Cogeneration is
two methods to produce electrical power energy from a single fuel source
using one energy source to produce two or more forms of output energy
combining two prime movers such as a gas turbine and diesel generator in one plant system
all needs are met by one energy source such as power generation, heating, air-conditioning
having two or more separate electricity generators in parallel on the same grid
A combined steam and gas turbine arrangement can be termed:
an ideal system
a cogeneration system
a once through system
ideal relative to system efficiency
a high capacity system
A cogeneration plant could consist of: 1. diesel engine with attached waste heat boiler 2. gas turbine using a boiler as the combustor 3. steam turbine exhausting to a process steam header 4. gas boiler using the exhaust gas from a gas turbine as combustion air
1,2
1,2,3
2,3,4
1,3,4
1,2,3,4
The main advantage of cogeneration is to
reduce total energy costs
reduce the number of operators required to operate the plant
quicker start up times as compared to conventional coal fired power plants
less environmental impact
all of the above
Topping cycle cogeneration is where
the fuel supplied is first utilized for a process due to the high thermal energy and the waste heat is utilized in a HRSG
the energy supplied to the electrical power grid is only operated during peak demand periods
the fuel supplied will first produce electrical power and the heat energy liberated is the byproduct
none of the above
Control strategies in a cogeneration system are dependant upon
type of available fuel
base load operation
peak load demands
type of facility
environmental impact
Control strategies used with cogeneration systems are: 1. thermal load 2. electrical load 3. environmental impact 4. duct burner and diverter 5. process demand 6. thermal efficiency
4,5,6
1,2,4
2,4,5
1,2,3,4,5,6
Cogeneration systems may include: 1. gas turbines 2. internal combustion engines 3. waste heat 4. steam turbines
3,4
The advantages of cogeneration at both the micro and macro levels include 1. wide range of configurations are possible 2. on site electricity 3. quick start-up times 4. pollution free fuel
The pollutants emitted form a cogeneration plant may include: 1. carbon monoxide 2. carbon dioxide 3. NOX 4. water 5. ammonia 6. sulphur dioxide
1,2,3,6
2,3,6
A cogeneration system that utilizes an internal combustion engine is best suited for:
low electrical loads at varying ambient air conditions
areas with little water supplies for cooling purposes
remote locations
peak demand locations
any of the above
A cogeneration system that utilizes an internal combustion engine extracts heat from the: 1. exhaust gases 2. lubrication oil system 3. engine water jackets 4. fuel system
Duct burner firing in an HRSG is utilized to: 1. produce steam when the gas turbine is off-line 2. increase steam production 3. control superheated steam temperature requirements 4. meet the process steam temperature requirements
Selective catalytic reduction refers to:
breaking down the fuels constituents to burn cleaner using a catalyst
decreasing the flue gas temperature by running it through a scrubber
giving the flue gas an ionic charge for particulate removal
lowering the total carbon dioxide emissions through a catalyst
lowering the NOX loading by using a catalyst
To lower NOX production selective catalytic reduction may be accomplished using:
ammonia
hydrogen
oxygen
methane
biofuels
