995, 21, (5), 43-50. (In Spanish) Describes how coal and petroleum coke are gasified together and the gas used to produce electricity. The facility can run with any fossil fuels, has high yields. is relatively non-polluting, produces a recyclable waste, and can use gas very efficiently.