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http://me-mechanicalengineering.com/comparison-between-closed-cycle-gas-turbine-and-open-cycle-gas-turbine/

http://me-mechanicalengineering.com/comparison-between-closed-cycle-gas-turbine-and-open-cycle-gas-turbine/

by ProGATE Andheri

Posted on July 27, 2016 at 07:24 AM

Comparison Between Closed Cycle Gas Turbine and Open Cycle Gas Turbine


Comparison Between Closed Cycle Gas Turbine and Open Cycle Gas Turbine can be done in 11 different criterias. Those 11 criterias are cycle of operation, working fuel used, type of fuel used, manner of heat input, quality of heat input, efficiency, part load efficiency, turbine blade life of a turbine, control on power production and cost of turbine plant installation compared in below table briefly.

S.no
Criterion
Closed Cycle Gas Turbine
1Cycle of operationIt works on closed cycle. The working fluid is recirculated again and again. It is a clean cycle.It works on open cycle. The fresh charge is supplied to each cycle and after combustion and expansion. It is discharged to atmosphere.
2Working fluidThe gases other than the air like Helium or Helium-Carbon dioxide mixture can be used, which has more favourable properties.Air-fuel mixture is used which leads to lower thermal efficiency.
3Type of fuel usedSince heat is transferred externally, so any type of fuel; solid, liquid or gaseous or combination of these can be used for generation of heat.Since combustion is an integral part of the system thus it requires high quantity liquid or gaseous fuel for burning in a combustion chamber.
4Manner of heat inputThe heat is transferred indirectly through aheat exchanger.Direct heat supply. It is generated in the combustion chamber itself
5Quality of heat inputThe heat can be supplied from any source like waste heat from some process, nuclear heat and solar heat using a concentrator.It requires high grade heat energy for generation of power in a gas turbine.
6EfficiencyHigh thermal efficiency for given lower and upper temperature liquids.Low thermal efficiency for same temperature limits.
7Part load efficiencyPart load efficiency is better.Part load efficiency is less compared to Closed cycle gas turbine.
8Size of plantReduced size per MWh of power output.Comparatively large size for same power output.
9Blade lifeSince combustion products do not come in direct contact of turbine blade, thus there is no blade fouling and longer blade life.Direct contact with combustion products, the blades are subjected to higher thermal stresses and fouling and hence shorter blade life.
10Control on power productionBetter control on power production.Poor control on power production.
11CostClosed cycle gas turbine plant is complex and costly.Open cycle gas turbine plant is simple and less costly.

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