Practical Energy Efficiency Optimization
Presenting basic information for optimizing power plants, this book uses review exercises and practical case studies to provide real-world applications on maintaining optimal efficiency.
TABLE OF CONTENTS Practical Energy Efficiency Optimization
Appendix G: Basic Turbine Operation
Turbine Types
Turbines are prime movers used for driving rotating equipment like pumps and compressors or for generating electricity required for process industries. Turbines using steam as the motive power are called steam turbines, while those using heat of combustion of fuels as motive power are called gas turbines.
Steam turbines are classified as
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Back-pressure
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Extraction/condensing turbines
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Total condensing turbines
Gas turbines are classified based on the fuel fired for combustion and may be used for driving the rotary equipment or for power generation:
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Gas fired
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Liquid fuel fired
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Waste heat
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Expansion turbines
Steam Turbines
Back-pressure turbine. In this type, steam enters the turbine chamber at high pressure and expands to low or medium pressure. Enthalpy difference is used for generating power/work. See figure G-1.
Figure G-1: Back-pressure turbine
Total condensing turbine. In this type, steam entering at high/medium pressure condenses in a surface condenser and work is done until it reaches the condensing pressure (vacuum). See figure G-2.
Figure G-2: Total condensing turbine
Extraction/Condensing Turbines
In an extraction/condensing steam turbine, high-pressure steam enters the turbine and passes out from the turbine chamber in stages. Figure G-3 shows a two-stage extraction/condensing turbine. In this, medium-pressure steam and low-pressure steam pass out to meet the process needs. Balance quantity condenses in the surface condenser. The energy difference is used for generating power. This configuration meets the heat-power requirement of the process.
Figure G-3: Extraction/condensing turbine
Gas Turbines
In the case of gas turbines, fuel is burnt in a combustor...
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